WO2001050151A9

WO2001050151A9 - Integration of bluetooth functionality with a global positioning system

Info

Publication number: WO2001050151A9
Application number: PCT/US2001/000071
Authority: WO
Inventors: Alain Fogel
Original assignee: Brightcom Technologies Ltd; Alain Fogel; Friedman Mark M
Priority date: 2000-01-06
Filing date: 2001-01-02
Publication date: 2002-07-18
Also published as: WO2001050151A1; AU3084801A

Abstract

A method for localizing a moving object using a satellite based potioning system such as a global position system (GPS) (47) and a short range wireless system (74) such as a system that conforms to the Bluetooth specifications. Localization of a moving object is accomplished using GPS when sufficient satellites are visible. GPS correlation computations are performed either on-line with an application specific integrated circuit (ASIC) (42) or off-line with a digital signal processor (DSP). If insufficient satellites are visible, the locations of one or more nearby Bluetooth base stations are used to supplement or replace the GPS computation results to enable more accurate cellular phone localization. A cellular phone with a location detector function which integrates GPS and Bluetooth technology can be used for emergency localization in both outdoor and indoor settings. Bluetooth functionality is integrated in the cellular phone with a GPS system through the addition of a Bluetooth antenna (60), a Bluetooth RF radio (70), and a Bluetooth ASIC (72), all of which optionally are combined with components of prior art cellular phones. Integration of Bluetooth-GPS can also be used to improve navigational systems.

Description

INTEGRATION OF BLUETOOTH FUNCTIONALITY WITH A GLOBAL POSITIONING SYSTEM

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to a method of the integration of Bluetooth

functionality with a Global Positioning System (GPS) to allow localization in satellite shielded areas, and more particularly to a location detector apparatus installed in cellular phones. The method of the present invention is also applicable to navigation

devices..

In the U.S. legislation has been passed (Emergency Service Ruling U.S. FCC 911) mandating that a location detector be installed in every cellular phone in case of emergency. The E91 1 regulations specifies the required precision to be about 100 m. and the maximum time to complete an E911 call to be between 15 and 17 seconds. The position of the cellular phone should therefore be computed (acquisition time) within about four seconds. In Europe, a similar project called MORE has begun. The Emergency localization feature will be introduced on the cellular market starting from 2001.

There are two main competing technologies for localization. The first one is GPS, a satellite based positioning system which uses an array of 24 satellites (U.S.) or likewise the grid of Russian satellites (GLOSNASS). GPS has been adopted by project MORE as its localization technology. Using the civilian code of GPS (C/A), the precision is limited to about 100 m due to a degradation of the performance which is introduced by the U. S. Department of Defense. This degradation can be suppressed using a Differential scheme called DGPS, in which case the precision is better than 20 m.

GPS receivers determine their position by computing the relative time of

arrival of signals transmitted simultaneously from a multiplicity of satellites. The 5 satellites transmit both satellite positioning data as well as data on clock timing. In order to compute the position of the receiver, the receiver uses transmitted satellite timing data, satellite positioning data and pseudoranges which are the time delays

measured between the received signal from each satellite and a local clock. Generally, correlation methods are used to compute pseudoranges. The received signal which 10 contains high rate satellite-specific repetitive code sequences is correlated with a stored replica of the appropriate code sequences.

Therefore the heart of a GPS system is a correlation engine, the purpose of which is compute the pseudoranges from the GPS device to at least four satellites.

Using more time for integration of the correlations, it is possible to improve the _. 15 sensitivity of the GPS devices, but this works only within a limited range (e.g. 20 m) from a window without walls separating the GPS device from a window access and provided that there are enough satellites in view. Hence, GPS fails for in-door

computations, i.e. localization in buildings, e.g. in Manhattan skyscrapers. Schuchman et al (U.S. Patent No. 5,365,450) teach a cellular phone with a GPS receiver but the

20 localization capabilities are limited to instances when there are enough satellites in view. Krasner (U.S. Patent No. 5,663,734), which is included by reference for all purposes as if fully set forth herein, demonstrates a fine example of a method for

processing GPS signals. Using the Fast Fourier Transform (FFT) algorithm, very rapid computation of the pseudoranges is allowed by performing rapidly a large number of correlation operations. The efficient processing of data using fast

convolution methods allows the processing of signal at low received levels (e.g. when reception is poor due to partial blockage), but not when satellites are completely blocked.

The second main technology for localization is wireless triangulation. The

method computes the ranges of a person carrying such a device to at least three base stations. This method requires that the base stations be fitted with the required software. Duffet -Smith (International Patent No. WO 94/28432) demonstrates an apparatus for the determination of the position of a roving receiver within a space shielded from receipt of signals from the transmission sources (such as a tunnel). The apparatus uses equipment for producing substitute signals locked in phase with signals from the transmission sources and a curvilinear transmission element extending within the shielded space for generating fields in the shielded space The main drawback of the triangulation method is that it does not ensure privacy because tracking of a mobile phone incorporating triangulation begins as soon as the mobile

phone is turned on. As mentioned above, in Europe, the GPS method has already been chosen over wireless triangulation. In the U.S., a decision has not yet been reached

There is thus a widely recognized need for, and it would be highly advantageous to have, a positioning system which would rely on GPS technology but would also work when satellites are blocked such as in high-rise buildings and tunnels. SUMMARY OF THE INVENTION

According to the present invention there is provided a method for localizing a moveable object including the steps of: a) providing a short range wireless base station having a location; and b) interrogating the location of the short range wireless base station by the moveable object.

According to preferred embodiments the providing step includes establishing

the location of the short range wireless system base station.

According to further features in preferred embodiments of the invention described below, the method also includes the steps of: c) receiving satellite based

positioning system signals; d) processing the satellite based positioning system signals to extract satellite based positioning system intermediate location data; and e) reconciling the satellite based positioning system intermediate location data with a previously computed location of the moveable object. In a preferred embodiment, the reconciling reconciles the satellite based positioning system intermediate location data with both the location of the short range wireless base station and with a previously computed location of the moveable object to determine an updated location of the

moveable object.. In a second embodiment, reconciling reconciles first the satellite based position system intermediate location data with a previously computed location of the movable object and then the result of the first reconciling with the location of the short range wireless base station to determine an updated location of the moveable object.

Preferably, the processing includes correlating the satellite based positioning system signals, and the satellite based positioning system intermediate location data include results of the correlating. The method further includes either the step of transmitting the updated object location to a third party; or the step of displaying the updated object location.. In a preferred embodiment, transmitting is activated in response to an emergency.

According to one embodiment of the present invention, the processing of the

satellite based positioning system signals to extract satellite based positioning system

intermediate location data is effected in real time by steps including: (i) digitizing the received satellite based positioning system signal; and (ii) performing correlation

computations on the digitized signal.

According to another embodiment of the present invention, the processing of the satellite based positioning system signals to extract satellite based positioning system intermediate location data is effected off line by steps including: (i) digitizing the received satellite based positioning system signal; (ii) storing the digitized signal, and (iii) performing correlation computations on the stored signal.

According to the present invention there is provided a cellular phone with a location detector function, including: a) at least one antenna for receiving satellite based positioning system signals and short range wireless communication system signals; b) a first mechanism for receiving satellite based positioning system signals from the at least one antenna and calculating satellite based positioning system intermediate location data based on the satellite based positioning system signals; and c) a second mechanism for receiving short range wireless communication system signals from the at least one antenna, wherein the received signal contains a substitute

location of the cellular phone.

According to further features of preferred embodiments of the invention described below the apparatus further includes: d) a third mechanism for transmitting location information connected to the satellite based positioning system intermediate location data and the substitute location. Preferably, the at least one antenna is used for transmitting the information via a cellular channel and the third mechanism includes: (i) a microcontroller for controlling the cellular phone; and (ii) a mobile RF radio for transmitting the information via the at least one antenna.

The first mechanism preferably includes: (i) a satellite based positioning system RF radio for receiving signals from the at least one antenna; and (ii) a satellite based positioning system application specific integrated circuit for calculating satellite based positioning system intermediate location data based on the received signals. The first mechanism preferably further includes: (iii) a digital signal processor for reconciling the satellite based positioning system intermediate location data with a previously computed location of the cellular phone.

In another embodiment, the first mechanism includes: (i) a satellite based positioning system RF radio for receiving signals from the at least one antenna; and (ii) a digital signal processor for calculating the satellite based positing system

intermediate location data based on the received signals.

According to further aspects of preferred embodiments of the current invention, the second mechanism includes: (i) a short range wireless system RF radio for receiving signals from the at least one antenna; and (ii) a short range wireless system application specific integrated circuit for receiving a substitute position of the cellular phone from the short range wireless system RF radio.

According to the present invention there is provided a cellular phone with a location detector function including: a) An integrated RF radio including mobile RF functionality, satellite based positioning system RF functionality and short range wireless system RF functionality; and b) at least one antenna for receiving satellite based positioning system signals and short range wireless communication system signals, operationally connected to the integrated RF radio.

Preferably, the apparatus further includes: c) an integrated digital signal processor (DSP) operationally connected to the integrated RF radio; and d) an

integrated microcontroller, acting as a short range wireless communication system digital modem, operationally connected to the integrated DSP.

The present invention successfully addresses the shortcomings of the presently known configurations by providing a method of localization which integrates short range wireless system functionality (as exemplified by the Bluetooth specification)with a satellite based positioning system (as exemplified by the Global Position System (GPS)). More specifically, the integration of GPS and Bluetooth in the form of a location detector in a cellular phone can be used in the case of an emergency to locate an individual with a cellular phone which is shielded from satellite view as long as the cellular phone is near a Bluetooth access point as defined below.

In a preferred embodiment, the location detector feature on the cellular phone is activated by the user of the cellular phone or automatically in the case of an emergency such as a car accident, and allows the localization of the cellular phone within E911 guidelines.

Bluetooth can also be integrated into GPS based navigation devices to facilitate navigation in satellite-shielded environments. BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to

the accompanying drawings, wherein:

Figure 1 shows an outside view of a prior art cellular phone with a GPS based

location detector;

FIG. 2 is a block diagram of a prior art cellular phone with GPS functionality using an application specific integrated circuit (ASIC) based correlation technique;

FIG. 3 is a block diagram of a prior art cellular phone with GPS functionality using a digital signal processing (DSP) based correlation technique; FIG. 4 shows the network topology of a piconet;

FIG 5 shows an outside view of a cellular phone with a GPS and Bluetooth based location detector;

FIG 6 illustrates the programming of a Bluetooth access point;

FIG. 7 is a is a block diagram of a cellular phone with Bluetooth and GPS functionality using GPS application specific integrated circuit (ASIC) based correlation technique;

FIG. 8 is a is a block diagram of a cellular phone with Bluetooth and GPS functionality using a GPS digital signal processing (DSP) based correlation technique;

FIG. 9 is a block diagram of a cellular phone with a higher level of integration

of Bluetooth and GPS functionality.

Figure 10 illustrates a navigation system using GPS and Bluetooth. DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is of a method of integrating Bluetooth functionality with a Global Positioning System (GPS), and of related devices. A device of the present invention include a cellular phone with a location detector. The method can

also be used to improve navigational devices. Specifically, the present invention can be used to localize individuals or objects, shielded from satellite view.

The principles and operation of the integration of Bluetooth functionality with a Global Positioning System according to the present invention may be better understood with reference to the drawings and the accompanying description. Refer to Figure 1 which shows the external appearance of a prior art cellular

phone 10 with a location detector function based on GPS technology. Ah emergency button 12 and a GPS antenna 14 are added to a cellular phone with a standard mobile antenna 32. Although antennas 14 and 32 are separated in Figure 1, it should be evident to those skilled in the art that antennas 14 and 32 can be combined into one antenna. Signals 16, 18, 20, and 22 from satellites 24, 26, 28, and 30, are periodically

received when available by GPS antenna 14 and are used to calculate the user's position, as detailed below. Throughout the following discussion, it is assumed that the location detector function on cellular phone 10 is activated by an automatic trigger in the case of an emergency such as a car accident or by a user pressing push button

12 when the user desires to be located but does not have sufficient time to dial a third party, such as in the case of an illness. However, is should be evident to those skilled in the art, that the location detector function can be activated by other means than those previously mentioned and in non-critical situations. When the location detector function is activated, updated signals 16, 18, 20, and 22 are used to calculate the user's position and the user's position is automatically transmitted by mobile antenna 32 to a third party which is represented here as emergency station 36 (e.g. "91 1") via a signal 34.

Figures 2 and 3 illustrate two embodiments of the inside of cellular phone 10

with a GPS location detector function, their differences being the technique used to

perform correlation calculations.

Figure 2 is a block diagram of a first embodiment 40 of cellular phone 10. An off the shelf GPS receiver chip set 47 which includes a GPS application specific integrated circuit ASIC 42 such as the SiRFstarl ASIC manufactured by the SiRF

company (Santa Clara, California)along with a GPS RF radio 44 is added to a mobile phone chip set 46. Mobile phone chip set 46 consists of a microcontroller 48, mobile digital signal processor DSP 50, and a mobile RF radio 52 with mobile RF radio 52 providing "mobile RF functionality". The operation of mobile phone chip set 46 is well known in the art and microcontroller 48 here acts as the host controller of cellular

phone 10 and also as the communications controller.

Signals 16, 18, 20, and 22 as they are received by GPS antenna 14, are passed via GPS RF radio 44 (providing "satellite based positioning system RF functionality") to GPS ASIC 42. GPS ASIC 42 digitizes (samples and quantizes) each of signals 16, 18, 20 and 22, and performs the necessary correlation calculations in real time to derive GPS intermediate location data. GPS intermediate location data, which represents the intermediate step between the raw data contained in signals 16, 18, 20, and 22 and the finalized computed updated location, and in the preferred embodiment includes the calculated correlation results, is passed to mobile DSP 50 or microcontroller 48. Mobile DSP 50 or microcontroller 48 reconciles the GPS intermediate location data computed by GPS ASIC 42 with a previously calculated position of cellular phone 10 to arrive at a newly computed updated position of cellular phone 10. While signals 16, 18, 20, and 22 continue to be processed to

compute the position of cellular phone 10, the updated position information is passed via mobile RF radio 52 to mobile antenna 32 for transmission. The usage of GPS ASIC 42 in embodiment 40 enables continuous localization and navigation. It can

offer excellent acquisition time (less than 2 sec.) On the other hand, the drawback is that it requires a special ASIC.

Figure 3 is a block diagram of a second embodiment 53 of cellular phone 10

which is a digital signal processing based solution in which each of the received signals 16, 18, 20, and 22 is digitized (i.e. sampled and quantized) and stored. Mobile DSP 50 (reconfigured to include the necessary software) performs correlation on the stored samples (typically 4 Mbit of RAM) to derive GPS intermediate location data, and reconciles the GPS intermediate location data with a previously computed position of cellular phone 10 to arrive at a newly computed updated position of cellular phone 10 as per prior art U.S. patent number 5,663,734 described above. As an alternative, reconciliation of the GPS intermediate location data with the previously computed position of cellular phone 10 can be performed in

microcontroller 48. The localization is computed off-line after the samples are stored in embodiment 53. Therefore, in contrast with the device 40 of Figure 2, the updated position information which is calculated and passed via mobile RF radio 52 to mobile antenna 32 for transmission corresponds to an earlier in time position of cellular

phone 10. This solution therefore cannot provide continuous localization. A significant drawback of embodiment 53 relative to embodiment 40 is that during the emergency call, the person cannot talk simultaneously with the GPS computations. Note that a typical mobile DSP 50 is busy at least 25% to 50% performing the voice DSP algorithms including compression and decompression.

Because a conversation with an emergency station cannot be interrupted, the GPS computation time (normally a few seconds) might be doubled due to the priority of

voice DSP algorithms and embodiment 53 may not satisfy the requirement that an emergency call be completed by between 15-17 seconds. In this example, mobile DSP 50 is used to perform both the voice DSP algorithms and the GPS locator correlation calculations, however it is evident to those skilled in the art that a separate DSP could also be used for GPS calculations. A second DSP would allow simultaneous talking and GPS computations but would increase the cost of the location detector device installed in cellular phone 10.

The embodiments represented in Figures 2 and 3 assume that cellular phone 10 is digital but an analog cellular phone could instead be used, provided that a mobile

DSP 50 is added to the base analog cellular phone.

The integration of GPS into cellular phone 10 as illustrated in figures 1, 2, and

3, would be sufficient in the situation that satellites are not blocked. It will now be discussed how the addition of Bluetooth functionality will allow localization for in- door computations, and for outdoor situations where satellites are blocked such as in tunnels.

Bluetooth technology is an open specification for wireless communication of data and voice in a short range wireless communication system. It is based on a low- cost short-range radio link, built into a 9 x 9 mm microchip, facilitating connections for stationary and mobile communication environments. Bluetooth technology allows for the replacement of the many proprietary cables that connect one device to another with one universal short-range radio link. Due to its advantages, Bluetooth is expected to be installed in buildings and offices for the purpose of Home networking, Small Office Networking, Information attainment services and proximity mobile

communication. Bluetooth can also be installed in tunnels and other places where

satellites are blocked. The fact that the range of Bluetooth is 10 m, but even if extended to 100 m will still meet E911 requirements makes it the simplest solution for in-door or outdoor satellite-blocked localization. In the context of this invention, a

range up to 100 m is defined as a "short range".

Figure 4 illustrates a piconet 56 which is a collection of devices (two devices are shown in Figure 4) connected via Bluetooth technology in an ad hoc function. Before any connections in a piconet are created, devices 61 and 54 are in STANDBY mode. In this mode, an unconnected unit periodically "listens" for messages every 1.28 seconds. Each time a device wakes up, it listens on a set of 32 hop frequencies defined for that unit. The number of hop frequencies varies in different geographic

regions; 32 is the number for most countries (except apan, Spain and France). The connection procedure is initiated by any of the devices which then becomes master. In the present example, device 61 is a cellular phone, and device 54 is configured as a Bluetooth access point i.e. a base station that is configured to send its location, on

request, to cellular phone 61. The connection procedure is assumed to be initiated when the location detector function on cellular phone 61 (see figure 5) is activated causing cellular phone 61 to become a master. Because the address of nearby stationary device 54 is initially unknown by cellular phone 61, a connection is made by an INQUIRY message sent by cellular phone 61 followed by a subsequent PAGE message.

Refer to Figure 5 which shows the exterior of a cellular phone 61 of the

present invention, with a location detector function based on GPS and Bluetooth

technology. Externally, cellular phone 61 is identical to cellular phone 10 of Figure 1

except for the addition of a Bluetooth antenna 60. Although antennas 14, 32, and 60 are shown separated in Figure 3, it should be evident to those skilled in the art that

antennas 14, 32, and 60 can be combined into one or two antennas. When emergency push-button 12 is pushed or the location detector function is automatically activated,

in addition to the GPS processing described above, cellular phone 61 initiates the transmission, via Bluetooth antenna 60, of an INQUIRY message via a signal 62, which is answered by device 54. Cellular phone 61 then forms piconet 56 with device 54. According to the Bluetooth standard, piconet 56 could contain up to 8 units. Device 54 transmits its location (latitude, longitude and altitude) via a return signal 64

to Bluetooth antenna 60. Device 54' s location (which functions as a "substitute

location" for cellular phone 61) can be used by cellular phone 61 to determine the position of cellular phone 61 either in addition to the results of the GPS calculations or in replacement of them (as explained in more detail below).

The location (latitude, longitude, and altitude) of nearby stationary device 54 is previously programmed using a special purpose computer 66 such as a laptop or personal digital assistant as shown in Figure 6. Upon installation of device 54, special purpose computer 66 computes the location of device 54 using GPS data in the case of outdoor computations. For in-door computations, computer 66 is equipped with a software program which allows computer 66 to compute device 54's position from the GPS position of the building and a computerized map of the building (including floors

and room numbers) in which device 54 is being installed. The computed location is transmitted by a Bluetooth wireless modem 68 to device 54. Once device 54 has had its location programmed, it is called a "Bluetooth access point" or a "Bluetooth base

station" and can be used for cellular phone localization purposes as explained above. Alternatively device 54 is allocated a unique identification number and device 54's location (street address, floor number, room number etc.) is recorded in a lookup table (not shown). When queried, device 54 transmits its identification number

(instead of or in addition to device 54's location) to cellular phone 61 via return signal

64. A lookup table is used to determine the location of device 54 (and hence cellular phone 61) corresponding to the received identification number. This alternative eliminates the need for the pre-programming, as illustrated in Figure 6, of location (latitude, longitude, and altitude) of device 54.

In the discussion above it is assumed that for privacy purposes cellular phone 61 does not initiate the Bluetooth connection procedure unless the location detector function is activated by the user or an automatic trigger, however it should be evident to those skilled in the art that initiation of the connection procedure could also be the default mode of cellular phone 61. In the latter case, whenever cellular phone 61 is near a base station such as device 54, device 54 transmits the location of device 54 (or

alternate data such as an identification number) via signal 64 to Bluetooth antenna 60. Cellular phone 61 uses the Bluetooth location data together with the GPS intermediate location data in order to periodically update the estimate of the location of mobile 61 (as described below). Transmission of the updated position information to station 36

via signal 34 still only occurs upon activation of the location detector. Figure 7 is a block diagram of one embodiment 75 of cellular phone 61 with Bluetooth functionality. A Bluetooth chip set 74 is added to GPS chip set 47 and mobile phone chip set 46. The functionality of GPS chip set 47 and mobile phone chip set 46 are as described in Figure 2. Bluetooth chip set 74 contains a Bluetooth RF

radio 70, providing "short range wireless system RF functionality" and a Bluetooth

ASIC 72, which is essentially a digital modem that provides "Bluetooth ASIC functionality". Alternatively, Bluetooth ASIC functionality can be provided partially by Bluetooth ASIC 72 and partially by a reconfigured microcontroller 48 through a

partition of the Bluetooth protocol stack with the lower levels of the protocol implemented on Bluetooth ASIC 72 and the higher levels on microcontroller 48. Bluetooth ASIC 72 can be developed using the Bluetooth specification or by using a development kit such as the one offered by Symbionics Ltd., Cambridge, England (a subsidiary of Cadence Design Systems, Inc., San Jose, California, USA).

The location of Bluetooth access point 54 which is received by Bluetooth antenna 60 from device 54 is passed via Bluetooth RF radio 70 to Bluetooth ASIC 72 and on to mobile DSP 50 or to microcontroller 48 where it is reconciled with GPS intermediate location data as discussed below.

Figure 8 is a block diagram of a second embodiment 77 of cellular phone 61 with Bluetooth functionality. Bluetooth receiver chip set 74 is added to GPS RF radio 44 and mobile phone chip set 46. The operation of GPS RF radio 44 and mobile

phone chip set 46 are as described in Figure 3. The operation of Bluetooth chip set 74 is as described in Figure 7.

In both embodiments 75 and 77 as shown in Figures 7 and 8, mobile DSP 50 uses the GPS intermediate location data as long as this data are sufficient to obtain a reliable position. The GPS intermediate location data is reconciled with the previously computed position of cellular phone 61 through an algorithm such as a Kalman filter that is run by mobile DSP 50. In one embodiment of the current invention, microcontroller 48 monitors the position error covariance, which is a by- product of the Kalman filter algorithm to determine whether GPS intermediate location data are sufficient. If cellular phone 61 is close to a Bluetooth access point

(in our example device 54) which is programmed to send its location to mobile

Bluetooth receiver 74, and the Bluetooth connection procedure has been initiated, the Bluetooth received location can also be reconciled with the GPS intermediate location data and the previously computed cellular phone position to arrive at the updated position of cellular phone 61. Bluetooth reconciliation can occur in one of two ways:

• If the results of the reconciliation of GPS intermediate location data with the previously computed position of cellular phone 61 turn out to be totally unreliable as in the case of the position error covariance from the Kalman filter reaching a preset validity threshold, then the position of Bluetooth access point 54 are used instead by DSP 50 as a replacement for an updated position of cellular phone 61.

This is normally the case for in-door locations.

• The position of Bluetooth access point 54 is passed to mobile DSP 50 and is used

as a complement to missing GPS data, e.g. in case less than four satellites are in view. . Dead-Reckoning is the GPS terminology for providing location data which are in addition to the satellite data. According to the prior art, Dead-Reckoning

data are provided by a compass or a gyro and are added to the Kalman filter state variables when performing the reconciliation. The term "Dead-Reckoning" is understood in the context of the present invention to refer to reconciliation of GPS intermediate location data with the previously computed position of cellular

phone 61 by the Kalman filter. Here, the received position of Bluetooth access point 54 provides the Dead Reckoning data, establishing a new method of Dead Reckoning.

In another embodiment of the current invention, reconciliation is performed in

two steps. Mobile DSP 50 first reconciles GPS intermediate location data with the previously computed cellular phone position to arrive at a GPS finalized location. Mobile DSP 50 then reconciles the GPS finalized location with the position of Bluetooth access point 54 to arrive at the updated position of cellular phone 61.

As an alternative to reconciliation procedures performed by mobile DSP 50, that are described above, reconciliation can be instead performed by microcontroller 48 (reconfigured to include the necessary software) using a "simple" Kalman filter or data fusion algorithm, assuming that microcontroller 48 is not powerful enough to run a full Kalman filter. A full Kalman filter is a multidimensional adaptive filter, the coefficients of which are adapted each time there are new input data. In a "simple"

Kalman filter, the computational burden is reduced by, for example, adapting the coefficients every N-th time that new data are input, or by using a filter of reduced dimensionality. See, for example, R. G. Brown and P. Y. C. Hwang, Introduction to Random Signals and Applied Kalman Filtering, Third Edition, John Wiley & Sons, 1997 The "simple" Kalman filter is less CPU-consuming but performs sub-optimally to a full Kalman filter algorithm.

It will be evident to those experts in the art that higher levels of integration of GPS and Bluetooth locator technology in cellular phones are also possible with this invention. Figure 9 shows a possible configuration 83 where all RF radios 44, 52, and 70 are integrated into one RF radio 78 and Bluetooth ASIC 72 along with GPS ASIC 42 are integrated with microcontroller 48 to form advanced microcontroller block 82. In addition, although mobile antenna 32, GPS antenna 14, and Bluetooth antenna 60 are shown as separate units in Figure 9, it should be evident to those skilled in the art

that mobile antenna 32, GPS antenna 14, and Bluetooth antenna 60 can be combined

into fewer than three antennas. An advanced mobile DSP 80 can, if desired, perform GPS correlation and reconciliation of position data, along with its usual voice DSP algorithms. In addition to acting as a host controller and communication controller, advanced microcontroller 82 acts as a Bluetooth digital modem, and can, if desired,

monitor position error covariance, and perform position reconciliation.

In embodiments 75, 77, and 83 illustrated in Figures 7, 8, and 9, transmission of the updated position information via mobile antenna 32 is powered off when microcontroller 48 or 82 determines that third party 36 has received signal 34. In addition, microcontroller 48 or 82 disables GPS computations when not needed to save power.

In a different embodiment of the present invention, reconciliation is performed by a GPS base station server (not shown), rather than by cellular phone 61 or by the cellular phone represented by embodiment 83. GPS intermediate location data along with the position of Bluetooth access point 54, if necessary, are sent by micro-

controller 48 or 82 using mobile antenna 32 to a GPS base station server (not shown). At the GPS base station server, these data are reconciled with the previously computed cellular phone position using an algorithm such as the Kalman filter. The GPS base station server then sends the updated position directly to third party 36. Although the integration of Bluetooth GPS has been described above in the context of a location detector for a cellular phone, integration of Bluetooth-GPS can also be used for other purposes such as improving a navigation GPS in a moving

vehicle as shown in embodiment 87 of Figure 10. In this context Bluetooth is used as an additional localization device in places where satellites are blocked such as in a tunnel 100. Bluetooth base stations 96 (only one shown here) with a range of 100m

are located every 100 m in a tunnel 100. Because moving vehicle 92 is in tunnel 100,

GPS antenna 98 does not receive GPS signals, however in other embodiments GPS signals are received by antenna 98. Whenever moving vehicle 92 approaches a

Bluetooth base station 96, Bluetooth base station 96 sends its location via signal 104. The location of Bluetooth base station 96 and GPS intermediate location data are reconciled as described above and the location of moving vehicle 92 is in one embodiment of the current invention displayed on navigation display 90.

In the context of localization as described above, mobile antenna 32, can be

used to GPS intermediate location data, the position of Bluetooth access point 54, in addition to or in place of the updated position of the cellular phone. All such information is referred to in this invention as "location information connected to the satellite based positioning system intermediate location data and the substitute

location". While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other

applications of the invention may be made.

Claims

WHAT IS CLAIMED IS

1. A method for localizing a movable object comprising the steps of: a) providing a short range wireless base station having a location; and b) interrogating said location of said short range wireless base station by the moveable object.

2. The method of claim 1, wherein said providing includes establishing said location of said short range wireless system base station.

3. The method of claim 1, further comprising the steps of: c) receiving satellite based positioning system signals; d) processing said satellite based positioning system signals to extract satellite based positioning system intermediate location data; and e) reconciling said satellite based positioning system intermediate location data with a previously computed location of said moveable object.

4. The method of claim 3, wherein said reconciling reconciles said satellite based positioning system intermediate location data with both said location of said short range wireless base station and with a previously computed location of said moveable object to determine an updated location of said moveable object.

5. The method of claim 3, wherein said reconciling reconciles first said satellite based position system intermediate location data with a previously computed location of said movable object and then the result of said first reconciling with said

location of said short range wireless base station to determine an updated location of said moveable object.

6. The method of claim 3, wherein said processing includes correlating

said satellite based positioning system signals, and wherein said satellite based positioning system intermediate location data include results of said correlating.

7. The method of claim 3 , further comprising the step of: f) transmitting said updated object location to a third party.

8. The method of claim 8, wherein said transmitting is activated in response to an emergency.

9. The method of claim 3 .further comprising the step of: f) displaying said updated object location.

10. The method of claim 3 wherein said processing of said satellite based positioning system signals to extract satellite based positioning system intermediate location data is effected in real time by steps including:

(i) digitizing said received satellite based positioning system signal;

(ii) performing correlation computations on said digitized signal.

11. The method of claim 3, wherein said processing of said satellite based positioning system signals to extract satellite based positioning system intermediate location data is effected off line by steps including:

(i) digitizing said received satellite based positioning system signal;

(ii) storing said digitized signal, and

(iii) performing correlation computations on said stored signal.

12. A cellular phone with a location detector function, comprising: a) at least one antenna for receiving satellite based positioning system signals

and short range wireless communication system signals; b) a first mechanism for receiving satellite based positioning system signals from said at least one antenna and calculating satellite based positioning system intermediate location data based on said satellite based positioning system signals; and c) a second mechanism for receiving short range wireless communication system signals from said at least one antenna, wherein said received signal contains a substitute location of the cellular phone.

13. The apparatus of claim 12, further comprising: d) a third mechanism for transmitting location information connected to said satellite based positioning system intermediate location data and said substitute location.

14. The apparatus of claim 13, wherein said at least one antenna is used for transmitting said information via a cellular channel and wherein said third mechanism

includes:

(i) a microcontroller for controlling the cellular phone; and

(ii) a mobile RF radio for transmitting said information via said at least one antenna.

15. The apparatus of claim 12, wherein said first mechanism includes:

(i) a satellite based positioning system RF radio for receiving signals from said at least one antenna; and

(ii) a satellite based positioning system application specific integrated circuit for calculating said satellite based positioning system intermediate location data based on said received signals.

16. The apparatus of claim 15, wherein said first mechanism further includes: (iii) a digital signal processor for reconciling said satellite based positioning system intermediate location data with a previously computed location of said cellular phone.

17. The apparatus of claim 12, wherein said first mechanism includes:

(ii) a digital signal processor for calculating said satellite based positioning system intermediate location data based on said received signals.

18. The apparatus of claim 12, wherein said second mechanism includes:

(i) a short range wireless system RF radio for receiving signals from said at least one antenna;

(ii) a short range wireless system application specific integrated circuit for receiving said substitute location of the cellular phone from said short range wireless system RF radio.

19. A cellular phone with a location detector function comprising: a) An integrated RF radio including mobile RF functionality, satellite based positioning system RF functionality and short range wireless system RF functionality; and b) at least one antenna, for receiving satellite based positioning system signals, and short range wireless communication system signals, operationally connected to said integrated RF radio.

20. The apparatus of claim 19, further comprising: c) an integrated digital signal processor, operationally connected to said integrated RF radio.

21. The apparatus of claim 19, further comprising: d) an integrated microcontroller, acting as a wireless communication system digital modem, operationally connected to said integrated digital signal processor.