US20060002378A1 - Voice and data wireless communications network and method - Google Patents

Voice and data wireless communications network and method Download PDF

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Publication number
US20060002378A1
US20060002378A1 US11/193,772 US19377205A US2006002378A1 US 20060002378 A1 US20060002378 A1 US 20060002378A1 US 19377205 A US19377205 A US 19377205A US 2006002378 A1 US2006002378 A1 US 2006002378A1
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packet
packets
communications
access point
time duration
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US11/193,772
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Robert Beach
Jason Harris
Richard Montgomery
Wanda Sealander
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Symbol Technologies LLC
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Symbol Technologies LLC
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/50Allocation or scheduling criteria for wireless resources
    • H04W72/56Allocation or scheduling criteria for wireless resources based on priority criteria
    • H04W72/566Allocation or scheduling criteria for wireless resources based on priority criteria of the information or information source or recipient
    • H04W72/569Allocation or scheduling criteria for wireless resources based on priority criteria of the information or information source or recipient of the traffic information
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/50Allocation or scheduling criteria for wireless resources
    • H04W72/56Allocation or scheduling criteria for wireless resources based on priority criteria
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00Traffic control in data switching networks
    • H04L47/10Flow control; Congestion control
    • H04L47/24Traffic characterised by specific attributes, e.g. priority or QoS
    • H04L47/2425Traffic characterised by specific attributes, e.g. priority or QoS for supporting services specification, e.g. SLA
    • H04L47/2433Allocation of priorities to traffic types
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00Traffic control in data switching networks
    • H04L47/50Queue scheduling
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00Traffic control in data switching networks
    • H04L47/50Queue scheduling
    • H04L47/52Queue scheduling by attributing bandwidth to queues
    • H04L47/521Static queue service slot or fixed bandwidth allocation
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00Traffic control in data switching networks
    • H04L47/50Queue scheduling
    • H04L47/56Queue scheduling implementing delay-aware scheduling
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00Traffic control in data switching networks
    • H04L47/50Queue scheduling
    • H04L47/62Queue scheduling characterised by scheduling criteria
    • H04L47/621Individual queue per connection or flow, e.g. per VC
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00Traffic control in data switching networks
    • H04L47/50Queue scheduling
    • H04L47/62Queue scheduling characterised by scheduling criteria
    • H04L47/622Queue service order
    • H04L47/6225Fixed service order, e.g. Round Robin
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00Traffic control in data switching networks
    • H04L47/50Queue scheduling
    • H04L47/62Queue scheduling characterised by scheduling criteria
    • H04L47/622Queue service order
    • H04L47/623Weighted service order
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W28/00Network traffic management; Network resource management
    • H04W28/02Traffic management, e.g. flow control or congestion control
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W8/00Network data management
    • H04W8/02Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
    • H04W8/04Registration at HLR or HSS [Home Subscriber Server]
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W84/00Network topologies
    • H04W84/02Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10Small scale networks; Flat hierarchical networks
    • H04W84/12WLAN [Wireless Local Area Networks]

Definitions

  • This invention relates to wireless local area networks (“LANs”), and more particularly, to wireless local area networks that carry a mixed traffic of voice and data.
  • LANs wireless local area networks
  • Wireless LANs are typically used in applications that involve mobile computers, in applications where wireline installation is not feasible, etc. Such applications include warehouse inventory tracking, portable point of sale, shipping and receiving, package tracking, etc.
  • the IEEE 802.11 communications standard has been used by some vendors to provide interoperability between wireless LAN equipment.
  • the 802.11 standard specifies a protocol in which information is transmitted in packets.
  • the standard specifies features such as packet size, packet content information, data rates, roaming, etc.
  • the primary type of information that was initially transmitted in systems that were designed to the 802.11 standard as published was information such as barcode information, point of sale information, package tracking information, etc.
  • several remote terminals may be in communications with a single access point to receive and transmit information such as bar code information, point of sale information, package tracking information, etc.
  • the standard as published specifies a communications medium that is shared by transmitters (e.g., an access point and one or more remote terminals).
  • the standard further specifies that packet size may vary.
  • a remote terminal that has a relatively large packet to transmit may need to occupy the shared communications medium for a longer period than a remote terminal that has a relatively short packet to transmit.
  • delays in communicating packets have typically been non-critical to providing communications at least partly because of the type of information that has been transmitted in such systems.
  • Information such as bar code information, package tracking information, etc. typically remains valid until a next incremental event occurs (e.g., until bar code information has changed, until a package is tracked to a next point in route, etc.). In addition, such information does not generally effect system communications if delivered with some delay.
  • packets are simply transmitted in the order in which they have been received for transmission.
  • a packet that is transmitted without being properly acknowledged by its intended recipient is repeated for a predetermined number of times while transmission of other remaining packets is delayed. After retransmitting a packet for a predetermined number of times without receiving a proper acknowledgment, the transmitter may proceed to transmit the remaining packets.
  • Some known wireless LANs carry voice signals as part of the communications traffic but these systems are deficient in effectively meeting such complex communications demands as discussed above. Moreover, there may be a need to meet such demands with existing systems without substantially increasing system complexity, structure, design, cost, etc.
  • a mixed traffic voice and data communications transmitter and network may be provided.
  • the communications network may be a wireless local area network that uses packet based communications.
  • the communications network may include at least one access point that receives voice and other communications for transmission to terminals that are associated with the access point.
  • a transmitter may prioritize packets. Prioritization may be based on when each packet has been received, whether the packets contain voice communications, whether the packets contain network-management communications, whether the packets contain data communications (e.g., communications other than for voice or network management), whether the packet is directed to a voice-capable unit, whether a packet was transmitted using a particular communications protocol, etc.
  • a transmitter such as an access point, may prioritize packets for transmission based on to which receiver terminal the packets have been addressed. Packets may be separated into queues with each queue storing the packets that have been received for transmission to a particular terminal. Packets may be further prioritized within each queue.
  • Prioritized packets may be transmitted in a sequence that allows a fair opportunity to each terminal to receive the same number of packets. For example, packets may be transmitted in rounds. In each round, the highest priority packet for each terminal may be transmitted (e.g., in a one packet per round per terminal fashion). In each round, an equal number of packets may be transmitted to each terminal (e.g., one per packet).
  • an acknowledgment (e.g., an acknowledge packet) from a receiving terminal may be required before the transmitter discards the transmitted packet or moves onto transmitting the next packet for that terminal.
  • a transmitter may repeatedly transmit a packet until it is acknowledged or until a retry threshold (e.g., a total number of times that a packet is to be transmitted) has been reached.
  • the retry threshold may be determined based on whether the packet that is being retransmitted is for voice communications.
  • the retry threshold for voice communications may be lower than for other communications.
  • a packet may be retransmitted when the number of times the packet has been transmitted reaches an initial retry threshold.
  • retransmission may be discontinued until after a frequency hop in modulation. Thereafter, retransmissions may resume until an acknowledgment is received or until a total retry threshold has been reached.
  • the initial and total retry thresholds may vary based on whether the packet that is being retransmitted is for voice communications. New packets that are received and prioritized may have a higher priority than an unacknowledged packet.
  • New packets that are received and prioritized may have a higher priority than unacknowledged packets.
  • Retransmission of an unacknowledged packet may be preempted when a packet with a priority that is higher than the packet being retransmitted is received.
  • a transmitter may transmit a newly received packet for a particular terminal over other earlier received packets for that same terminal when the newly received packet is determined to have a higher priority than the other packets.
  • An unacknowledged packet may then be retransmitted in a later round.
  • FIG. 1 is a diagram of an illustrative communications network that includes an illustrative wireless local area network in accordance with the present invention
  • FIG. 2 a is a flow chart of illustrative steps involved in managing packet traffic for use in a transmitter in accordance with the present invention
  • FIG. 2 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 2 a in accordance with the present invention
  • FIG. 3 a is a flow chart of illustrative steps involved in transmitting packets in accordance with the present invention
  • FIG. 3 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 3 a in accordance with the present invention
  • FIG. 4 a is a flow chart of illustrative steps involved in managing packet traffic based on which packets are for voice in accordance with the present invention
  • FIG. 4 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 4 a in accordance with the present invention
  • FIG. 5 a is a flow chart of illustrative steps involved in managing packet traffic based on which packets are for network management in accordance with the present invention
  • FIG. 5 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 5 a in accordance with the present invention
  • FIG. 6 a is a flow chart of illustrative steps involved in managing packet traffic with multiple levels of priority in accordance with the present invention
  • FIG. 6 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 6 a in accordance with the present invention
  • FIG. 7 a is a flow chart of illustrative steps that are involved in managing packet traffic based on which terminals are voice capable in accordance with the present invention
  • FIG. 7 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 7 a in accordance with the present invention
  • FIG. 8 a is a flow chart of illustrative steps involved in managing traffic based on determining which terminals are voice capable in accordance with the present invention
  • FIG. 8 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 8 a in accordance with the present invention
  • FIG. 9 a is a flow chart of illustrative steps involved in using variable contention windows in accordance with the present invention.
  • FIG. 9 b is a diagram of illustrative durations for contention windows in accordance with the present invention.
  • FIG. 10 a is a flow chart of illustrative steps involved in transmitting packets in accordance with the present invention.
  • FIG. 10 b is a flow chart of illustrative packet-based communications that are based on the illustrative steps of FIG. 10 a in accordance with the present invention
  • FIG. 11 a is a flow chart of illustrative steps involved in packet-based communications using frequency hopping in accordance with the present invention
  • FIG. 11 b is a flow chart of illustrative packet-based communications that are based on the illustrative steps of FIG. 11 a in accordance with the present invention
  • FIG. 12 a is a flow chart of illustrative steps involved in incrementally transmitting packets in accordance with the present invention.
  • FIG. 12 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 12 a in accordance with the present invention.
  • the present invention improves mixed traffic voice communications for wireless local area networks (“LANs”) by substantially meeting the communications demands that have been mentioned above.
  • Packets that are to be transmitted in a wireless LAN over a half-duplex communication medium are transmitted in order of priority.
  • Priority may be determined based on at least whether a particular packet is for providing voice communications.
  • One technique for determining whether a packet is for voice communications is to determine whether the intended recipient of the packet has been identified to be voice-capable and further determining whether the packet was received for transmission using a particular communications protocol (e.g., a protocol typically used to send voice communications).
  • a particular communications protocol e.g., a protocol typically used to send voice communications.
  • Other techniques for prioritizing packets for transmission and for determining which packets are for voice communications are discussed below.
  • Packets may be distributed fairly by transmitting packets in rounds where in each round one packet (e.g., the highest priority packet) is transmitted for every receiver (e.g., a remote terminal). In the case of a packet that is transmitted without being acknowledged by its intended recipient, the packet may be retransmitted in the next round of transmissions except for when another packet with a higher priority than the unacknowledged packet has been recently received for transmission to the same terminal. The recently received packet with a higher priority will be transmitted before the unacknowledged packet is transmitted again.
  • the number of times a packet is retransmitted may be determined based on whether the packet is for providing voice communications. Priority may also be given to voice communications by using techniques that are discussed below that give greater access to the communications medium to transmitters that are about to transmit packets that are for voice communications.
  • wireless local area network (“LAN”) 20 may include a plurality of cells 22 .
  • Cell 22 may include an access point 24 (which is sometimes referred to as a wireless local bridge).
  • Cell 22 may include remote terminals 26 .
  • Each terminal 26 may be a mobile, portable, or stationary terminal.
  • Each terminal 26 may be a desktop workstation, laptop computer, palm top computer, handheld personal computer, pen-based computer, personal digital assistant, handheld scanner, data collector, handheld printer, etc.
  • Each terminal 26 may include wireless-network-interface resources that are configured to provide two-way radio or infrared signal communications.
  • Such resources may include an interface card (or an external modem), a software driver, and an antenna.
  • Other suitable resources may also be used, but for clarity and brevity, the wireless network interface resources will be discussed primarily in the context of an interface card, a software driver, and an antenna.
  • the interface card may have been configured to use a standard computer-bus interface (e.g., ISA, PCMCIA, etc.) or standard computer port (e.g., Rs232, RS422, etc.) to provide convenient access to terminal equipment.
  • a network-operating-system may be implemented on each terminal 26 .
  • the interface card may be coupled to the network-operating-system application using the software driver.
  • the interface card for each remote terminal 26 may be a network-communications interface.
  • the network interface card for each terminal 26 are typically implemented to use a carrier sense access protocol and to modulate communications signals with a spreading sequence.
  • Access point 24 may be an interface for communicating between wireless network 20 and a wireline network. Access point 24 may be configured to provide a communications gateway between terminals 26 that are in cell 22 and between a wireline network and the terminals 26 . Access point 24 may include a resource(s) (e.g., software, hardware, or a combination thereof) that is configured to connect the access point to a wireline network (e.g., on ethernet network, a token ring network, etc.). Access point 24 is typically configured to convert signals between wireline and wireless communications mediums. The conversion may allow the access point to pass communication information between the wireline network and wireless remote terminals 26 .
  • a resource(s) e.g., software, hardware, or a combination thereof
  • a wireline network e.g., on ethernet network, a token ring network, etc.
  • Access point 24 is typically configured to convert signals between wireline and wireless communications mediums. The conversion may allow the access point to pass communication information between the wireline network and wireless remote terminals 26
  • Access points are typically provided with sufficient processing, hardware, software, etc. to operate in compliance with the IEEE 802.11 (e.g., to provide 802.11 roaming, standard 802.11 data rates, etc.) and to provide additional features that are developed by a vendor.
  • Access point 24 may be implemented using a personal computer (e.g., a Power PC, an IBM compatible computer), server, workstation, etc., having an appropriate operating system, wireless-network-interface resources, wireline-network-interface resources, network-operating-system applications, etc.
  • Access point 24 and remote terminals 26 may be configured to communicate using spread spectrum modulation techniques (e.g., direct sequence spread spectrum modulation, frequency hopping spread spectrum modulation, etc.).
  • spread spectrum modulation techniques e.g., direct sequence spread spectrum modulation, frequency hopping spread spectrum modulation, etc.
  • the IEEE 802.11 standard specifies the format and content of communications packets. Communications packets that may also be referred to as frames may be of variable size with the size of each packet being identified in packet header information. In some embodiments, the body of each packet may vary from 0 to 2312 octets.
  • Access point 24 may manage the communications traffic between terminals 26 and the wireline network. Access point 24 may manage the communications traffic by controlling when packets are transmitted to each remote terminal 26 in cell 22 .
  • the communications traffic in cell 22 may include data packets (e.g., signals that carry packets to provide data communications), voice packets (e.g., signals that carry packets to provide voice communications), real-time packets (e.g., signals that carry packets to provide real-time communications such as multimedia or voice communications), management packets (e.g., signals that carry packets to provide network management communications), etc.
  • data packets e.g., signals that carry packets to provide data communications
  • voice packets e.g., signals that carry packets to provide voice communications
  • real-time packets e.g., signals that carry packets to provide real-time communications such as multimedia or voice communications
  • management packets e.g., signals that carry packets to provide network management communications
  • the wireline network that is coupled to access point 24 may include equipment 23 that is configured to implement the wireline network.
  • the wireline network may be coupled to an external network (e.g., PBX, PSTN, Internet, etc.).
  • Access point 24 may manage communications traffic by prioritizing packets that are to be transmitted to the remote terminals 26 that are associated with access point 24 . Illustrative steps involved in managing communications traffic for use in an access point such as access point 24 of FIG. 1 are shown in FIG. 2 a .
  • an access point may receive signals carrying packets that are to be transmitted to remote terminals (e.g., packets that are addressed to individual terminals 26 in cell 22 of FIG. 1 ).
  • the access point may prioritize the received packets for transmission. An access point may prioritize received packets to determine to which remote terminal to transmit a packet next and to determine which one of the packets that are to be transmitted to that remote terminal will be the packet to be transmitted next.
  • Prioritization may be performed in intervals as packets are received by the access point. For example, prioritization may be performed at regular periodic intervals. Each packet may be prioritized based on time of reception, packet content, packet address information, message protocol, fairness to each terminal, etc.
  • queue 44 includes illustrative packets in the order in which they were received by an access point.
  • the packets in queue 44 may have been received from remote terminals that are associated with the access point or from a wireline network.
  • the packets in queue 44 are packets that are directed to four terminals T 1 , T 2 , T 3 and T 4 .
  • Queues 46 , 48 , 50 and 52 may include packets from queue 44 when the packets have been prioritized by the access point. Each respective queue 46 , 48 , 50 and 52 is a queue that is associated with a respective terminal T 1 , T 2 , T 3 , and T 4 . Within each queue 46 , 48 , 50 and 52 packets may have been prioritized based on when the packets were received.
  • Each packet illustrated in queue 44 has a terminal address and a packet number.
  • the packet number is used here for illustrative purposes to show the order in which packets were received by the access point.
  • packets with lower packet numbers are higher in transmission priority because they were received first.
  • Packets may be transmitted based on priority. Illustrative steps involved in transmitting packets are shown in FIG. 3 a .
  • an access point may prioritize packets for transmission.
  • the prioritized packets may be distributed by transmitting packets based on priority, based on fairness, based on fairness and priority, based on fairness per terminal, based on a one packet per terminal transmission sequence, etc. If desired, fairness may be determined as part of step 54 when the access point prioritizes packets.
  • Illustrative queues 58 , 60 , 62 , 64 and 66 of FIG. 3 b may be provided based on the illustrative steps of FIG. 3 a .
  • Queues 58 , 60 , 62 and 64 may each be associated with a respective terminal (T 1 , T 2 , T 3 , and T 4 ).
  • the packets may have been received by an access point for transmission to terminals (T 1 , T 2 , T 3 , and T 4 ).
  • the packets may have been prioritized based on time of reception.
  • the access point may transmit packets in rounds. In each round, the access point may transmit the same number of packets (e.g., one packet) to each terminal.
  • Queue 66 includes the packets from queues 58 , 60 , 62 and 64 in the sequence in which the packets are to be transmitted.
  • the sequence may be divided into rounds with each round including one packet per terminal. As shown, the first and second rounds each have four packets, one for each terminal that is associated with the access point.
  • the third round includes three packets because there are no more packets that are pending to be transmitted to T 3 in queue 62 after the first two rounds were successfully transmitted.
  • An access point may select and transmit packets for each terminal in each round in the order in which that the packets for that terminal were received by the access point.
  • the access point transmits packets nos. 2 , 3 , 6 and 1 that are each the first packet in queues 58 , 60 , 62 , and 64 , respectively.
  • the access point transmits packets nos. 4 , 8 , 7 and 5 that are each the next packet that was received for each terminal T 1 , T 2 , T 3 and T 4 , respectively.
  • one packet from each queue is transmitted without having competition between the queues for a position in the round.
  • the illustrative packets in FIG. 3 b are variable size packets.
  • the packets are illustrated as fixed length packets to simplify the figures.
  • the access point may prioritize packets based on which packets are for voice communications. Illustrative steps involved in prioritizing packets based on which packets are for voice communication are shown in FIG. 4 a .
  • an access point may determine which of the packets that are to be transmitted are for voice communications.
  • Packets that are for voice communications may be packets that carry digitized voice communications. As discussed above, voice communications typically have stricter transmission requirements than other communications such as inventory data, point of sale information, etc.
  • the access point may determine which packet is for voice based on a message flag in the packet, based on the packet being addressed to a voice-capable terminal, based on the messaging protocol (discussed further below), etc.
  • packets may be prioritized based on determining which packets are for voice. Packets for voice communications may be prioritized higher than other packets.
  • Illustrative queues 72 , 74 and 76 of FIG. 4 b may be provided based on the illustrative steps of FIG. 4 a .
  • Queue 72 may include packets that have been received by an access point for transmission to terminals T 1 and T 2 .
  • Queue 72 includes packets that are to be transmitted to provide voice communications (packets nos. 1 , 4 and 6 ). Packets that are for voice communications are prioritized higher than other packets in queues 74 and 76 so that these voice packets are transmitted before other packets.
  • Queue 74 for terminal T 1 includes voice packet no. 6 that is prioritized higher than packets nos. 3 and 5 which were received before packet no. 6 .
  • Queue 76 for terminal T 2 includes voice packets nos.
  • each queue voice packets are prioritized to be transmitted before other packets. All packets in a queue are further prioritized for transmission based when each packet was received by the access point.
  • An access point may prioritize packets based on network management requirements. Illustrative steps involved in prioritizing packets based on network management requirements are shown in FIG. 5 a .
  • the access point may determine which ones of the packets are to be transmitted to manage network operations. Packets are determined to be for network management based on a message flag, message length, etc.
  • packets may be prioritized based on which packets are for network management.
  • Illustrative queues 82 , 84 and 86 of FIG. 5 b may be provided based on the illustrative steps of FIG. 5 a .
  • Queue 82 of received packets may include packets nos. 1 , 4 and 6 that are to be transmitted to provide network management. Management packets may be prioritized higher than other packets to protect the integrity of network operations.
  • Queues 84 and 86 may be implemented for terminals T 1 and T 2 , respectively.
  • Management packets nos. 1 and 4 are prioritized higher (i.e., positioned at top of the queue) than the other packet in queue 84 for T 1 and management packet no. 6 is prioritized higher than the other packets in queue 86 for T 2 .
  • the higher priority packets in each queue are to be transmitted before the lower priority packets in the queue.
  • packet traffic may be managed using different levels of priority. Illustrative steps involved in prioritizing packets with different levels of priority are shown in FIG. 6 a .
  • an access point may determine which packets are for providing voice, network management, or other communications.
  • packets that are for managing network operations are prioritized highest.
  • packets that are for voice communications are prioritized second highest.
  • packets that are for other communications are prioritized third highest.
  • Illustrative queues 96 , 98 , 100 and 102 of FIG. 6 b may be provided based on the illustrative steps of FIG. 6 a .
  • Queue 96 may include received packets that include voice, management and other communications packets that are to be transmitted for terminals T 1 , T 2 and T 3 .
  • Queues 98 , 100 and 102 may be implemented for terminals T 1 , T 2 and T 3 , respectively.
  • management packets are prioritized highest (i.e., higher than voice and other communications packets), voice packets are prioritized second highest, and other communications packets are prioritized third highest. Priority between packets that are for the same type of communications may be based on time of reception. Packets may be transmitted by the access point in the order of packet priority for each remote terminal.
  • OSI Open System Interconnect
  • ISO International Standard Organization
  • OSI specifies a complete set of network functions, grouped into seven layers. The seven layers are the physical layer (layer 1), data link layer (layer 2), network layer (layer 3), transport layer (layer 4), session layer (layer 5), presentation layer (layer 6) and application layer (layer 7).
  • the network functions are structured so that each OSI layer is supported by the layers below it.
  • the transport layer establishes and maintains communications between applications on different computers.
  • Communications protocols such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) operate at the transport layer.
  • TCP Transmission Control Protocol
  • UDP User Datagram Protocol
  • TCP provides full-duplex connection-oriented services (i.e., maintains a virtual communications connection between end users) while UDP provides connection-less-oriented services (i.e., provides communications between end users without maintaining an open connection).
  • the communications protocol that is typically used for voice communications in the network layer is UDP.
  • an access point may determine which terminals are voice capable.
  • the access point may determine which terminals are voice capable based on a message flag in a packet, on pre-assigned addresses for voice-capable terminals, etc.
  • the access point may receive packets for transmission to the terminals. Step 106 may be performed before, after, or during step 104 .
  • the access point may prioritize packets. Prioritization may be based on a plurality of factors. Prioritization may be based on to which terminal a packet is directed, based on the communications protocol of the packet, based on whether the packet is for network management, and further based on time of reception.
  • packets may be transmitted. Packets may be transmitted based on how the packets were prioritized and based on fairness (e.g., maintains fairness by maintaining an equal distribution of packets among the remote terminals).
  • Illustrative queues 112 , 114 , 116 , 118 and 120 of FIG. 7 b may be implemented based on the illustrative steps of FIG. 7 a .
  • Queue 112 may be a queue of received packets that are positioned in the queue 112 in the order in which they were received by an access point. Terminals T 1 , T 2 and T 3 may have already been associated with the access point when the packets were received by the access point.
  • Queues 114 , 116 and 118 may be implemented for terminals T 1 , T 2 and T 3 , respectively, when the received packets are prioritized.
  • the access point may have determined that terminal T 1 is a voice-capable terminal before the packets in queue 112 were received.
  • Packets that are to be transmitted to manage the wireless network may have been prioritized highest.
  • Queue 112 includes two management packets, packet no. 1 which is directed to terminal T 1 (e.g., addressed to terminal T 1 ) and packet no. 9 which is directed to terminal T 3 .
  • Queue 114 for terminal T 1 is implemented to have packet no. 1 have the highest priority in queue 114 and queue 119 for terminal T 3 is implemented to have packet no. 9 have the highest priority in queue 119 .
  • Packets that are to be transmitted to provide voice communications may have been prioritized second highest.
  • the communications protocols of the OSI transport layer handle packets without determining whether the packets are for voice communications.
  • Some networks that are implemented using the OSI transport layer use UDP for providing voice communications.
  • An access point may determine which packets are for voice based on the communications protocol of the packets (e.g., UDP) and based on whether the packet is directed to a voice-capable terminal.
  • Communications protocols operating in the transport layer i.e., TCP and UDP
  • IP Internet Protocol
  • IP packets include a protocol field that indicates that the enclosed packets are for which protocol in the Transport Layer (e.g., UDP, TCP, etc.).
  • Packets may be received by an access point from a half-duplex communications medium (e.g., a radio frequency channel) that is shared between the access point and remote terminals on which remote terminals communicate with the access point and received from another communications medium on which a wireline network communicates with the access point.
  • Packets may have been transmitted to the access point using Internet Protocol (e.g., using IP packet formats) for Network Layer communications and using UDP, TCP, etc. (e.g., using UDP packet formats) for Transport Layer communications. Accordingly, packets that are received by the access point from the remote terminals may already be in conformance with the communications requirements for IP and UDP, TCP, etc.
  • the access point may configure packets to conform to the 802.11 standard (e.g., when two remote terminals in the wireless LAN are communicating).
  • the access point may read the protocol field of received IP packets to determine the Transport Layer communications protocol of received packet. Packets which are to be handled using UDP and which are directed to a voice-capable terminal may be determined by the access point to contain voice communications.
  • the access point may have determined earlier which terminals are voice-capable through an earlier exchange with the terminals. The earlier exchange may occur when a remote terminal initially seeks to establish communications with (e.g., be associated with) an access point. If desired, the access point may have been programmed with information related to the capabilities of each terminal.
  • queue 114 for voice-capable terminal T 1 includes packet no. 7 (UDP) and packet no. 10 (UDP) which are both prioritized higher than packet no. 3 that was received before them.
  • UDP packet no. 7
  • UDP packet no. 10
  • queues 116 and 118 UDP packets are not prioritized higher than TCP packets since the access point has not determined that T 2 and T 3 are voice-capable.
  • management packets are prioritized highest with all other packets being prioritized second highest.
  • Queue 120 includes the packets in the order in which they are to be transmitted (i.e., the transmission sequence). Packets may be transmitted in one-packet-per-terminal rounds with the highest priority packet for each terminal being transmitted in each round. Such transmission techniques allow for the quick delivery of voice communications without substantially increasing the complexity, cost, structure, or design of network equipment.
  • Queues 114 , 116 and 118 may have been configured to be of equal size. Queues of equal size may prevent the situation in which a large number of packets for one terminal occupies most of the storage space of the access point. Such a situation may block new packets that are received by the access point to be stored due to insufficient storage space.
  • the size of such equal sized queues may be determined based on system limitations. For illustrative purposes, queues 114 , 116 and 118 are each shown to be capable of storing only four packets.
  • a terminal may transmit a packet that includes a voice flag to an access point.
  • the voice flag may be set to indicate that the terminal is voice-capable.
  • the access point may determine the status of the terminal by receiving the packet and reading the voice flag of the packet.
  • the access point may store information indicating the voice-capable status of the terminal.
  • the access point may prioritize packets based on the terminal having a voice-capable status.
  • Queue 128 and packet flow chart 130 of FIG. 8 b may be implemented based on the illustrative steps of FIG. 8 a .
  • Chart 130 indicates that terminal T transmitted to an access point a packet having a voice flag that was set to indicate the voice-capable status of terminal T.
  • the terminal may have transmitted the packet in an initial communications exchange between the terminal and access point.
  • Terminal T may be a terminal that is one of a plurality of terminals that are associated with the access point.
  • the packets in queue 128 may have been received after the initial exchange between the access point and terminal T.
  • the packets in queue 128 were prioritized based on the voice-capable status of terminal T (e.g., UDP packets are prioritized higher than TCP packets).
  • an application may assign a priority to each packet in queue 128 .
  • the packets are then transmitted based on the assigned priorities and an acknowledgment packet is transmitted by terminal T and for each packet that is properly received by terminal T.
  • Received packets in queue 128 are prioritized and transmitted in the following sequence: packet no. 4 (MNGT), packet no. 1 (UDP), packet no. 3 (UDP), and packet no. 2 (TCP).
  • MNGT packet no. 4
  • UDP packet no. 1
  • UDP packet no. 3
  • TCP packet no. 2
  • a transmitter such as an access point or a terminal may determine whether a packet that is to be transmitted is for providing voice communications.
  • the transmitter may determine whether the carrier channel is idle for a predetermined duration T.sub.o (i.e., the carrier channel is available). The determination may be made using carrier sensing equipment that is implemented in the transmitter.
  • the transmitter may determine whether the carrier channel is idle for a duration T.sub.r that is less than duration T.sub.o (e.g., what is the duration that is actually used) when the transmitter determines that the packet that is to be transmitted is for voice communications.
  • the transmitter may transmit the packet when the transmitter determines that the carrier channel has been idle for an appropriate duration of time (i.e., T.sub.o or T.sub.r).
  • a contention window may specify the duration which a transmitter is to sense for a carrier channel frequency to determine whether the channel is idle (e.g., available for carrying transmissions).
  • FIG. 9 b shows a graph that illustrates different contention windows for voice and other data.
  • Transmitted packets may be acknowledged by each recipient by the recipient transmitting an acknowledgment packet in response to the intended recipient receiving the transmitted packet.
  • the transmitter may then discard the transmitted packet that has been acknowledged and/or commence transmitting packets which have not yet been transmitted. Packets that have not yet been acknowledged may be retransmitted (e.g., the packets remain in queue for transmission). Illustrative steps involved in retransmitting packets for use in a wireless LAN (e.g., wireless LAN 20 of FIG. 1 ) are shown in FIG. 10 a .
  • a packet that is directed to a particular terminal may be transmitted.
  • the transmitter may determine whether an acknowledge packet has been received.
  • the transmitter may transmit the next packet (e.g., the next highest priority packet) for that terminal after an acknowledgment has been received for the transmitted packet.
  • the transmitter may continue to retransmit the packet until the packet is acknowledged or until the number of times the packet is transmitted reaches a retry threshold.
  • Step 146 may include the step of determining the retry threshold based on whether the packet is for voice communications.
  • the retry threshold for voice packets may be preset to be lower than the retry threshold for other packets.
  • Illustrative packet transmission rounds 148 , 150 , 152 and 162 of FIG. 10 b may be implemented based on the illustrative steps of FIG. 10 a .
  • round 148 the first round
  • packet A is transmitted by access point 154 to terminal T 2 and an acknowledgment is not transmitted in reply by terminal T 2 .
  • round 150 the second round
  • packet A is retransmitted and an acknowledgment is again not received from terminal T 2 .
  • Packet A continues to be transmitted in the subsequent rounds for a total of n rounds where in each round an acknowledgment for packet A has not received.
  • the value of n may be a retry threshold and the valve may be different for voice and data packets.
  • retransmissions of packet A may be discontinued and a different packet (e.g., the next highest priority packet for terminal T 2 ) may be transmitted in the subsequent round, round 162 .
  • a transmitter may transmit a packet for a particular terminal.
  • the transmitter may determine whether an acknowledgment has been received in reply to the transmitted packet.
  • the transmitter may transmit the next packet for that terminal when the transmitter has determined that an acknowledgment for the transmitted packet has been received.
  • step 170 when it is determined that an acknowledgment has not been received, the packet is retransmitted until it is acknowledged or until an initial retry threshold has been reached (e.g., the packet has been transmitted k times). If desired, step 170 may include determining how many times to retry transmission (step 170 a ) (e.g., based on whether the packet is for voice communications). When the initial retry threshold is reached, further retry transmissions are halted until after a frequency hop in modulation (step 172 ). At 174 , the packet may be further retransmitted until it is acknowledged or until a total retry threshold has been reached. If desired, step 174 may include determining how many total times to retry the transmission of the packet (e.g., based on whether the packet is for voice communications).
  • Illustrative transmission rounds 176 , 178 , 180 and 182 of FIG. 11 b may be implemented based on the illustrative steps of FIG. 11 a .
  • access point 184 may transmit packet A to terminal T 2 .
  • access point 184 may again transmit packet A to terminal T 2 when an acknowledgment packet was not received for packet A in the previous round.
  • access point 184 continues to retransmit packet A while a responsive acknowledgment has not been received and until packet A has been transmitted a particular number of times k. When packet A has been transmitted k times, any further retransmissions are halted until a hop in the frequency that is being used for spread spectrum communications.
  • round 182 after a frequency hop, access point 182 resumes transmitting packets to terminal T 2 .
  • Retransmission of an unacknowledged packet may be preempted by the reception of a packet that has a higher priority than the unacknowledged packet.
  • Illustrative steps involved in transmitting a highest priority packet for each terminal in a wireless local area network are shown in FIG. 12 a .
  • received packets may be prioritized.
  • the highest priority packet for each terminal may be selected.
  • one round of packets e.g., the selected packets
  • the transmitter determines whether an acknowledgment has been received for each transmitted packet.
  • new packets are received for transmission.
  • the packets that are to be transmitted are prioritized.
  • the highest priority packet for each terminal is selected.
  • another round of packets is transmitted.
  • Illustrative queues 206 , 208 , 210 , 212 and 214 of FIG. 12 b may be implemented based on the illustrative steps of FIG. 12 a .
  • Queue 206 and 208 may be queues that include prioritized packets that access point 216 is to transmit to terminals T 1 and T 2 , respectively.
  • the access point may transmit packets nos. 1 and 6 which are the highest priority packets for T 1 and T 2 , respectively.
  • packet no packet no.
  • UDP unacknowledged by terminal T 2 .
  • packet no. 6 is reinserted into queue 208 for terminal T 2 .
  • Additional packets 210 may be received by the access point 216 for transmission to terminals T 1 and T 2 before the next round of packets are to be transmitted.
  • Queues 206 a and 206 b may be implemented when the additional packets are prioritized.
  • Queues 206 a and 206 b include prioritized packets that are to be transmitted to terminals T 1 and T 2 , respectively.
  • packet no. 6 for terminal T 2 was unacknowledged and reinserted into queue 208 a .
  • New management packet 13 for terminal T 2 has been received after the first round and has been prioritized to have a higher priority than packet no. 6 .
  • packet no. 13 is transmitted over unacknowledged packet no. 6 .
  • retransmission of packet no. 6 is preempted by transmission of higher priority packet no. 13 .
  • Retransmission may commence in a future round when packet no. 6 is the highest priority packet that is pending to be transmitted for terminal T 2 .
  • a wireless LAN system and methods are provided that effectively carry mixed traffic communications. Greater priority is given to the transmission of packets for voice communications than for data communications while preventing transmission of data communications from being substantially blocked. Moreover, the system and methods, while meeting the complex demands of a mixed communications traffic environment, may still be implemented without substantial increases in structure, complexity, cost, processing delay, etc. over known wireless LAN systems and methods.

Abstract

A wireless local area network that carries mixed traffic of voice and data communications may be provided. The wireless local area network may include an access point and a plurality of remote terminals that are associated with the access point. The access point may be operably coupled to a wireline network. The access point may receive voice and other communications packets from the remote terminals and the wireline network. Some of the packets may be for transmission to the remote terminals. The access point manages which packets to transmit and when to transmit packets. The access point may manage traffic to maintain a fair distribution of packets and to give priority to voice communications over other communications.

Description

    BACKGROUND
  • This invention relates to wireless local area networks (“LANs”), and more particularly, to wireless local area networks that carry a mixed traffic of voice and data.
  • Wireless LANs are typically used in applications that involve mobile computers, in applications where wireline installation is not feasible, etc. Such applications include warehouse inventory tracking, portable point of sale, shipping and receiving, package tracking, etc.
  • The IEEE 802.11 communications standard has been used by some vendors to provide interoperability between wireless LAN equipment. The 802.11 standard specifies a protocol in which information is transmitted in packets. The standard specifies features such as packet size, packet content information, data rates, roaming, etc. The primary type of information that was initially transmitted in systems that were designed to the 802.11 standard as published was information such as barcode information, point of sale information, package tracking information, etc. In such known systems, several remote terminals may be in communications with a single access point to receive and transmit information such as bar code information, point of sale information, package tracking information, etc. The standard as published specifies a communications medium that is shared by transmitters (e.g., an access point and one or more remote terminals).
  • The standard further specifies that packet size may vary. A remote terminal that has a relatively large packet to transmit may need to occupy the shared communications medium for a longer period than a remote terminal that has a relatively short packet to transmit. Until recently, delays in communicating packets have typically been non-critical to providing communications at least partly because of the type of information that has been transmitted in such systems. Information such as bar code information, package tracking information, etc. typically remains valid until a next incremental event occurs (e.g., until bar code information has changed, until a package is tracked to a next point in route, etc.). In addition, such information does not generally effect system communications if delivered with some delay.
  • In some known systems, packets are simply transmitted in the order in which they have been received for transmission. In these known systems, a packet that is transmitted without being properly acknowledged by its intended recipient is repeated for a predetermined number of times while transmission of other remaining packets is delayed. After retransmitting a packet for a predetermined number of times without receiving a proper acknowledgment, the transmitter may proceed to transmit the remaining packets.
  • The demand for providing mixed voice and data traffic in wireless LAN systems has been increasing over recent years. Currently, the 802.11 standard does not provide specifications for providing voice communications. Information for providing voice communications is generally much more time critical than other information such as bar code information, package tracking information, etc. Communications for providing voice communications may require a greater volume of information to be carried by the system than when the system is providing communications for information that has typically been carried by wireless LANs. Moreover, the quality of voice communications is dependent on the rate in which information is exchanged. In data communications such as in communications for package tracking, the rate in which information is exchanged is non-critical because the quality of such communications is typically not a factor in evaluating the effectiveness of such communications.
  • Some known wireless LANs carry voice signals as part of the communications traffic but these systems are deficient in effectively meeting such complex communications demands as discussed above. Moreover, there may be a need to meet such demands with existing systems without substantially increasing system complexity, structure, design, cost, etc.
  • SUMMARY OF THE INVENTION
  • In accordance with the principles of the present invention, a mixed traffic voice and data communications transmitter and network may be provided. The communications network may be a wireless local area network that uses packet based communications. The communications network may include at least one access point that receives voice and other communications for transmission to terminals that are associated with the access point.
  • To manage the transmission of packets, a transmitter may prioritize packets. Prioritization may be based on when each packet has been received, whether the packets contain voice communications, whether the packets contain network-management communications, whether the packets contain data communications (e.g., communications other than for voice or network management), whether the packet is directed to a voice-capable unit, whether a packet was transmitted using a particular communications protocol, etc.
  • A transmitter, such as an access point, may prioritize packets for transmission based on to which receiver terminal the packets have been addressed. Packets may be separated into queues with each queue storing the packets that have been received for transmission to a particular terminal. Packets may be further prioritized within each queue.
  • Prioritized packets may be transmitted in a sequence that allows a fair opportunity to each terminal to receive the same number of packets. For example, packets may be transmitted in rounds. In each round, the highest priority packet for each terminal may be transmitted (e.g., in a one packet per round per terminal fashion). In each round, an equal number of packets may be transmitted to each terminal (e.g., one per packet).
  • For each transmitted packet, an acknowledgment (e.g., an acknowledge packet) from a receiving terminal may be required before the transmitter discards the transmitted packet or moves onto transmitting the next packet for that terminal. A transmitter may repeatedly transmit a packet until it is acknowledged or until a retry threshold (e.g., a total number of times that a packet is to be transmitted) has been reached. The retry threshold may be determined based on whether the packet that is being retransmitted is for voice communications. The retry threshold for voice communications may be lower than for other communications. In communications networks that use frequency hopping spread spectrum communications, a packet may be retransmitted when the number of times the packet has been transmitted reaches an initial retry threshold. When the initial retry threshold is reached without an acknowledgment being received, retransmission may be discontinued until after a frequency hop in modulation. Thereafter, retransmissions may resume until an acknowledgment is received or until a total retry threshold has been reached. The initial and total retry thresholds may vary based on whether the packet that is being retransmitted is for voice communications. New packets that are received and prioritized may have a higher priority than an unacknowledged packet.
  • New packets that are received and prioritized may have a higher priority than unacknowledged packets. Retransmission of an unacknowledged packet may be preempted when a packet with a priority that is higher than the packet being retransmitted is received. A transmitter may transmit a newly received packet for a particular terminal over other earlier received packets for that same terminal when the newly received packet is determined to have a higher priority than the other packets. An unacknowledged packet may then be retransmitted in a later round.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • Further features of the invention, its nature and various advantages will be more apparent from the following detailed description, taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout, and in which:
  • FIG. 1 is a diagram of an illustrative communications network that includes an illustrative wireless local area network in accordance with the present invention;
  • FIG. 2 a is a flow chart of illustrative steps involved in managing packet traffic for use in a transmitter in accordance with the present invention;
  • FIG. 2 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 2 a in accordance with the present invention;
  • FIG. 3 a is a flow chart of illustrative steps involved in transmitting packets in accordance with the present invention;
  • FIG. 3 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 3 a in accordance with the present invention;
  • FIG. 4 a is a flow chart of illustrative steps involved in managing packet traffic based on which packets are for voice in accordance with the present invention;
  • FIG. 4 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 4 a in accordance with the present invention;
  • FIG. 5 a is a flow chart of illustrative steps involved in managing packet traffic based on which packets are for network management in accordance with the present invention;
  • FIG. 5 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 5 a in accordance with the present invention;
  • FIG. 6 a is a flow chart of illustrative steps involved in managing packet traffic with multiple levels of priority in accordance with the present invention;
  • FIG. 6 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 6 a in accordance with the present invention;
  • FIG. 7 a is a flow chart of illustrative steps that are involved in managing packet traffic based on which terminals are voice capable in accordance with the present invention;
  • FIG. 7 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 7 a in accordance with the present invention;
  • FIG. 8 a is a flow chart of illustrative steps involved in managing traffic based on determining which terminals are voice capable in accordance with the present invention;
  • FIG. 8 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 8 a in accordance with the present invention;
  • FIG. 9 a is a flow chart of illustrative steps involved in using variable contention windows in accordance with the present invention;
  • FIG. 9 b is a diagram of illustrative durations for contention windows in accordance with the present invention;
  • FIG. 10 a is a flow chart of illustrative steps involved in transmitting packets in accordance with the present invention;
  • FIG. 10 b is a flow chart of illustrative packet-based communications that are based on the illustrative steps of FIG. 10 a in accordance with the present invention;
  • FIG. 11 a is a flow chart of illustrative steps involved in packet-based communications using frequency hopping in accordance with the present invention;
  • FIG. 11 b is a flow chart of illustrative packet-based communications that are based on the illustrative steps of FIG. 11 a in accordance with the present invention;
  • FIG. 12 a is a flow chart of illustrative steps involved in incrementally transmitting packets in accordance with the present invention; and
  • FIG. 12 b is a diagram of illustrative queues that may be implemented based on the illustrative steps of FIG. 12 a in accordance with the present invention.
  • DETAILED DESCRIPTION OF THE INVENTION
  • The present invention improves mixed traffic voice communications for wireless local area networks (“LANs”) by substantially meeting the communications demands that have been mentioned above. Packets that are to be transmitted in a wireless LAN over a half-duplex communication medium are transmitted in order of priority. Priority may be determined based on at least whether a particular packet is for providing voice communications. One technique for determining whether a packet is for voice communications is to determine whether the intended recipient of the packet has been identified to be voice-capable and further determining whether the packet was received for transmission using a particular communications protocol (e.g., a protocol typically used to send voice communications). Other techniques for prioritizing packets for transmission and for determining which packets are for voice communications are discussed below.
  • Giving high priority to voice communications may block other non-voice communications packets from being transmitted. Blocking may be substantially prevented by providing for fair distribution of packets. Packets may be distributed fairly by transmitting packets in rounds where in each round one packet (e.g., the highest priority packet) is transmitted for every receiver (e.g., a remote terminal). In the case of a packet that is transmitted without being acknowledged by its intended recipient, the packet may be retransmitted in the next round of transmissions except for when another packet with a higher priority than the unacknowledged packet has been recently received for transmission to the same terminal. The recently received packet with a higher priority will be transmitted before the unacknowledged packet is transmitted again. The number of times a packet is retransmitted may be determined based on whether the packet is for providing voice communications. Priority may also be given to voice communications by using techniques that are discussed below that give greater access to the communications medium to transmitters that are about to transmit packets that are for voice communications.
  • With reference to FIG. 1, wireless local area network (“LAN”) 20 may include a plurality of cells 22. For brevity and clarity, wireless LAN 20 is illustrated and discussed primarily in the context of a LAN having one cell 22. Cell 22 may include an access point 24 (which is sometimes referred to as a wireless local bridge). Cell 22 may include remote terminals 26. Each terminal 26 may be a mobile, portable, or stationary terminal. Each terminal 26 may be a desktop workstation, laptop computer, palm top computer, handheld personal computer, pen-based computer, personal digital assistant, handheld scanner, data collector, handheld printer, etc. Each terminal 26 may include wireless-network-interface resources that are configured to provide two-way radio or infrared signal communications. Such resources may include an interface card (or an external modem), a software driver, and an antenna. Other suitable resources may also be used, but for clarity and brevity, the wireless network interface resources will be discussed primarily in the context of an interface card, a software driver, and an antenna. The interface card may have been configured to use a standard computer-bus interface (e.g., ISA, PCMCIA, etc.) or standard computer port (e.g., Rs232, RS422, etc.) to provide convenient access to terminal equipment.
  • A network-operating-system may be implemented on each terminal 26. In each terminal 26, the interface card may be coupled to the network-operating-system application using the software driver. The interface card for each remote terminal 26 may be a network-communications interface. The network interface card for each terminal 26 are typically implemented to use a carrier sense access protocol and to modulate communications signals with a spreading sequence.
  • Access point 24 may be an interface for communicating between wireless network 20 and a wireline network. Access point 24 may be configured to provide a communications gateway between terminals 26 that are in cell 22 and between a wireline network and the terminals 26. Access point 24 may include a resource(s) (e.g., software, hardware, or a combination thereof) that is configured to connect the access point to a wireline network (e.g., on ethernet network, a token ring network, etc.). Access point 24 is typically configured to convert signals between wireline and wireless communications mediums. The conversion may allow the access point to pass communication information between the wireline network and wireless remote terminals 26.
  • Access points are typically provided with sufficient processing, hardware, software, etc. to operate in compliance with the IEEE 802.11 (e.g., to provide 802.11 roaming, standard 802.11 data rates, etc.) and to provide additional features that are developed by a vendor. Access point 24 may be implemented using a personal computer (e.g., a Power PC, an IBM compatible computer), server, workstation, etc., having an appropriate operating system, wireless-network-interface resources, wireline-network-interface resources, network-operating-system applications, etc.
  • Access point 24 and remote terminals 26 may be configured to communicate using spread spectrum modulation techniques (e.g., direct sequence spread spectrum modulation, frequency hopping spread spectrum modulation, etc.).
  • The IEEE 802.11 standard specifies the format and content of communications packets. Communications packets that may also be referred to as frames may be of variable size with the size of each packet being identified in packet header information. In some embodiments, the body of each packet may vary from 0 to 2312 octets.
  • In operation, initially when one of the terminals 26 is powered, that terminal 26 may seek to join cell 22 by associating with access point 24. Remote terminal 26 may become associated with access point 24 after a preliminary exchange of communications between access point 24 and terminal 26. A plurality of terminals 26 may be associated with each access point 24. Each terminal 26 may have different communications capabilities and requirements. Access point 24 may manage the communications traffic between terminals 26 and the wireline network. Access point 24 may manage the communications traffic by controlling when packets are transmitted to each remote terminal 26 in cell 22. The communications traffic in cell 22 may include data packets (e.g., signals that carry packets to provide data communications), voice packets (e.g., signals that carry packets to provide voice communications), real-time packets (e.g., signals that carry packets to provide real-time communications such as multimedia or voice communications), management packets (e.g., signals that carry packets to provide network management communications), etc.
  • The wireline network that is coupled to access point 24 may include equipment 23 that is configured to implement the wireline network. The wireline network may be coupled to an external network (e.g., PBX, PSTN, Internet, etc.).
  • Access point 24 may manage communications traffic by prioritizing packets that are to be transmitted to the remote terminals 26 that are associated with access point 24. Illustrative steps involved in managing communications traffic for use in an access point such as access point 24 of FIG. 1 are shown in FIG. 2 a. At step 40, an access point may receive signals carrying packets that are to be transmitted to remote terminals (e.g., packets that are addressed to individual terminals 26 in cell 22 of FIG. 1). At step 42, the access point may prioritize the received packets for transmission. An access point may prioritize received packets to determine to which remote terminal to transmit a packet next and to determine which one of the packets that are to be transmitted to that remote terminal will be the packet to be transmitted next. Prioritization may be performed in intervals as packets are received by the access point. For example, prioritization may be performed at regular periodic intervals. Each packet may be prioritized based on time of reception, packet content, packet address information, message protocol, fairness to each terminal, etc.
  • For clarity, the management of packet communications traffic is primarily discussed in the context of queues. Techniques other than the use of queues may also be used for managing packet communications traffic. Illustrative queues 44, 46, 48, 50 and 52 of FIG. 2 b may be provided based on the illustrative steps of FIG. 2 a. Queue 44 includes illustrative packets in the order in which they were received by an access point. The packets in queue 44 may have been received from remote terminals that are associated with the access point or from a wireline network. The packets in queue 44 are packets that are directed to four terminals T1, T2, T3 and T4. Queues 46, 48, 50 and 52 may include packets from queue 44 when the packets have been prioritized by the access point. Each respective queue 46, 48, 50 and 52 is a queue that is associated with a respective terminal T1, T2, T3, and T4. Within each queue 46, 48, 50 and 52 packets may have been prioritized based on when the packets were received.
  • Each packet illustrated in queue 44 has a terminal address and a packet number. The packet number is used here for illustrative purposes to show the order in which packets were received by the access point. In queues 46, 48, 50 and 52, packets with lower packet numbers are higher in transmission priority because they were received first.
  • Packets may be transmitted based on priority. Illustrative steps involved in transmitting packets are shown in FIG. 3 a. At step 54, an access point may prioritize packets for transmission. At step 56, the prioritized packets may be distributed by transmitting packets based on priority, based on fairness, based on fairness and priority, based on fairness per terminal, based on a one packet per terminal transmission sequence, etc. If desired, fairness may be determined as part of step 54 when the access point prioritizes packets.
  • Illustrative queues 58, 60, 62, 64 and 66 of FIG. 3 b may be provided based on the illustrative steps of FIG. 3 a. Queues 58, 60, 62 and 64 may each be associated with a respective terminal (T1, T2, T3, and T4). The packets may have been received by an access point for transmission to terminals (T1, T2, T3, and T4). In each queue, the packets may have been prioritized based on time of reception. To achieve fairness, the access point may transmit packets in rounds. In each round, the access point may transmit the same number of packets (e.g., one packet) to each terminal.
  • Queue 66 includes the packets from queues 58, 60, 62 and 64 in the sequence in which the packets are to be transmitted. The sequence may be divided into rounds with each round including one packet per terminal. As shown, the first and second rounds each have four packets, one for each terminal that is associated with the access point. The third round includes three packets because there are no more packets that are pending to be transmitted to T3 in queue 62 after the first two rounds were successfully transmitted.
  • An access point may select and transmit packets for each terminal in each round in the order in which that the packets for that terminal were received by the access point. With continued reference to FIG. 3 b, in the first round, the access point transmits packets nos. 2, 3, 6 and 1 that are each the first packet in queues 58, 60, 62, and 64, respectively. In the second round, the access point transmits packets nos. 4, 8, 7 and 5 that are each the next packet that was received for each terminal T1, T2, T3 and T4, respectively. In each round, one packet from each queue is transmitted without having competition between the queues for a position in the round.
  • The illustrative packets in FIG. 3 b (and in the other FIGS.) are variable size packets. The packets are illustrated as fixed length packets to simplify the figures.
  • The access point may prioritize packets based on which packets are for voice communications. Illustrative steps involved in prioritizing packets based on which packets are for voice communication are shown in FIG. 4 a. At step 68, an access point may determine which of the packets that are to be transmitted are for voice communications.
  • Packets that are for voice communications may be packets that carry digitized voice communications. As discussed above, voice communications typically have stricter transmission requirements than other communications such as inventory data, point of sale information, etc. The access point may determine which packet is for voice based on a message flag in the packet, based on the packet being addressed to a voice-capable terminal, based on the messaging protocol (discussed further below), etc. At step 70, packets may be prioritized based on determining which packets are for voice. Packets for voice communications may be prioritized higher than other packets.
  • Illustrative queues 72, 74 and 76 of FIG. 4 b may be provided based on the illustrative steps of FIG. 4 a. Queue 72 may include packets that have been received by an access point for transmission to terminals T1 and T2. Queue 72 includes packets that are to be transmitted to provide voice communications (packets nos. 1, 4 and 6). Packets that are for voice communications are prioritized higher than other packets in queues 74 and 76 so that these voice packets are transmitted before other packets. Queue 74 for terminal T1 includes voice packet no. 6 that is prioritized higher than packets nos. 3 and 5 which were received before packet no. 6. Queue 76 for terminal T2 includes voice packets nos. 1 and 4 that are prioritized higher than packets nos. 2 and 7 that are for other communications. Within each queue, voice packets are prioritized to be transmitted before other packets. All packets in a queue are further prioritized for transmission based when each packet was received by the access point.
  • An access point may prioritize packets based on network management requirements. Illustrative steps involved in prioritizing packets based on network management requirements are shown in FIG. 5 a. At step 78, the access point may determine which ones of the packets are to be transmitted to manage network operations. Packets are determined to be for network management based on a message flag, message length, etc. At step 80, packets may be prioritized based on which packets are for network management.
  • Illustrative queues 82, 84 and 86 of FIG. 5 b may be provided based on the illustrative steps of FIG. 5 a. Queue 82 of received packets may include packets nos. 1, 4 and 6 that are to be transmitted to provide network management. Management packets may be prioritized higher than other packets to protect the integrity of network operations. Queues 84 and 86 may be implemented for terminals T1 and T2, respectively. Management packets nos. 1 and 4 are prioritized higher (i.e., positioned at top of the queue) than the other packet in queue 84 for T1 and management packet no. 6 is prioritized higher than the other packets in queue 86 for T2. The higher priority packets in each queue are to be transmitted before the lower priority packets in the queue.
  • In a wireless local area network, packet traffic may be managed using different levels of priority. Illustrative steps involved in prioritizing packets with different levels of priority are shown in FIG. 6 a. At step 88, an access point may determine which packets are for providing voice, network management, or other communications. At step 90, packets that are for managing network operations are prioritized highest. At step 92, packets that are for voice communications are prioritized second highest. At step 94, packets that are for other communications are prioritized third highest.
  • Illustrative queues 96, 98, 100 and 102 of FIG. 6 b may be provided based on the illustrative steps of FIG. 6 a. Queue 96 may include received packets that include voice, management and other communications packets that are to be transmitted for terminals T1, T2 and T3. Queues 98, 100 and 102 may be implemented for terminals T1, T2 and T3, respectively. In queues 98, 100 and 102, management packets are prioritized highest (i.e., higher than voice and other communications packets), voice packets are prioritized second highest, and other communications packets are prioritized third highest. Priority between packets that are for the same type of communications may be based on time of reception. Packets may be transmitted by the access point in the order of packet priority for each remote terminal.
  • Some wireless LANs use the seven-layer Open System Interconnect (OSI) reference model developed by the International Standard Organization (ISO). OSI specifies a complete set of network functions, grouped into seven layers. The seven layers are the physical layer (layer 1), data link layer (layer 2), network layer (layer 3), transport layer (layer 4), session layer (layer 5), presentation layer (layer 6) and application layer (layer 7). The network functions are structured so that each OSI layer is supported by the layers below it.
  • The transport layer establishes and maintains communications between applications on different computers. Communications protocols such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) operate at the transport layer. TCP provides full-duplex connection-oriented services (i.e., maintains a virtual communications connection between end users) while UDP provides connection-less-oriented services (i.e., provides communications between end users without maintaining an open connection). The communications protocol that is typically used for voice communications in the network layer is UDP.
  • Illustrative steps involved in transmitting packets for use in a wireless local area network (e.g., wireless local area network 20 of FIG. 1) that is configured to implement the OSI transport layer are shown in FIG. 7 a. At step 104, an access point may determine which terminals are voice capable. The access point may determine which terminals are voice capable based on a message flag in a packet, on pre-assigned addresses for voice-capable terminals, etc. At step 106, the access point may receive packets for transmission to the terminals. Step 106 may be performed before, after, or during step 104.
  • At 108, the access point may prioritize packets. Prioritization may be based on a plurality of factors. Prioritization may be based on to which terminal a packet is directed, based on the communications protocol of the packet, based on whether the packet is for network management, and further based on time of reception. At step 110, packets may be transmitted. Packets may be transmitted based on how the packets were prioritized and based on fairness (e.g., maintains fairness by maintaining an equal distribution of packets among the remote terminals).
  • Illustrative queues 112, 114, 116, 118 and 120 of FIG. 7 b may be implemented based on the illustrative steps of FIG. 7 a. Queue 112 may be a queue of received packets that are positioned in the queue 112 in the order in which they were received by an access point. Terminals T1, T2 and T3 may have already been associated with the access point when the packets were received by the access point. Queues 114, 116 and 118 may be implemented for terminals T1, T2 and T3, respectively, when the received packets are prioritized. The access point may have determined that terminal T1 is a voice-capable terminal before the packets in queue 112 were received.
  • Packets that are to be transmitted to manage the wireless network may have been prioritized highest. Queue 112 includes two management packets, packet no. 1 which is directed to terminal T1 (e.g., addressed to terminal T1) and packet no. 9 which is directed to terminal T3. Queue 114 for terminal T1 is implemented to have packet no. 1 have the highest priority in queue 114 and queue 119 for terminal T3 is implemented to have packet no. 9 have the highest priority in queue 119.
  • Packets that are to be transmitted to provide voice communications may have been prioritized second highest. The communications protocols of the OSI transport layer handle packets without determining whether the packets are for voice communications. Some networks that are implemented using the OSI transport layer use UDP for providing voice communications. An access point may determine which packets are for voice based on the communications protocol of the packets (e.g., UDP) and based on whether the packet is directed to a voice-capable terminal. Communications protocols operating in the transport layer (i.e., TCP and UDP) use Internet Protocol (IP) services in the network layer to deliver messages between source (e.g., an external network) and destination (e.g., wireless LAN 20 of FIG. 1) systems. IP packets include a protocol field that indicates that the enclosed packets are for which protocol in the Transport Layer (e.g., UDP, TCP, etc.).
  • Packets may be received by an access point from a half-duplex communications medium (e.g., a radio frequency channel) that is shared between the access point and remote terminals on which remote terminals communicate with the access point and received from another communications medium on which a wireline network communicates with the access point. Packets may have been transmitted to the access point using Internet Protocol (e.g., using IP packet formats) for Network Layer communications and using UDP, TCP, etc. (e.g., using UDP packet formats) for Transport Layer communications. Accordingly, packets that are received by the access point from the remote terminals may already be in conformance with the communications requirements for IP and UDP, TCP, etc. When necessary, the access point may configure packets to conform to the 802.11 standard (e.g., when two remote terminals in the wireless LAN are communicating).
  • The access point may read the protocol field of received IP packets to determine the Transport Layer communications protocol of received packet. Packets which are to be handled using UDP and which are directed to a voice-capable terminal may be determined by the access point to contain voice communications. The access point may have determined earlier which terminals are voice-capable through an earlier exchange with the terminals. The earlier exchange may occur when a remote terminal initially seeks to establish communications with (e.g., be associated with) an access point. If desired, the access point may have been programmed with information related to the capabilities of each terminal.
  • With reference again to FIG. 7 b, queue 114 for voice-capable terminal T1 includes packet no. 7 (UDP) and packet no. 10 (UDP) which are both prioritized higher than packet no. 3 that was received before them. In queues 116 and 118, UDP packets are not prioritized higher than TCP packets since the access point has not determined that T2 and T3 are voice-capable. In queues 116 and 118, management packets (if any) are prioritized highest with all other packets being prioritized second highest.
  • Queue 120 includes the packets in the order in which they are to be transmitted (i.e., the transmission sequence). Packets may be transmitted in one-packet-per-terminal rounds with the highest priority packet for each terminal being transmitted in each round. Such transmission techniques allow for the quick delivery of voice communications without substantially increasing the complexity, cost, structure, or design of network equipment.
  • Queues 114, 116 and 118 may have been configured to be of equal size. Queues of equal size may prevent the situation in which a large number of packets for one terminal occupies most of the storage space of the access point. Such a situation may block new packets that are received by the access point to be stored due to insufficient storage space. The size of such equal sized queues may be determined based on system limitations. For illustrative purposes, queues 114, 116 and 118 are each shown to be capable of storing only four packets.
  • Illustrative steps involved in prioritizing packets based on a terminal having a voice-capable status are shown in FIG. 8 a. At step 122, a terminal may transmit a packet that includes a voice flag to an access point. The voice flag may be set to indicate that the terminal is voice-capable. At step 123, the access point may determine the status of the terminal by receiving the packet and reading the voice flag of the packet. At step 124, the access point may store information indicating the voice-capable status of the terminal. At step 126, the access point may prioritize packets based on the terminal having a voice-capable status.
  • Queue 128 and packet flow chart 130 of FIG. 8 b may be implemented based on the illustrative steps of FIG. 8 a. Chart 130 indicates that terminal T transmitted to an access point a packet having a voice flag that was set to indicate the voice-capable status of terminal T. The terminal may have transmitted the packet in an initial communications exchange between the terminal and access point. Terminal T may be a terminal that is one of a plurality of terminals that are associated with the access point.
  • The packets in queue 128 may have been received after the initial exchange between the access point and terminal T. The packets in queue 128 were prioritized based on the voice-capable status of terminal T (e.g., UDP packets are prioritized higher than TCP packets). Within the access point, an application may assign a priority to each packet in queue 128. The packets are then transmitted based on the assigned priorities and an acknowledgment packet is transmitted by terminal T and for each packet that is properly received by terminal T. Received packets in queue 128 are prioritized and transmitted in the following sequence: packet no. 4 (MNGT), packet no. 1 (UDP), packet no. 3 (UDP), and packet no. 2 (TCP).
  • In wireless LANs that use carrier-sense multiple access with collision avoidance (CSMA/CA) greater access to the communications bandwidth may be provided for transmitting voice communications than for transmitting other communications. Illustrative steps involved in transmitting voice packets in a CSMA/CA system are shown in FIG. 9 a. At step 132, a transmitter (such as an access point or a terminal) may determine whether a packet that is to be transmitted is for providing voice communications. At step 136, the transmitter may determine whether the carrier channel is idle for a predetermined duration T.sub.o (i.e., the carrier channel is available). The determination may be made using carrier sensing equipment that is implemented in the transmitter. At step 134, the transmitter may determine whether the carrier channel is idle for a duration T.sub.r that is less than duration T.sub.o (e.g., what is the duration that is actually used) when the transmitter determines that the packet that is to be transmitted is for voice communications. At step 138, the transmitter may transmit the packet when the transmitter determines that the carrier channel has been idle for an appropriate duration of time (i.e., T.sub.o or T.sub.r). A contention window may specify the duration which a transmitter is to sense for a carrier channel frequency to determine whether the channel is idle (e.g., available for carrying transmissions). FIG. 9 b shows a graph that illustrates different contention windows for voice and other data.
  • Transmitted packets may be acknowledged by each recipient by the recipient transmitting an acknowledgment packet in response to the intended recipient receiving the transmitted packet. The transmitter may then discard the transmitted packet that has been acknowledged and/or commence transmitting packets which have not yet been transmitted. Packets that have not yet been acknowledged may be retransmitted (e.g., the packets remain in queue for transmission). Illustrative steps involved in retransmitting packets for use in a wireless LAN (e.g., wireless LAN 20 of FIG. 1) are shown in FIG. 10 a. At step 140, a packet that is directed to a particular terminal may be transmitted. At step 142, the transmitter may determine whether an acknowledge packet has been received. At step 144, the transmitter may transmit the next packet (e.g., the next highest priority packet) for that terminal after an acknowledgment has been received for the transmitted packet. At step 146, when an acknowledgment has not been received for the transmitted packet, the transmitter may continue to retransmit the packet until the packet is acknowledged or until the number of times the packet is transmitted reaches a retry threshold. Step 146 may include the step of determining the retry threshold based on whether the packet is for voice communications. The retry threshold for voice packets may be preset to be lower than the retry threshold for other packets.
  • Illustrative packet transmission rounds 148, 150, 152 and 162 of FIG. 10 b may be implemented based on the illustrative steps of FIG. 10 a. In round 148 (the first round), packet A is transmitted by access point 154 to terminal T2 and an acknowledgment is not transmitted in reply by terminal T2. In round 150 (the second round), packet A is retransmitted and an acknowledgment is again not received from terminal T2. Packet A continues to be transmitted in the subsequent rounds for a total of n rounds where in each round an acknowledgment for packet A has not received. The value of n may be a retry threshold and the valve may be different for voice and data packets. After the nth round 152, retransmissions of packet A may be discontinued and a different packet (e.g., the next highest priority packet for terminal T2) may be transmitted in the subsequent round, round 162.
  • Illustrative steps for retransmitting unacknowledged packets for use in a wireless LAN (e.g., wireless LAN 20 of FIG. 1) that is configured to use frequency hopping spread spectrum modulation are shown in FIG. 11 a. At step 104, a transmitter may transmit a packet for a particular terminal. At step 166, the transmitter may determine whether an acknowledgment has been received in reply to the transmitted packet. At step 168, the transmitter may transmit the next packet for that terminal when the transmitter has determined that an acknowledgment for the transmitted packet has been received. At step 170, when it is determined that an acknowledgment has not been received, the packet is retransmitted until it is acknowledged or until an initial retry threshold has been reached (e.g., the packet has been transmitted k times). If desired, step 170 may include determining how many times to retry transmission (step 170 a) (e.g., based on whether the packet is for voice communications). When the initial retry threshold is reached, further retry transmissions are halted until after a frequency hop in modulation (step 172). At 174, the packet may be further retransmitted until it is acknowledged or until a total retry threshold has been reached. If desired, step 174 may include determining how many total times to retry the transmission of the packet (e.g., based on whether the packet is for voice communications).
  • Illustrative transmission rounds 176, 178, 180 and 182 of FIG. 11 b may be implemented based on the illustrative steps of FIG. 11 a. In round 176, access point 184 may transmit packet A to terminal T2. In round 178, access point 184 may again transmit packet A to terminal T2 when an acknowledgment packet was not received for packet A in the previous round. In the following rounds, access point 184 continues to retransmit packet A while a responsive acknowledgment has not been received and until packet A has been transmitted a particular number of times k. When packet A has been transmitted k times, any further retransmissions are halted until a hop in the frequency that is being used for spread spectrum communications. In round 182 after a frequency hop, access point 182 resumes transmitting packets to terminal T2.
  • Retransmission of an unacknowledged packet may be preempted by the reception of a packet that has a higher priority than the unacknowledged packet. Illustrative steps involved in transmitting a highest priority packet for each terminal in a wireless local area network (e.g., wireless LAN of FIG. 1) are shown in FIG. 12 a. At step 190, received packets may be prioritized. At step 192, the highest priority packet for each terminal may be selected. At step 194, one round of packets (e.g., the selected packets) are transmitted. At step 196, the transmitter determines whether an acknowledgment has been received for each transmitted packet. At step 198, new packets are received for transmission. At step 200, the packets that are to be transmitted (i.e., the received packets and the unacknowledged packets) are prioritized. At step 202, the highest priority packet for each terminal is selected. At step 204, another round of packets is transmitted.
  • Illustrative queues 206, 208, 210, 212 and 214 of FIG. 12 b may be implemented based on the illustrative steps of FIG. 12 a. Queue 206 and 208 may be queues that include prioritized packets that access point 216 is to transmit to terminals T1 and T2, respectively. In a first round, when a half-duplex communications channel (e.g., a predetermined frequency band on which multiple devices communicate using CSMA and spread spectrum modulation) is determined to be idle, the access point may transmit packets nos. 1 and 6 which are the highest priority packets for T1 and T2, respectively. In the first round, packet no. 6 (UDP) that is transmitted to a voice-capable terminal T2 is unacknowledged by terminal T2. For the next round, packet no. 6 is reinserted into queue 208 for terminal T2. Additional packets 210 may be received by the access point 216 for transmission to terminals T1 and T2 before the next round of packets are to be transmitted. Queues 206 a and 206 b may be implemented when the additional packets are prioritized. Queues 206 a and 206 b include prioritized packets that are to be transmitted to terminals T1 and T2, respectively. In the previous round, packet no. 6 for terminal T2 was unacknowledged and reinserted into queue 208 a. New management packet 13 for terminal T2 has been received after the first round and has been prioritized to have a higher priority than packet no. 6. When access point 216 transmits the highest priority packet for terminal T2, packet no. 13 is transmitted over unacknowledged packet no. 6. Thus, retransmission of packet no. 6 is preempted by transmission of higher priority packet no. 13. Retransmission may commence in a future round when packet no. 6 is the highest priority packet that is pending to be transmitted for terminal T2.
  • Thus it is seen that a wireless LAN system and methods are provided that effectively carry mixed traffic communications. Greater priority is given to the transmission of packets for voice communications than for data communications while preventing transmission of data communications from being substantially blocked. Moreover, the system and methods, while meeting the complex demands of a mixed communications traffic environment, may still be implemented without substantial increases in structure, complexity, cost, processing delay, etc. over known wireless LAN systems and methods.
  • The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Claims (21)

1-37. (canceled)
38. A method, comprising:
selecting a packet for transmission, wherein the packet is one of at least two packet types;
determining whether a communications medium is busy;
selecting, when the communications medium is busy, one of a first time duration when the packet is a first type and a second time duration when the packet is a second type; and
transmitting the packet after one of the first time duration when the packet is the first type and the second time duration when the packet is the second type.
39. The method of claim 38, wherein the first time duration is one of a first range of durations and the second time duration is one of a second range of time durations.
40. The method of claim 39, wherein the first range of durations is exclusive of the second range of durations.
41. The method of claim 39, wherein the first range of durations is non-exclusive of the second range of durations.
42. The method of claim 38, wherein the type of the packet is based on a determined priority level of the packet.
43. A system, comprising:
a communication medium for communicating packets;
an access point to receive the packets from the communication medium;
a plurality of remote terminals to transmit packets to the communication medium, wherein, when one of the remote terminals has one of the packets for transmission, the one remote terminal determines whether the communication medium is busy, selects, when the communication medium is busy, one of a first time duration when the packet is a first type and a second time duration when the packet is a second type and transmits the packet after one of the first time duration when the packet is the first type and the second time duration when the packet is the second type.
44. The system of claim 43, wherein the first time duration is one of a first range of durations and the second time duration is one of a second range of time durations.
45. The system of claim 44, wherein the first range of durations is exclusive of the second range of durations.
46. The system of claim 44, wherein the first range of durations is non-exclusive of the second range of durations.
47. The system of claim 43, wherein the type of the packet is based on a determined priority level of the packet.
48. A communication device, comprising:
a transmission queue including a packet to be transmitted, the packet being one of at least two packet types;
a transmitter to determine whether a communication medium is busy, select, when the communication medium is busy, one of a first time duration when the packet is a first type and a second time duration when the packet is a second type and wirelessly transmit the packet after one of the first time duration when the packet is the first type and the second time duration when the packet is the second type.
49. The communication device of claim 48, wherein the communication device is one of a remote terminal and an access point.
50. The communication device of claim 48, wherein the first time duration is one of a first range of durations and the second time duration is one of a second range of time durations.
51. The communication device of claim 50, wherein the first range of durations is exclusive of the second range of durations.
52. The communication device of claim 50, wherein the first range of durations is non-exclusive of the second range of durations.
53. The communication device of claim 48, wherein the type of the packet is based on a determined priority level of the packet.
54. A method, comprising:
selecting a packet for transmission, wherein the packet is one of at least two packet types;
determining whether a communications medium is busy;
selecting, when the communications medium is busy, one of a first time duration when the packet is a first type and a second time duration when the packet is a second type; and
attempting to transmit the packet after one of the first time duration when the packet is the first type and the second time duration when the packet is the second type.
55. The method of claim 54, further comprising:
selecting, when the attempt to transmit is unsuccessful, a third time duration when the packet is the first type and a fourth time duration when the packet is the second type; and
attempting to transmit the packet after one of the third time duration when the packet is the first type and the fourth time duration when the packet is the second type.
56. The method of claim 55, wherein the first time duration is one of a first range of durations and the second time duration is one of a second range of time durations.
57. The method of claim 56, wherein the third time duration is one of the first range of durations and the fourth time duration is one of the second range of time durations.
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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050025105A1 (en) * 2003-07-30 2005-02-03 Seon-Soo Rue Apparatus and method for processing packets in wireless local area network access point
US20050165946A1 (en) * 2003-12-22 2005-07-28 Intel Corporation Bi-directional wireless LAN channel access
US20050281252A1 (en) * 2000-07-27 2005-12-22 Beach Robert E Voice and data wireless communications network and method
US20060198301A1 (en) * 2005-03-07 2006-09-07 Texas Instruments Incorporated Packet-level service differentiation for quality of service provisioning over wireless local area networks
US20060227782A1 (en) * 2005-04-08 2006-10-12 Bullman William R Method and apparatus for improved voice over Internet protocol (VoIP) transmission in a digital network
US20090168793A1 (en) * 2006-03-30 2009-07-02 David Fox Prioritising Data Transmission
US20090190566A1 (en) * 2008-01-30 2009-07-30 Samsung Electronics Co., Ltd. Method and apparatus of controlling access mode for communication system using shared or unlicensed band

Families Citing this family (211)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7387253B1 (en) 1996-09-03 2008-06-17 Hand Held Products, Inc. Optical reader system comprising local host processor and optical reader
US6169789B1 (en) * 1996-12-16 2001-01-02 Sanjay K. Rao Intelligent keyboard system
US6847653B1 (en) * 1999-11-09 2005-01-25 Interwave Communications International, Ltd. Protocol for voice and data priority virtual channels in a wireless local area networking system
JP2001358880A (en) * 2000-06-13 2001-12-26 Fuji Xerox Co Ltd Controller and system for image input/output
US6754197B1 (en) * 2000-09-15 2004-06-22 Atheros, Inc. Method and system for transmit data blocking in a wireless communications network
JP4881503B2 (en) * 2000-09-19 2012-02-22 ソニー株式会社 Command processing method and wireless communication device
ATE517607T1 (en) * 2000-11-30 2011-08-15 Vectura Ltd METHOD FOR PRODUCING PARTICLES FOR USE IN A PHARMACEUTICAL COMPOSITION
AU2002220857A1 (en) * 2000-11-30 2002-06-11 Vectura Limited Particles for use in a pharmaceutical composition
US20020147834A1 (en) * 2000-12-19 2002-10-10 Shih-Ping Liou Streaming videos over connections with narrow bandwidth
KR100467643B1 (en) * 2000-12-28 2005-01-24 엘지전자 주식회사 Method for multimedia data transmission in wireless LAN
US20020089994A1 (en) * 2001-01-11 2002-07-11 Leach, David J. System and method of repetitive transmission of frames for frame-based communications
US7111787B2 (en) * 2001-05-15 2006-09-26 Hand Held Products, Inc. Multimode image capturing and decoding optical reader
US7164678B2 (en) * 2001-06-25 2007-01-16 Intel Corporation Control of processing order for received network packets
US20030059002A1 (en) * 2001-09-24 2003-03-27 Teleware, Inc. Multi-media communication management system for routing incoming calls to a subscriber device that is served by a subscriber station
US7054423B2 (en) * 2001-09-24 2006-05-30 Nebiker Robert M Multi-media communication downloading
US20040068648A1 (en) * 2001-09-24 2004-04-08 Teleware, Inc. Multimedia communication management
US7054416B2 (en) * 2001-09-24 2006-05-30 Meyerson Robert F Modular multi-media communication management system
US20030058805A1 (en) * 2001-09-24 2003-03-27 Teleware Inc. Multi-media communication management system with enhanced video conference services
US7088685B2 (en) * 2001-09-24 2006-08-08 Meyerson Robert F Modular multi-media communication management system with an integrated service for wide area network wireless telephones
US20030058806A1 (en) * 2001-09-24 2003-03-27 Teleware, Inc. Multi-media communication system with advanced conference call management
US20030061622A1 (en) * 2001-09-24 2003-03-27 Nebiker Robert M. Multi-media communication management system with automated paging
US20030059014A1 (en) * 2001-09-24 2003-03-27 Teleware, Inc. Multi-media communication management system with caller managed hold system
US7177412B2 (en) * 2001-09-24 2007-02-13 Berlyoung Danny L Multi-media communication management system with multicast messaging capabilities
US20040015574A1 (en) * 2001-09-24 2004-01-22 Teleware, Inc. Multimedia communication management system with external system management
US20030059021A1 (en) * 2001-09-24 2003-03-27 Teleware, Inc. Multi-media communication management system with selectable call routing
US20030059005A1 (en) * 2001-09-24 2003-03-27 Teleware, Inc. Multi-media communication management system with dynamic bypass routing of real time streaming media
US20030059020A1 (en) * 2001-09-24 2003-03-27 Teleware, Inc. Multi-media communication management system supporting selectable appliance modules
US7177403B2 (en) 2001-09-24 2007-02-13 Meyerson Robert F Event driven multi-media communication management system
US20030137959A1 (en) * 2001-09-24 2003-07-24 Nebiker Robert M. Flexible-link multi-media communication
US7039061B2 (en) * 2001-09-25 2006-05-02 Intel Corporation Methods and apparatus for retaining packet order in systems utilizing multiple transmit queues
US7248593B2 (en) 2001-09-25 2007-07-24 Intel Corporation Method and apparatus for minimizing spinlocks and retaining packet order in systems utilizing multiple transmit queues
US7248604B2 (en) * 2001-10-30 2007-07-24 Ipr Licensing, Inc. Throughput in multi-rate wireless networks using variable-length packets and other techniques
US7876704B1 (en) 2002-01-11 2011-01-25 Broadcom Corporation Tunneling protocols for wireless communications
US6788658B1 (en) 2002-01-11 2004-09-07 Airflow Networks Wireless communication system architecture having split MAC layer
US8027637B1 (en) 2002-01-11 2011-09-27 Broadcom Corporation Single frequency wireless communication system
US7515557B1 (en) * 2002-01-11 2009-04-07 Broadcom Corporation Reconfiguration of a communication system
US7149196B1 (en) * 2002-01-11 2006-12-12 Broadcom Corporation Location tracking in a wireless communication system using power levels of packets received by repeaters
US6862448B1 (en) * 2002-01-11 2005-03-01 Broadcom Corporation Token-based receiver diversity
US7672274B2 (en) 2002-01-11 2010-03-02 Broadcom Corporation Mobility support via routing
US7689210B1 (en) * 2002-01-11 2010-03-30 Broadcom Corporation Plug-n-playable wireless communication system
US7274707B2 (en) * 2002-03-07 2007-09-25 Koninklijke Philips Electronics N. V. Coexistence of stations capable of different modulation schemes in a wireless local area network
US7283468B1 (en) * 2002-03-15 2007-10-16 Packeteer, Inc. Method and system for controlling network traffic within the same connection with different packet tags by varying the policies applied to a connection
US6959865B2 (en) 2002-03-28 2005-11-01 Hand Held Products, Inc. Customizable optical reader
US7532895B2 (en) 2002-05-20 2009-05-12 Air Defense, Inc. Systems and methods for adaptive location tracking
US7058796B2 (en) 2002-05-20 2006-06-06 Airdefense, Inc. Method and system for actively defending a wireless LAN against attacks
US7086089B2 (en) * 2002-05-20 2006-08-01 Airdefense, Inc. Systems and methods for network security
US7383577B2 (en) * 2002-05-20 2008-06-03 Airdefense, Inc. Method and system for encrypted network management and intrusion detection
US20040203764A1 (en) * 2002-06-03 2004-10-14 Scott Hrastar Methods and systems for identifying nodes and mapping their locations
US7277404B2 (en) * 2002-05-20 2007-10-02 Airdefense, Inc. System and method for sensing wireless LAN activity
US7042852B2 (en) * 2002-05-20 2006-05-09 Airdefense, Inc. System and method for wireless LAN dynamic channel change with honeypot trap
US7322044B2 (en) * 2002-06-03 2008-01-22 Airdefense, Inc. Systems and methods for automated network policy exception detection and correction
JP4016728B2 (en) * 2002-06-05 2007-12-05 日本電気株式会社 Voice packet priority control apparatus and method
US7286513B2 (en) * 2002-06-05 2007-10-23 Sigma Designs, Inc. Wireless switch for use in wireless communications
US7113498B2 (en) * 2002-06-05 2006-09-26 Broadcom Corporation Virtual switch
KR100446503B1 (en) * 2002-06-19 2004-09-04 삼성전자주식회사 Compound access point and method for managing voice/data packet using the access point
US20060128376A1 (en) * 2002-07-09 2006-06-15 Alexis Glenroy J Communication systems and methods
US7565115B2 (en) * 2002-07-09 2009-07-21 Xcelis Communications, Llc Communication system for landline and wireless calls
WO2004006512A1 (en) * 2002-07-09 2004-01-15 Xcelis Communications Communication systems and methods
US7586950B1 (en) * 2002-09-13 2009-09-08 Ceterus Networks, Inc. Remote management interface
US20040053624A1 (en) * 2002-09-17 2004-03-18 Frank Ed H. Method and system for optimal load balancing in a hybrid wired/wireless network
KR20040028055A (en) * 2002-09-28 2004-04-03 주식회사 케이티 Apparatus and method for transmitting real-time/non-real-time packet in wireless LAN
US20050180356A1 (en) * 2002-10-01 2005-08-18 Graviton, Inc. Multi-channel wireless broadcast protocol for a self-organizing network
US7421273B2 (en) * 2002-11-13 2008-09-02 Agere Systems Inc. Managing priority queues and escalation in wireless communication systems
US7133386B2 (en) * 2002-11-18 2006-11-07 Cisco Technology, Inc. Method and system for service portability across disjoint wireless networks
US20040203752A1 (en) * 2002-11-18 2004-10-14 Toshiba America Information Systems, Inc. Mobility communications system
US7079521B2 (en) * 2002-11-18 2006-07-18 Cisco Technology, Inc. Method and system for voice calls in a wireless local area network (WLAN)
JP2004173176A (en) 2002-11-22 2004-06-17 Nec Corp Method for restricting communication access between wireless lan terminals
US7529265B1 (en) 2002-12-03 2009-05-05 Rockwell Collins, Inc. Frequency self-organizing radio network system and method
KR100518446B1 (en) * 2002-12-11 2005-09-29 엘지전자 주식회사 Method of Controlling Call Admission in the Mobile Communication System
US20060153117A1 (en) * 2003-01-09 2006-07-13 Guillaume Bichot Method and apparatus for bandwidth provisioning in a wlan
US7801092B2 (en) * 2003-03-21 2010-09-21 Cisco Technology, Inc. Method for a simple 802.11e HCF implementation
US7355996B2 (en) * 2004-02-06 2008-04-08 Airdefense, Inc. Systems and methods for adaptive monitoring with bandwidth constraints
US7324804B2 (en) * 2003-04-21 2008-01-29 Airdefense, Inc. Systems and methods for dynamic sensor discovery and selection
US7522908B2 (en) * 2003-04-21 2009-04-21 Airdefense, Inc. Systems and methods for wireless network site survey
US20040210654A1 (en) * 2003-04-21 2004-10-21 Hrastar Scott E. Systems and methods for determining wireless network topology
US7359676B2 (en) * 2003-04-21 2008-04-15 Airdefense, Inc. Systems and methods for adaptively scanning for wireless communications
US7522518B1 (en) 2003-06-19 2009-04-21 Sprint Communications Company Lp Wireless LAN communication system with in-zone user preferences
US8630168B2 (en) * 2003-06-23 2014-01-14 Intel Corporation Adaptive use of a transmit opportunity
JP4108006B2 (en) * 2003-06-23 2008-06-25 東京電力株式会社 Wireless LAN communication system
JP2005020656A (en) * 2003-06-30 2005-01-20 Nec Corp Radio communication system, its preferential connection method, management system, base station, and terminal station
US7245946B2 (en) * 2003-07-07 2007-07-17 Texas Instruments Incorporated Optimal power saving scheduler for 802.11e APSD
US7315528B2 (en) * 2003-08-11 2008-01-01 Agere Systems Inc. Management of frame bursting
US20050059405A1 (en) * 2003-09-17 2005-03-17 Trapeze Networks, Inc. Simulation driven wireless LAN planning
US20050059406A1 (en) * 2003-09-17 2005-03-17 Trapeze Networks, Inc. Wireless LAN measurement feedback
US20050097248A1 (en) * 2003-10-29 2005-05-05 Kelley Brian H. System and method for establishing a communication between a peripheral device and a wireless device
US6954450B2 (en) * 2003-11-26 2005-10-11 Cisco Technology, Inc. Method and apparatus to provide data streaming over a network connection in a wireless MAC processor
JP4344750B2 (en) * 2003-11-26 2009-10-14 シスコ テクノロジー,インコーポレイテッド Method and apparatus for in-line encryption and decryption of radio station
US8514709B2 (en) * 2003-12-19 2013-08-20 International Business Machines Corporation Autonomic disassociation of clients in a wireless local area network
US7221927B2 (en) * 2004-02-13 2007-05-22 Trapeze Networks, Inc. Station mobility between access points
US20070286132A1 (en) * 2004-03-12 2007-12-13 Vikberg Jari Unlicensed-Licensed Interworking Enhancement Through the Implementation of an Specific Link Control Protocol Layer with Packet Prioritization
US7433670B2 (en) * 2004-03-29 2008-10-07 Avaya Inc. Delivery of buffered frames to power saving stations in wireless local area networks
US8929228B2 (en) * 2004-07-01 2015-01-06 Honeywell International Inc. Latency controlled redundant routing
US8196199B2 (en) 2004-10-19 2012-06-05 Airdefense, Inc. Personal wireless monitoring agent
JP4480563B2 (en) * 2004-12-08 2010-06-16 Okiセミコンダクタ株式会社 QoS control method for wireless LAN base station apparatus
KR100728271B1 (en) * 2004-12-16 2007-06-13 삼성전자주식회사 apparatus and method for Traffic controlling between Wireless LAN device and Access Point in wireless lan system
US8885539B2 (en) * 2005-01-26 2014-11-11 Hewlett-Packard Development Company, L.P. Configurable quality-of-service support per virtual access point (VAP) in a wireless LAN (WLAN) access device
JP4506506B2 (en) * 2005-02-28 2010-07-21 沖電気工業株式会社 Wireless access device and communication control method
US7529925B2 (en) * 2005-03-15 2009-05-05 Trapeze Networks, Inc. System and method for distributing keys in a wireless network
US8201205B2 (en) 2005-03-16 2012-06-12 Tvworks, Llc Upstream bandwidth management methods and apparatus
US7551574B1 (en) * 2005-03-31 2009-06-23 Trapeze Networks, Inc. Method and apparatus for controlling wireless network access privileges based on wireless client location
US20060227729A1 (en) * 2005-04-12 2006-10-12 Honeywell International Inc. Wireless communication system with collision avoidance protocol
US7443809B2 (en) * 2005-04-27 2008-10-28 Symbol Technologies, Inc. Method, system and apparatus for creating a mesh network of wireless switches to support layer 3 roaming in wireless local area networks (WLANs)
US7515573B2 (en) * 2005-04-27 2009-04-07 Symbol Technologies, Inc. Method, system and apparatus for creating an active client list to support layer 3 roaming in wireless local area networks (WLANS)
US20060245393A1 (en) * 2005-04-27 2006-11-02 Symbol Technologies, Inc. Method, system and apparatus for layer 3 roaming in wireless local area networks (WLANs)
US7529203B2 (en) * 2005-05-26 2009-05-05 Symbol Technologies, Inc. Method, system and apparatus for load balancing of wireless switches to support layer 3 roaming in wireless local area networks (WLANs)
US20060268834A1 (en) * 2005-05-26 2006-11-30 Symbol Technologies, Inc. Method, system and wireless router apparatus supporting multiple subnets for layer 3 roaming in wireless local area networks (WLANs)
US20070002833A1 (en) * 2005-06-30 2007-01-04 Symbol Technologies, Inc. Method, system and apparatus for assigning and managing IP addresses for wireless clients in wireless local area networks (WLANs)
JP4563882B2 (en) * 2005-07-06 2010-10-13 Okiセミコンダクタ株式会社 Wireless LAN system and communication method thereof
KR100730610B1 (en) * 2005-09-27 2007-06-21 삼성전자주식회사 Network communication system and control method thereof
US7551619B2 (en) * 2005-10-13 2009-06-23 Trapeze Networks, Inc. Identity-based networking
WO2007044986A2 (en) 2005-10-13 2007-04-19 Trapeze Networks, Inc. System and method for remote monitoring in a wireless network
US7573859B2 (en) 2005-10-13 2009-08-11 Trapeze Networks, Inc. System and method for remote monitoring in a wireless network
US7724703B2 (en) 2005-10-13 2010-05-25 Belden, Inc. System and method for wireless network monitoring
US8638762B2 (en) 2005-10-13 2014-01-28 Trapeze Networks, Inc. System and method for network integrity
US8250587B2 (en) * 2005-10-27 2012-08-21 Trapeze Networks, Inc. Non-persistent and persistent information setting method and system for inter-process communication
US7577424B2 (en) 2005-12-19 2009-08-18 Airdefense, Inc. Systems and methods for wireless vulnerability analysis
US7715800B2 (en) 2006-01-13 2010-05-11 Airdefense, Inc. Systems and methods for wireless intrusion detection using spectral analysis
US20070218874A1 (en) * 2006-03-17 2007-09-20 Airdefense, Inc. Systems and Methods For Wireless Network Forensics
US7971251B2 (en) * 2006-03-17 2011-06-28 Airdefense, Inc. Systems and methods for wireless security using distributed collaboration of wireless clients
US7716389B1 (en) * 2006-03-17 2010-05-11 Bitmicro Networks, Inc. Direct memory access controller with encryption and decryption for non-blocking high bandwidth I/O transactions
US8165301B1 (en) 2006-04-04 2012-04-24 Bitmicro Networks, Inc. Input-output device and storage controller handshake protocol using key exchange for data security
US7558266B2 (en) * 2006-05-03 2009-07-07 Trapeze Networks, Inc. System and method for restricting network access using forwarding databases
US20070260720A1 (en) * 2006-05-03 2007-11-08 Morain Gary E Mobility domain
US20090021343A1 (en) * 2006-05-10 2009-01-22 Airdefense, Inc. RFID Intrusion Protection System and Methods
US20070268514A1 (en) * 2006-05-19 2007-11-22 Paul Zeldin Method and business model for automated configuration and deployment of a wireless network in a facility without network administrator intervention
US8966018B2 (en) 2006-05-19 2015-02-24 Trapeze Networks, Inc. Automated network device configuration and network deployment
US20070268506A1 (en) * 2006-05-19 2007-11-22 Paul Zeldin Autonomous auto-configuring wireless network device
US20070268516A1 (en) * 2006-05-19 2007-11-22 Jamsheed Bugwadia Automated policy-based network device configuration and network deployment
US7577453B2 (en) * 2006-06-01 2009-08-18 Trapeze Networks, Inc. Wireless load balancing across bands
US9191799B2 (en) 2006-06-09 2015-11-17 Juniper Networks, Inc. Sharing data between wireless switches system and method
US7912982B2 (en) 2006-06-09 2011-03-22 Trapeze Networks, Inc. Wireless routing selection system and method
US9258702B2 (en) 2006-06-09 2016-02-09 Trapeze Networks, Inc. AP-local dynamic switching
US8818322B2 (en) 2006-06-09 2014-08-26 Trapeze Networks, Inc. Untethered access point mesh system and method
US7844298B2 (en) 2006-06-12 2010-11-30 Belden Inc. Tuned directional antennas
US7970013B2 (en) 2006-06-16 2011-06-28 Airdefense, Inc. Systems and methods for wireless network content filtering
US20080002734A1 (en) * 2006-06-29 2008-01-03 Haihong Zheng Contention window management for relay networks
US7804806B2 (en) * 2006-06-30 2010-09-28 Symbol Technologies, Inc. Techniques for peer wireless switch discovery within a mobility domain
US20080002607A1 (en) * 2006-06-30 2008-01-03 Ramakrishnan Nagarajan Technique for handling layer 2 roaming in a network of wireless switches supporting layer 3 mobility within a mobility domain
US7961690B2 (en) * 2006-07-07 2011-06-14 Symbol Technologies, Inc. Wireless switch network architecture implementing mobility areas within a mobility domain
US20080008128A1 (en) * 2006-07-07 2008-01-10 Symbol Technologies, Inc. Techniques for resolving wireless client device layer 3 mobility state conflicts between wireless switches within a mobility domain
US7826869B2 (en) * 2006-07-07 2010-11-02 Symbol Technologies, Inc. Mobility relay techniques for reducing layer 3 mobility control traffic and peering sessions to provide scalability in large wireless switch networks
US7916682B2 (en) * 2006-07-14 2011-03-29 Symbol Technologies, Inc. Wireless switch network architecture implementing layer 3 mobility domains
US7724704B2 (en) 2006-07-17 2010-05-25 Beiden Inc. Wireless VLAN system and method
US7639648B2 (en) * 2006-07-20 2009-12-29 Symbol Technologies, Inc. Techniques for home wireless switch redundancy and stateful switchover in a network of wireless switches supporting layer 3 mobility within a mobility domain
US7613150B2 (en) * 2006-07-20 2009-11-03 Symbol Technologies, Inc. Hitless restart mechanism for non-stop data-forwarding in the event of L3-mobility control-plane failure in a wireless switch
US20080020758A1 (en) * 2006-07-20 2008-01-24 Symbol Technologies, Inc. Query-response techniques for reduction of wireless client database size to provide scalability in large wireless switch networks supporting layer 3 mobility
US8281392B2 (en) * 2006-08-11 2012-10-02 Airdefense, Inc. Methods and systems for wired equivalent privacy and Wi-Fi protected access protection
US8340110B2 (en) 2006-09-15 2012-12-25 Trapeze Networks, Inc. Quality of service provisioning for wireless networks
US8072952B2 (en) * 2006-10-16 2011-12-06 Juniper Networks, Inc. Load balancing
US20080107077A1 (en) * 2006-11-03 2008-05-08 James Murphy Subnet mobility supporting wireless handoff
US7873061B2 (en) 2006-12-28 2011-01-18 Trapeze Networks, Inc. System and method for aggregation and queuing in a wireless network
US7865713B2 (en) 2006-12-28 2011-01-04 Trapeze Networks, Inc. Application-aware wireless network system and method
US7885233B2 (en) * 2007-07-31 2011-02-08 Symbol Technologies, Inc. Forwarding broadcast/multicast data when wireless clients layer 3 roam across IP subnets in a WLAN
US20110004913A1 (en) * 2007-07-31 2011-01-06 Symbol Technologies, Inc. Architecture for seamless enforcement of security policies when roaming across ip subnets in ieee 802.11 wireless networks
US8902904B2 (en) 2007-09-07 2014-12-02 Trapeze Networks, Inc. Network assignment based on priority
US8509128B2 (en) 2007-09-18 2013-08-13 Trapeze Networks, Inc. High level instruction convergence function
US8959307B1 (en) 2007-11-16 2015-02-17 Bitmicro Networks, Inc. Reduced latency memory read transactions in storage devices
US8238942B2 (en) 2007-11-21 2012-08-07 Trapeze Networks, Inc. Wireless station location detection
US8150357B2 (en) 2008-03-28 2012-04-03 Trapeze Networks, Inc. Smoothing filter for irregular update intervals
US8474023B2 (en) 2008-05-30 2013-06-25 Juniper Networks, Inc. Proactive credential caching
US8958441B2 (en) 2008-06-05 2015-02-17 Qualcomm Incorporated System and method of an in-band modem for data communications over digital wireless communication networks
US9083521B2 (en) * 2008-06-05 2015-07-14 Qualcomm Incorporated System and method of an in-band modem for data communications over digital wireless communication networks
US8964788B2 (en) 2008-06-05 2015-02-24 Qualcomm Incorporated System and method of an in-band modem for data communications over digital wireless communication networks
US8978105B2 (en) 2008-07-25 2015-03-10 Trapeze Networks, Inc. Affirming network relationships and resource access via related networks
US8036161B2 (en) * 2008-07-30 2011-10-11 Symbol Technologies, Inc. Wireless switch with virtual wireless switch modules
US8238298B2 (en) 2008-08-29 2012-08-07 Trapeze Networks, Inc. Picking an optimal channel for an access point in a wireless network
KR101354130B1 (en) 2008-12-22 2014-01-24 한국전자통신연구원 Method for transmitting and receiving the frame in wireless LAN
JP5350004B2 (en) * 2009-02-19 2013-11-27 キヤノン株式会社 COMMUNICATION DEVICE, COMMUNICATION DEVICE CONTROL METHOD, AND PROGRAM
US8665601B1 (en) 2009-09-04 2014-03-04 Bitmicro Networks, Inc. Solid state drive with improved enclosure assembly
US9135190B1 (en) 2009-09-04 2015-09-15 Bitmicro Networks, Inc. Multi-profile memory controller for computing devices
US8447908B2 (en) 2009-09-07 2013-05-21 Bitmicro Networks, Inc. Multilevel memory bus system for solid-state mass storage
US8560804B2 (en) * 2009-09-14 2013-10-15 Bitmicro Networks, Inc. Reducing erase cycles in an electronic storage device that uses at least one erase-limited memory device
US9590910B1 (en) 2010-05-26 2017-03-07 Marvell International Ltd. Methods and apparatus for handling multicast packets in an audio video bridging (AVB) network
US8363550B1 (en) * 2010-06-15 2013-01-29 Google Inc. Adaptive data unit transmission and acknowledgment
WO2012026990A1 (en) * 2010-08-26 2012-03-01 Marvell World Trade Ltd. Wireless communications with primary and secondary access categories
US8542836B2 (en) 2010-12-01 2013-09-24 Juniper Networks, Inc. System, apparatus and methods for highly scalable continuous roaming within a wireless network
US8868126B2 (en) * 2011-06-30 2014-10-21 Htc Corporation Mobile apparatus with radio frequency architecture supporting simultaneous data and voice communications
JP5569977B2 (en) * 2011-08-04 2014-08-13 Necインフロンティア株式会社 Wireless LAN system, data transmission / reception method and program
US11323337B2 (en) 2011-09-27 2022-05-03 Comcast Cable Communications, Llc Resource measurement and management
US9372755B1 (en) 2011-10-05 2016-06-21 Bitmicro Networks, Inc. Adaptive power cycle sequences for data recovery
US8767546B2 (en) * 2012-03-06 2014-07-01 Itron, Inc. Traffic load and transmission retry management
US9043669B1 (en) 2012-05-18 2015-05-26 Bitmicro Networks, Inc. Distributed ECC engine for storage media
US9602594B2 (en) * 2012-07-31 2017-03-21 Microsoft Technology Licensing, Llc Processing requests
US9319207B2 (en) 2012-11-26 2016-04-19 At&T Intellectual Property I, L.P. System and method for windowing in full-duplex communications
US9106557B2 (en) 2013-03-13 2015-08-11 Comcast Cable Communications, Llc Scheduled transmission of data
US9423457B2 (en) 2013-03-14 2016-08-23 Bitmicro Networks, Inc. Self-test solution for delay locked loops
US9720603B1 (en) 2013-03-15 2017-08-01 Bitmicro Networks, Inc. IOC to IOC distributed caching architecture
US9971524B1 (en) 2013-03-15 2018-05-15 Bitmicro Networks, Inc. Scatter-gather approach for parallel data transfer in a mass storage system
US9842024B1 (en) 2013-03-15 2017-12-12 Bitmicro Networks, Inc. Flash electronic disk with RAID controller
US9916213B1 (en) 2013-03-15 2018-03-13 Bitmicro Networks, Inc. Bus arbitration with routing and failover mechanism
US9501436B1 (en) 2013-03-15 2016-11-22 Bitmicro Networks, Inc. Multi-level message passing descriptor
US9934045B1 (en) 2013-03-15 2018-04-03 Bitmicro Networks, Inc. Embedded system boot from a storage device
US9875205B1 (en) 2013-03-15 2018-01-23 Bitmicro Networks, Inc. Network of memory systems
US9734067B1 (en) 2013-03-15 2017-08-15 Bitmicro Networks, Inc. Write buffering
US10489318B1 (en) 2013-03-15 2019-11-26 Bitmicro Networks, Inc. Scatter-gather approach for parallel data transfer in a mass storage system
US10120694B2 (en) 2013-03-15 2018-11-06 Bitmicro Networks, Inc. Embedded system boot from a storage device
US9672178B1 (en) 2013-03-15 2017-06-06 Bitmicro Networks, Inc. Bit-mapped DMA transfer with dependency table configured to monitor status so that a processor is not rendered as a bottleneck in a system
US9400617B2 (en) 2013-03-15 2016-07-26 Bitmicro Networks, Inc. Hardware-assisted DMA transfer with dependency table configured to permit-in parallel-data drain from cache without processor intervention when filled or drained
US9798688B1 (en) 2013-03-15 2017-10-24 Bitmicro Networks, Inc. Bus arbitration with routing and failover mechanism
US9430386B2 (en) 2013-03-15 2016-08-30 Bitmicro Networks, Inc. Multi-leveled cache management in a hybrid storage system
US9092974B2 (en) * 2013-05-01 2015-07-28 Microsoft Technology Licensing, Llc Mixing data and control codes on a wireless link
US9532186B2 (en) * 2013-11-10 2016-12-27 National Chung Shan Institute Of Science And Technology Bidirectional voice transmission system and method thereof
US10025736B1 (en) 2014-04-17 2018-07-17 Bitmicro Networks, Inc. Exchange message protocol message transmission between two devices
US9952991B1 (en) 2014-04-17 2018-04-24 Bitmicro Networks, Inc. Systematic method on queuing of descriptors for multiple flash intelligent DMA engine operation
US9811461B1 (en) 2014-04-17 2017-11-07 Bitmicro Networks, Inc. Data storage system
US10042792B1 (en) 2014-04-17 2018-08-07 Bitmicro Networks, Inc. Method for transferring and receiving frames across PCI express bus for SSD device
US10078604B1 (en) 2014-04-17 2018-09-18 Bitmicro Networks, Inc. Interrupt coalescing
US10055150B1 (en) 2014-04-17 2018-08-21 Bitmicro Networks, Inc. Writing volatile scattered memory metadata to flash device
WO2016068316A1 (en) * 2014-10-31 2016-05-06 日本電気株式会社 Wireless base station, packet transmission device, wireless terminal, control method and program
US10552050B1 (en) 2017-04-07 2020-02-04 Bitmicro Llc Multi-dimensional computer storage system
US10574427B2 (en) * 2017-10-20 2020-02-25 Foster-Miller, Inc. Assured data transfer for full-duplex communication

Citations (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4168400A (en) * 1977-03-31 1979-09-18 Compagnie Europeenne De Teletransmission (C.E.T.T.) Digital communication system
US4500987A (en) * 1981-11-24 1985-02-19 Nippon Electric Co., Ltd. Loop transmission system
US4503533A (en) * 1981-08-20 1985-03-05 Stanford University Local area communication network utilizing a round robin access scheme with improved channel utilization
US4516239A (en) * 1982-03-15 1985-05-07 At&T Bell Laboratories System, apparatus and method for controlling a multiple access data communications system including variable length data packets and fixed length collision-free voice packets
US4630264A (en) * 1984-09-21 1986-12-16 Wah Benjamin W Efficient contention-resolution protocol for local multiaccess networks
US5029183A (en) * 1989-06-29 1991-07-02 Symbol Technologies, Inc. Packet data communication network
US5103461A (en) * 1989-06-29 1992-04-07 Symbol Technologies, Inc. Signal quality measure in packet data communication
US5115432A (en) * 1989-12-12 1992-05-19 At&T Bell Laboratories Communication architecture for high speed networking
US5142550A (en) * 1989-06-29 1992-08-25 Symbol Technologies, Inc. Packet data communication system
US5157687A (en) * 1989-06-29 1992-10-20 Symbol Technologies, Inc. Packet data communication network
US5231633A (en) * 1990-07-11 1993-07-27 Codex Corporation Method for prioritizing, selectively discarding, and multiplexing differing traffic type fast packets
US5280498A (en) * 1989-06-29 1994-01-18 Symbol Technologies, Inc. Packet data communication system
US5329531A (en) * 1993-03-06 1994-07-12 Ncr Corporation Method of accessing a communication medium
US5343473A (en) * 1992-08-07 1994-08-30 International Business Machines Corporation Method of determining whether to use preempt/resume or alternate protocol for data transmission
US5418812A (en) * 1992-06-26 1995-05-23 Symbol Technologies, Inc. Radio network initialization method and apparatus
US5517495A (en) * 1994-12-06 1996-05-14 At&T Corp. Fair prioritized scheduling in an input-buffered switch
US5528621A (en) * 1989-06-29 1996-06-18 Symbol Technologies, Inc. Packet data communication system
US5668803A (en) * 1989-06-29 1997-09-16 Symbol Technologies, Inc. Protocol for packet data communication system
US5734867A (en) * 1995-07-28 1998-03-31 Motorola, Inc. Method, device, microprocessor and microprocessor memory for instantaneous preemption of packet data
US5815811A (en) * 1989-06-29 1998-09-29 Symbol Technologies, Inc. Preemptive roaming in a cellular local area wireless network
US5841778A (en) * 1997-11-21 1998-11-24 Siemens Business Communication Systems, Inc. System for adaptive backoff mechanisms in CSMA/CD networks
US5844900A (en) * 1996-09-23 1998-12-01 Proxim, Inc. Method and apparatus for optimizing a medium access control protocol
US5870388A (en) * 1995-07-25 1999-02-09 National University Of Singapore, The Radio conferencing method and apparatus
US5872777A (en) * 1997-09-30 1999-02-16 Motorola, Inc. Method and apparatus for conveying data packets in a packet data communication system
US5875179A (en) * 1996-10-29 1999-02-23 Proxim, Inc. Method and apparatus for synchronized communication over wireless backbone architecture
US5933607A (en) * 1993-06-07 1999-08-03 Telstra Corporation Limited Digital communication system for simultaneous transmission of data from constant and variable rate sources
US5982779A (en) * 1997-05-28 1999-11-09 Lucent Technologies Inc. Priority access for real-time traffic in contention-based networks
US6011784A (en) * 1996-12-18 2000-01-04 Motorola, Inc. Communication system and method using asynchronous and isochronous spectrum for voice and data
US6061559A (en) * 1998-03-26 2000-05-09 Telefonaktiebolaget L M Ericsson (Publ) System and method for reconnecting a disconnected low priority call in a mobile telecommunications network
US6078568A (en) * 1997-02-25 2000-06-20 Telefonaktiebolaget Lm Ericsson Multiple access communication network with dynamic access control
US6088591A (en) * 1996-06-28 2000-07-11 Aironet Wireless Communications, Inc. Cellular system hand-off protocol
US6188698B1 (en) * 1997-12-31 2001-02-13 Cisco Technology, Inc. Multiple-criteria queueing and transmission scheduling system for multimedia networks
US6240083B1 (en) * 1997-02-25 2001-05-29 Telefonaktiebolaget L.M. Ericsson Multiple access communication network with combined contention and reservation mode access
US6256334B1 (en) * 1997-03-18 2001-07-03 Fujitsu Limited Base station apparatus for radiocommunication network, method of controlling communication across radiocommunication network, radiocommunication network system, and radio terminal apparatus
US6285662B1 (en) * 1999-05-14 2001-09-04 Nokia Mobile Phones Limited Apparatus, and associated method for selecting a size of a contention window for a packet of data system
US6330231B1 (en) * 1995-10-16 2001-12-11 Nec Corporation Dynamic server allocation for load balancing wireless remote interface processing
US20020054574A1 (en) * 2000-07-27 2002-05-09 Symbol Technologies, Inc. Voice and data wireless communications network and method
US20020089989A1 (en) * 2000-10-04 2002-07-11 Christensen Morten Jagd Method and system for analysing a data packet or frame
US20020101826A1 (en) * 2001-01-31 2002-08-01 Giacopelli James N. Method and systems for bandwidth management in packet data networks
US6438135B1 (en) * 1999-10-21 2002-08-20 Advanced Micro Devices, Inc. Dynamic weighted round robin queuing
US6594240B1 (en) * 1998-05-22 2003-07-15 Lucent Technologies Inc. Methods and apparatus for random backoff based access priority in a communications system
US6678280B1 (en) * 1998-10-28 2004-01-13 Lg Electronics Inc. Voice packet transmission control method in gateway system and device therefor
US6680922B1 (en) * 1998-07-10 2004-01-20 Malibu Networks, Inc. Method for the recognition and operation of virtual private networks (VPNs) over a wireless point to multi-point (PtMP) transmission system
US6721331B1 (en) * 1999-12-15 2004-04-13 At&T Corp. Method and apparatus for decentralized prioritized scheduling in a CSMA/CA wireless system
US6751459B1 (en) * 1999-04-20 2004-06-15 Nortel Networks Limited Nomadic computing with personal mobility domain name system
US6813260B1 (en) * 2000-03-16 2004-11-02 Ericsson Inc. Systems and methods for prioritized access in a contention based network
US6862622B2 (en) * 1998-07-10 2005-03-01 Van Drebbel Mariner Llc Transmission control protocol/internet protocol (TCP/IP) packet-centric wireless point to multi-point (PTMP) transmission system architecture
US20050058147A1 (en) * 1999-12-16 2005-03-17 Regnier Greg J. Method for providing prioritized data movement between endpoints connected by multiple logical channels
US20070008916A1 (en) * 1995-12-07 2007-01-11 Hans-Christian Haugli Wireless packet data distributed communications system

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4138400A (en) * 1975-12-20 1979-02-06 Hoechst Aktiengesellschaft Omega-alkoxy derivatives of lactams
US4500967A (en) 1981-11-27 1985-02-19 United Technologies Corporation Aircraft short-term roll attitude retention system
US4914650A (en) * 1988-12-06 1990-04-03 American Telephone And Telegraph Company Bandwidth allocation and congestion control scheme for an integrated voice and data network
JP2893091B2 (en) * 1990-06-18 1999-05-17 株式会社リコー Optical information recording method
US5594738A (en) * 1993-10-18 1997-01-14 Motorola, Inc. Time slot allocation method
US5729542A (en) 1995-06-28 1998-03-17 Motorola, Inc. Method and apparatus for communication system access
US6104700A (en) 1997-08-29 2000-08-15 Extreme Networks Policy based quality of service
FI974216A (en) 1997-11-12 1999-05-13 Nokia Telecommunications Oy Frame rejection mechanism for packet switches
US6067301A (en) 1998-05-29 2000-05-23 Cabletron Systems, Inc. Method and apparatus for forwarding packets from a plurality of contending queues to an output
US6608816B1 (en) * 1998-11-18 2003-08-19 Nortel Networks Limited Method and apparatus for providing differentiated services using a multi-level queuing mechanism
DE69938094T2 (en) * 1998-11-30 2009-02-05 Matsushita Electric Industries Co. Ltd., Kadoma Packet retransmission control with priority information
US6229795B1 (en) * 1999-01-13 2001-05-08 Qualcomm Incorporated System for allocating resources in a communication system
AU5920000A (en) 1999-07-09 2001-02-13 Malibu Networks, Inc. Method for transmission control protocol (tcp) rate control with link-layer acknowledgements in a wireless point to multi-point (ptmp) transmission system
WO2001099355A1 (en) * 2000-06-23 2001-12-27 Mitsubishi Denki Kabushiki Kaisha Method and system for packet retransmission

Patent Citations (55)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4168400A (en) * 1977-03-31 1979-09-18 Compagnie Europeenne De Teletransmission (C.E.T.T.) Digital communication system
US4503533A (en) * 1981-08-20 1985-03-05 Stanford University Local area communication network utilizing a round robin access scheme with improved channel utilization
US4500987A (en) * 1981-11-24 1985-02-19 Nippon Electric Co., Ltd. Loop transmission system
US4516239A (en) * 1982-03-15 1985-05-07 At&T Bell Laboratories System, apparatus and method for controlling a multiple access data communications system including variable length data packets and fixed length collision-free voice packets
US4630264A (en) * 1984-09-21 1986-12-16 Wah Benjamin W Efficient contention-resolution protocol for local multiaccess networks
US5103461A (en) * 1989-06-29 1992-04-07 Symbol Technologies, Inc. Signal quality measure in packet data communication
US5479441A (en) * 1989-06-29 1995-12-26 Symbol Technologies Packet data communication system
US5029183A (en) * 1989-06-29 1991-07-02 Symbol Technologies, Inc. Packet data communication network
US5142550A (en) * 1989-06-29 1992-08-25 Symbol Technologies, Inc. Packet data communication system
US5157687A (en) * 1989-06-29 1992-10-20 Symbol Technologies, Inc. Packet data communication network
US5815811A (en) * 1989-06-29 1998-09-29 Symbol Technologies, Inc. Preemptive roaming in a cellular local area wireless network
US5280498A (en) * 1989-06-29 1994-01-18 Symbol Technologies, Inc. Packet data communication system
US5668803A (en) * 1989-06-29 1997-09-16 Symbol Technologies, Inc. Protocol for packet data communication system
US5528621A (en) * 1989-06-29 1996-06-18 Symbol Technologies, Inc. Packet data communication system
US5115432A (en) * 1989-12-12 1992-05-19 At&T Bell Laboratories Communication architecture for high speed networking
US5231633A (en) * 1990-07-11 1993-07-27 Codex Corporation Method for prioritizing, selectively discarding, and multiplexing differing traffic type fast packets
US5812589A (en) * 1992-06-26 1998-09-22 Symbol Technologies, Inc. Radio network initialization method and apparatus
US5418812A (en) * 1992-06-26 1995-05-23 Symbol Technologies, Inc. Radio network initialization method and apparatus
US5343473A (en) * 1992-08-07 1994-08-30 International Business Machines Corporation Method of determining whether to use preempt/resume or alternate protocol for data transmission
US5329531A (en) * 1993-03-06 1994-07-12 Ncr Corporation Method of accessing a communication medium
US5933607A (en) * 1993-06-07 1999-08-03 Telstra Corporation Limited Digital communication system for simultaneous transmission of data from constant and variable rate sources
US5517495A (en) * 1994-12-06 1996-05-14 At&T Corp. Fair prioritized scheduling in an input-buffered switch
US5870388A (en) * 1995-07-25 1999-02-09 National University Of Singapore, The Radio conferencing method and apparatus
US5734867A (en) * 1995-07-28 1998-03-31 Motorola, Inc. Method, device, microprocessor and microprocessor memory for instantaneous preemption of packet data
US6330231B1 (en) * 1995-10-16 2001-12-11 Nec Corporation Dynamic server allocation for load balancing wireless remote interface processing
US20070008916A1 (en) * 1995-12-07 2007-01-11 Hans-Christian Haugli Wireless packet data distributed communications system
US6088591A (en) * 1996-06-28 2000-07-11 Aironet Wireless Communications, Inc. Cellular system hand-off protocol
US5844900A (en) * 1996-09-23 1998-12-01 Proxim, Inc. Method and apparatus for optimizing a medium access control protocol
US5875179A (en) * 1996-10-29 1999-02-23 Proxim, Inc. Method and apparatus for synchronized communication over wireless backbone architecture
US6011784A (en) * 1996-12-18 2000-01-04 Motorola, Inc. Communication system and method using asynchronous and isochronous spectrum for voice and data
US6240083B1 (en) * 1997-02-25 2001-05-29 Telefonaktiebolaget L.M. Ericsson Multiple access communication network with combined contention and reservation mode access
US6078568A (en) * 1997-02-25 2000-06-20 Telefonaktiebolaget Lm Ericsson Multiple access communication network with dynamic access control
US6256334B1 (en) * 1997-03-18 2001-07-03 Fujitsu Limited Base station apparatus for radiocommunication network, method of controlling communication across radiocommunication network, radiocommunication network system, and radio terminal apparatus
US5982779A (en) * 1997-05-28 1999-11-09 Lucent Technologies Inc. Priority access for real-time traffic in contention-based networks
US5872777A (en) * 1997-09-30 1999-02-16 Motorola, Inc. Method and apparatus for conveying data packets in a packet data communication system
US5841778A (en) * 1997-11-21 1998-11-24 Siemens Business Communication Systems, Inc. System for adaptive backoff mechanisms in CSMA/CD networks
US6188698B1 (en) * 1997-12-31 2001-02-13 Cisco Technology, Inc. Multiple-criteria queueing and transmission scheduling system for multimedia networks
US6061559A (en) * 1998-03-26 2000-05-09 Telefonaktiebolaget L M Ericsson (Publ) System and method for reconnecting a disconnected low priority call in a mobile telecommunications network
US6594240B1 (en) * 1998-05-22 2003-07-15 Lucent Technologies Inc. Methods and apparatus for random backoff based access priority in a communications system
US7359971B2 (en) * 1998-07-10 2008-04-15 Van Drebbel Mariner Llc Use of priority-based scheduling for the optimization of latency and jitter sensitive IP flows in a wireless point to multi-point transmission system
US6862622B2 (en) * 1998-07-10 2005-03-01 Van Drebbel Mariner Llc Transmission control protocol/internet protocol (TCP/IP) packet-centric wireless point to multi-point (PTMP) transmission system architecture
US6680922B1 (en) * 1998-07-10 2004-01-20 Malibu Networks, Inc. Method for the recognition and operation of virtual private networks (VPNs) over a wireless point to multi-point (PtMP) transmission system
US6678280B1 (en) * 1998-10-28 2004-01-13 Lg Electronics Inc. Voice packet transmission control method in gateway system and device therefor
US6751459B1 (en) * 1999-04-20 2004-06-15 Nortel Networks Limited Nomadic computing with personal mobility domain name system
US6285662B1 (en) * 1999-05-14 2001-09-04 Nokia Mobile Phones Limited Apparatus, and associated method for selecting a size of a contention window for a packet of data system
US6438135B1 (en) * 1999-10-21 2002-08-20 Advanced Micro Devices, Inc. Dynamic weighted round robin queuing
US6721331B1 (en) * 1999-12-15 2004-04-13 At&T Corp. Method and apparatus for decentralized prioritized scheduling in a CSMA/CA wireless system
US20050058147A1 (en) * 1999-12-16 2005-03-17 Regnier Greg J. Method for providing prioritized data movement between endpoints connected by multiple logical channels
US20090046735A1 (en) * 1999-12-16 2009-02-19 Regnier Greg J Method for providing prioritized data movement between endpoints connected by multiple logical channels
US6813260B1 (en) * 2000-03-16 2004-11-02 Ericsson Inc. Systems and methods for prioritized access in a contention based network
US6404772B1 (en) * 2000-07-27 2002-06-11 Symbol Technologies, Inc. Voice and data wireless communications network and method
US20050281235A1 (en) * 2000-07-27 2005-12-22 Beach Robert E Voice and data wireless communications network and method
US20020054574A1 (en) * 2000-07-27 2002-05-09 Symbol Technologies, Inc. Voice and data wireless communications network and method
US20020089989A1 (en) * 2000-10-04 2002-07-11 Christensen Morten Jagd Method and system for analysing a data packet or frame
US20020101826A1 (en) * 2001-01-31 2002-08-01 Giacopelli James N. Method and systems for bandwidth management in packet data networks

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8149796B2 (en) 2000-07-27 2012-04-03 Symbol Technologies, Inc. Voice and data wireless communications network and method
US20050281252A1 (en) * 2000-07-27 2005-12-22 Beach Robert E Voice and data wireless communications network and method
US8660061B2 (en) 2000-07-27 2014-02-25 Symbol Technologies, Inc. Voice and data wireless communications network and method
US8189542B2 (en) 2000-07-27 2012-05-29 Symbol Technologies, Inc. Voice and data wireless communications network and method
US20050025105A1 (en) * 2003-07-30 2005-02-03 Seon-Soo Rue Apparatus and method for processing packets in wireless local area network access point
US20050165946A1 (en) * 2003-12-22 2005-07-28 Intel Corporation Bi-directional wireless LAN channel access
US20060198301A1 (en) * 2005-03-07 2006-09-07 Texas Instruments Incorporated Packet-level service differentiation for quality of service provisioning over wireless local area networks
US7876758B2 (en) * 2005-04-08 2011-01-25 Agere Systems Inc. Method and apparatus for improved voice over Internet protocol (VoIP) transmission in a digital network
US20060227782A1 (en) * 2005-04-08 2006-10-12 Bullman William R Method and apparatus for improved voice over Internet protocol (VoIP) transmission in a digital network
US20090168793A1 (en) * 2006-03-30 2009-07-02 David Fox Prioritising Data Transmission
US8649389B2 (en) * 2006-03-30 2014-02-11 Vodafone Group Services Limited Prioritising data transmission
US20090190566A1 (en) * 2008-01-30 2009-07-30 Samsung Electronics Co., Ltd. Method and apparatus of controlling access mode for communication system using shared or unlicensed band
US8681765B2 (en) * 2008-01-30 2014-03-25 Samsung Electronics Co., Ltd. Method and apparatus of controlling access mode for communication system using shared or unlicensed band

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