Method and apparatus for wireless network hybrid positioning

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DESCRIPTION

Method and apparatus for the hybrid location of wireless networks FIELD OF THE INVENTION

[1] The invention relates to position determination systems and, more particularly, to the hybrid location using wireless communication signals.

BACKGROUND

[2] To perform the location of positions in wireless cellular networks (for example, a cellular telephone network), several approaches perform trilateration, based on the use of timing information sent between each of several base stations and a mobile device , such as a cell phone. An approach, called Advanced Direct Link Trilateration (AFLT) in the CDMA or Observed and Improved Temporary Difference (EOTD) in the GSM or Observed Temporary Arrival Difference (OTDOA) in the WCDMA, measures the relative arrival times on the mobile device of the signals transmitted from each of several base stations. These moments are transmitted to a location server (for example, a position determination entity (PDE) in the CDMA), which calculates the position of the mobile device using these reception moments. The transmission moments in these base stations are coordinated in such a way that, at a particular time, the hours of the day associated with multiple base stations are within a specified error rate. The exact positions of the base stations and the reception moments are used to determine the position of the mobile device.

[3] Figure 1 shows an example of an AFLT system in which the reception moments (TR1, TR2 and TR3) of the signals from the cell base stations 101, 103 and 105 in the mobile cell phone 111 are measured. This timing data can then be used to calculate the position of the mobile device. Such calculation can be performed on the mobile device itself, or on a location server if the timing information obtained in this way by the mobile device is transmitted to the location server through a communication link. Usually, reception moments are communicated to a location server 115 by one of the cellular base stations (for example, the base station 101, or 103 or 105). The location server 115 is coupled to receive data from the base stations via the mobile switching center 113. The location server may include a base station calendar server (BSA), which provides the location of the base stations and / or the coverage area of ​​the base stations. Alternatively, the location server and the BSA server can be separated from each other; and the location server communicates with the base station to obtain the base station calendar for position determination. The mobile switching center 113 provides signals (eg, voice communications) to and from the landline public switched telephone network (PSTN), so that the signals can be transported to and from the mobile phone to other phones (by for example, landline phones in the PSTN or other mobile phones). In some cases, the location server may also communicate with the mobile switching center through a cellular link. The location server can also monitor emissions from several of the base stations, in an effort to determine the relative timing of these emissions.

[4] In another approach, called Uplink Arrival Moment (UTOA), the reception times of a signal from a mobile device are measured at several base stations (for example, measurements made at base stations 101, 103 and 105 ). Figure 1 applies to this case if the arrows of TR1, TR2 and TR3 are reversed. This timing data can then be communicated to the location server to calculate the position of the mobile device.

[5] A third further procedure for performing position location involves the use in the mobile circuit device for the Global Location Satellite System (GPS) of the United States or other Satellite Location Systems (SPS), such as the Russian GLONASS system and the proposed European Galileo system, or a combination of satellites and pseudolites. Pseudolites are ground-based transmitters, which broadcast a PN code (similar to a GPS signal) modulated in an L-band carrier signal, synchronized, in general, with the SPS time. Each transmitter can be assigned a unique PN code to allow identification by a mobile device. Pseudolites may be useful in situations where SPS signals from an orbiting satellite may not be available, for example, in tunnels, mines, buildings, buildings or other enclosed areas. The term "satellite", as used herein, is intended to include pseudoliths or equivalent of pseudolites and the term "GPS signals", as used herein, is intended to include GPS type signals from pseudolites or equivalent of pseudolites. The procedures that use an SPS receiver to determine a position of a mobile station can be fully autonomous (in which the SPS receiver, without any help, determines the position of the mobile station) or can use the wireless network to provide data of help or to participate in the calculation of the position. Examples of such procedures are described in US Patents 6,208,290; 5,841,396; 5,874,914; 5,945,944; and 5,812,087. For example, the

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US Patent No. 5,945,944 describes, among other things, a method for obtaining accurate time information from cell phone transmission signals, which is used in combination with SPS signals to determine the position of the receiver; U.S. Patent No. 5,874,914 describes, among other things, a method for transmitting the Doppler frequency shifts of the visible satellites to the receiver on the mobile device through a communication link to determine the position of the mobile device ; US Patent No. 5,874,914 describes, among other things, a method for transmitting satellite calendar data (or ephemeris data) to a receiver through a communication link to help the receiver determine its position; U.S. Patent No. 5,874,914 also describes, among other things, a method for tuning a precision carrier frequency signal from a cell phone system to provide a reference signal at the receiver for SPS signal acquisition. ; US Patent No. 6,208,290 describes, among other things, a method of using an approximate location of a receiver to determine an approximate Doppler to reduce the processing time of the SPS signal; and, U.S. Patent No. 5,812,087 describes, among other things, a method for comparing different records of a received satellite data message to determine a time in which one of the records is received at a receiver to determine the receiver position. In low-cost practical implementations, both the mobile cellular communications receiver and the SPS receiver are integrated into the same enclosure and can, in fact, share common electronic circuits.

[6] In yet another variation of the above procedures, the round trip delay (RTD) is found for signals that are sent from the base station to the mobile device and then returned. In a similar but alternative procedure, the round trip delay is found for the signals that are sent from the mobile device to the base station and then returned. Each of these round-trip delays is divided by two to determine an estimate of the unidirectional propagation delay. Knowledge of the location of the base station, plus a unidirectional delay, limits the location of the mobile device to a circle on the earth. Two such measurements from different base stations, then, result in the intersection of two circles, which in turn limits the location to two points on the earth. A third measurement (including an angle of arrival or a cellular sector identification) resolves the ambiguity.

[7] A combination of either the AFLT or the U-TDOA, with an SPS system, can be called a "hybrid" system. For example, U.S. Patent No. 5,999,124 describes, among other things, a hybrid system, in which the position of a cell-based transceiver is determined from a combination of at least: i) a time measurement representing a time of movement of a message, in the cell-based communication signals, between the cell-based transceiver and a communication system; and ii) a time measurement that represents a travel time of an SPS signal.

[8] The altitude aid has been used in various procedures to determine the position of a mobile device. The altitude aid is usually based on a pseudo-altitude measurement. The knowledge of the altitude of a location of a mobile device limits the possible positions of the mobile device to a surface of a sphere (or an ellipsoid) with its center located in the center of the earth. This knowledge can be used to reduce the number of independent measurements required to determine the position of the mobile device. For example, U.S. Patent No. 6,061,018 describes, among other things, a method in which an estimated altitude is determined from the information of a cell object, which may be a cell site having a transmitter. cell location in communication with the mobile device.

Attention is drawn to WO 03/010552 A which describes a procedure for determining the position of a transmitter located in the vicinity of a mobile communication device that can determine its position. The procedure comprising the steps of: (i) moving the mobile communications device to a plurality of reference locations; (ii) determine the position of the mobile communication device and the distance from the mobile communication device to the transmitter at each reference location; and (iii) determine the position of the transmitter using the corresponding positions and distances determined in step (ii). A procedure for determining the position of a mobile communications device using the above procedure is also described. Attention is also drawn to DE 101 42 954 A which describes a mobile phone location system that identifies base station service cells for different networks and measures the power received to calculate the mobile location with inter-network correlation.

Attention is also drawn to EP 1 215 928 A which describes a cellular radio system that operates to acquire the optimization of the radio network for a GSM environment by using a dual technology subscriber unit configured to exchange between a UMTS air interface mode and a slotted GSM mode. In GSM mode, system performance data is accumulated, that is, measurements, such as RX_Lev and BER, for a service cell and neighbors of the BA list and this GSM system performance data is communicated to a service OMC through a BSS and MSC. Simultaneously with the acquisition of GSM performance data, a UMTS call to the service Nodes B operating in the

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Continuous handover allows a service MSC or OMC to accurately identify the location of the subscriber unit through a triangulation process. A time reference obtained from the continuous transfer of a high bit rate data sequence allows the resolution of multiple paths in the UMTS domain, with an absolute multiplication path, therefore, obtainable from the time reference. The correlation, at the WTO level, of an identity of the subscriber unit associates the location of the subscriber with the performance data of the GSM system, thus allowing a processor in the WTO to accurately assess the performance of the GSM system with the objective of initiate, as necessary, the optimization of the radio network of the GSM system. Therefore, the need for costly drive tests of a GSM type system is avoided, which advantageously allows reconfiguration of the radio network either at the service operator's discretion or dynamically.

[9] WO 02/071781 A1 discloses another example of the prior art.

SUMMARY

[10] In accordance with the present invention, a method is provided for determining information about a wireless access point, a corresponding article and a mobile station, as set forth in the independent claims, respectively. Preferred embodiments of the invention are described in the dependent claims.

[11] In one aspect of the present invention, a method for determining information about a wireless access point includes: communicating between a server and one or more mobile stations through one or more first wireless access points of a first wireless network to determine the location of one or more mobile stations; collect data that specifies a plurality of locations from which wireless signals transmitted from a second wireless access point of a second wireless network are received by the one or more mobile stations in which the second wireless network is different from the first wireless network; and determine the location information on the second wireless access point from the data. The location information may include an estimated position of the second wireless access point. This estimated position of the second wireless access point can be determined from a weighted average of the plurality of locations; A weight for the weighted average may be based on the positioning information indicating a distance between a corresponding plurality of locations to the second wireless access point of the second wireless network. The positioning information may be an indicator of the level of the signal received for signals transmitted from the second wireless access point and received at a mobile station in the corresponding one of the plurality of locations. In an exemplary implementation, the location information includes a coverage area of ​​the second wireless access point and an estimated position of the second wireless access point that is determined from the coverage area of ​​the second wireless access point. In certain exemplary implementations, positioning information such as intervals that specify distances between each of the plurality of locations and the second wireless access point of the second wireless network may be additionally collected; and, the location information includes an estimated position of the second wireless access point, which is determined from the distance information and the data collected.

[12] In another aspect of the present invention, a method for determining information about a wireless network includes: collect data specifying a plurality of mobile station locations where wireless signals transmitted from a first wireless access point of a first wireless network are received during the determination of the plurality of locations, mobile stations receiving signals from the first wireless access point and also communicating signals between the mobile stations and at least a second wireless point of a second wireless network that is different from the first wireless network; and determine a location of the first wireless access point from a coverage area defined by the plurality of locations. In an example of this procedure, the statistics of any mobile station in an area where wireless signals transmitted from the first wireless access point during position determination can be received are determined. The location of the wireless access point can be determined from a weighted average of the plurality of locations; and a weighting for the weighted average is based on an indicator of the level of the signal received for the signals transmitted from the wireless access point and received by a mobile station in a corresponding one of the plurality of locations. The first wireless access point may operate in accordance with a standard for a wireless local area network (for example, IEEE 802.11).

[13] In another aspect of the present invention, a method for a mobile station of a position determination system includes: determining, at the mobile station, the first identification information of a first wireless access point of a first network wireless; determining the information of the first position that refers to a first position of the mobile station in a signal coverage area of ​​the first wireless access point; and communicate the first data indicating a correlation between the first identification information and the first position information from the mobile station to a server that is remote from the first wireless access point. The communication is done through a second point

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Wireless access from a second wireless network that is different from the first wireless network. In an example of this procedure, the information of the first position indicates a distance between the first position of the mobile station and a position of the first wireless access point, and this information of the first position is determined and transmitted as part of the first data. The information of the first position may be an indication of a signal level for signals that are transmitted from the first wireless access point and that the mobile station receives in the first position. Alternatively, the information of the first position may be a real position (for example, one determined through a GPS "fix"). The information of the first position may include one of: a) a measurement of a distance between the first position of the mobile station and the position of the first wireless access point; b) a measurement of a time delay in the transmission of the signal from the first wireless access point to the mobile station in the first position; and c) a measurement of a round trip time delay for the transmission of the signal between the first wireless access point and the mobile station in the first position. In one example, the first wireless access point is an access point of a local area network (for example, an IEEE 802.11 wireless LAN); and, the first identification information includes a Media Access Control (MAC) address. In one example, the first wireless access point supports bidirectional communication. In one example, signals from the Satellite Positioning System (SPS) of at least one SPS satellite are received to determine the first position information (which may include a pseudo distance measurement to an SPS satellite).

[14] In one example, the first data is communicated to the server through the first access point. In another example, the first data is communicated to the server through a second wireless access point, where the first wireless access point is an access point of a local area network and the second wireless access point is a base station mobile. In one example, the mobile station further determines: i) the second identification information of a second wireless access point, and ii) the information of the second position indicating a second position of the mobile station in a signal coverage area of the second wireless access point; and then, the second data indicating a correlation between the second identification information and the second position is communicated from the mobile station to the server. In one example, the first and second data is communicated from the mobile station to the server through a cellular base station. In one example, the mobile station determines the second identification information of another wireless access point and communicates the second identification information from the mobile station to the server to determine a second position of the mobile station in a signal coverage area of ​​the second wireless access point; where the first and second wireless access points can be the same access point (for example, both the first data and the second identification are communicated from the mobile station to the server through a cellular base station).

[15] The present invention includes methods and apparatus that perform these procedures, including the data processing systems that perform these procedures, and computer-readable media that, when executed in the data processing systems, cause the systems to carry Perform these procedures. In addition, the inventions described herein may be implemented in different nodes within a system, such nodes including a mobile station, a base station (such as a wireless access point) or a location server or other nodes in a network. or a wireless network.

[16] Other features of the present invention will be apparent from the accompanying drawings and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[17] The present invention is illustrated by way of example and not limitation in the figures of the attached drawings, in which the same references indicate similar elements.

Figure 1 shows an example of a prior art cellular network that determines the position of a mobile cellular device.

Figure 2 shows an example of a server that can be used with the present invention.

Figure 3 shows a block diagram representation of a mobile station according to an embodiment of the present invention.

Figure 4 shows an example of a hybrid location system according to an embodiment of the present invention.

Figure 5 shows another example of a hybrid location system according to an embodiment of the present invention.

Figure 6 illustrates a procedure for determining the position of a wireless access point in accordance with an embodiment of the present invention.

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Figure 7 illustrates another method for determining the position information of a wireless access point in accordance with an embodiment of the present invention.

Figure 8 shows a hybrid position determination procedure using a plurality of wireless networks in accordance with an embodiment of the present invention.

Figure 9 shows a hybrid position determination procedure using two wireless networks for communication with a server, in accordance with an embodiment of the present invention.

Figure 10 shows a procedure for generating location information about a wireless access point, in accordance with an embodiment of the present invention.

Figure 11 shows a hybrid position determination procedure using a wireless network for communication and another wireless network for the measurement of location parameters, in accordance with an embodiment of the present invention.

Figure 12 is a flow chart showing another embodiment of the invention.

Fig. 13 is a flow chart showing another embodiment according to the invention.

Figure 14 is a flow chart showing another embodiment of the invention.

DETAILED DESCRIPTION

[18] The following description and drawings are illustrative of the invention and should not be construed as limiting the invention. Numerous specific details are described to provide a thorough understanding of the present invention. However, in certain cases, already known or conventional details are not described in order to avoid obscuring the description of the present invention. References to one embodiment in the present disclosure are not necessary for the same embodiment; and said references refer to at least one.

[19] The recent development of wireless communication technologies leads to the implementation of several different wireless networks with significant overlapping coverage in some areas. In the present application, a wireless network refers to a set of wireless access points (for example, base stations) with the same air interface, operated by a service provider (for example, Verizon Wireless or Sprint), so that a mobile unit can access the network, through one among the set of wireless access points, when it is in the network coverage area; and the union of the coverage areas of the wireless access points of the wireless network is the coverage area of ​​the network. In addition, data communication refers to the transmission of data in a two-way communication system, although, in certain embodiments, the data communication may be a unidirectional communication or may include extracting information incorporated into a signal that is emits, regardless of whether the receiver needs it or not. A wireless access point may be considered to be a cellular tower or a base station or other wireless transmitter or receiver that is coupled to a network of other nodes (for example, the wireless access point is coupled by wireless line or cable to the other nodes).

[20] In certain areas, especially urban metropolitan areas, different wireless networks have essentially overlapping coverage. For example, different service providers may offer the same type of wireless service (for example, cell phone communication) in the same area. In addition, different types of wireless services, such as wireless telephony services (for example, mobile telephony services for data, voice or both) and wireless digital communications services (for example, wireless local area networks, such as networks Wi-Fi, Bluetooth, ultra-broadband), may overlap in the coverage area. For example, the access points of a wireless LAN (Local Area Network) (for example, for a wireless network based on the IEEE 802.11 standard) may be located within the coverage areas of wireless telecommunications networks (for example , based on the Standards of the Industrial Telecommunications Association (TIA) / Alliance of Electronic Industries (EIA), such as IS-95, IS-856 or IS-2000), such as those based on TDMA (Multiple Access by Time Division), GSM (Global System for Mobile Communications), CDMA (Multiple Access by Code Division), W-CDMA (Multiple Access by Band Code Division Wide), the UMTS (United Mobile Telecommunications System), the tD-SCdMA (Multiple Access by Synchronous Code Division and Time Division), the iDEN (Integrated Digital Enhanced Network), the HDR (High Data Rate) or others similar cellular networks.

example of the example of the example of the

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[21] At least one embodiment of the present invention seeks an integral system that supports location using these disparate sources of wireless signals to determine measurements and to obtain help information (eg, position and area of coverage of an access point, Doppler frequency shifts for visible SPS satellites, SPS ephemeris data) to form a flexible and ubiquitous navigation solution. In this comprehensive system, when information about an access point (for example, the calendar of base stations, such as the location and coverage area of ​​the base station) is available, it is used and can be improved. Where it is not, the system can automatically collect and enhance this information for the benefit of future location attempts.

[22] At least one embodiment of the present invention uses wireless signals transmitted from access points of more than one wireless network to combine information, such as SPS observations, wireless network observations, land elevation information and others, to get a position solution for a mobile station. In an embodiment of the present invention, a mobile station of a hybrid position system transfers information through access points of more than one wireless network (in bidirectional communication) to aid in the acquisition of SPS signals, the chronological sealing for measurements and other operations at the mobile station. In an embodiment of the present invention, a mobile station of a hybrid position system makes measurements using signals from the access points of different wireless networks, communicating at the same time with a remote server, using one or more of the wireless networks .

[23] Typically, information describing the identification, location and coverage area of ​​the sectors of a wireless network is stored in a base station calendar, which has been used in a hybrid location system using a single wireless network . However, when different wireless networks (for example, different service providers or different types of networks) have overlapping coverage, a typical mobile station does not have access to such information for the access points of the different wireless networks, even though the signals Wireless transmitted from the access points of the different wireless networks are on the air and available for the mobile station. This is generally because it is allowed, or authorized, that the mobile station has access to a wireless network, but not to another wireless network. A simple example of this is a cell phone that has been authorized access to a first wireless network (for example, a cell phone network operated by a service provider such as Verizon Wireless), but which has not been authorized to access to a second wireless network (for example, the Sprint cellular telephone network) or to a third wireless network (for example, a Wi-Fi hotspot).

[24] In one embodiment of the present invention, when available, information from small and localized transmitters, such as an access point of the wireless LAN network of the IEEE 802.11 standard, is incorporated into the wireless navigation solution . In many cases, the location information for these transmitters is not well known. In some cases, the "calendar" information describing the physical characteristics of a wireless network (for example, identifier, location and coverage area of ​​access points) is not available to users who wish to use it. Some network providers may choose not to share such information, while others may not have it available. In one embodiment of the present invention, the information to obtain the physical characteristics of a network is collected from mobile stations using another wireless network for communication. In an embodiment of the present invention, using the wireless signals available on the air from different wireless networks, and the capabilities of the mobile station for position determination (for example, a cell phone with a GPS receiver or with a part of a GPS receiver), mobile stations collect information about the access points of the different wireless networks that, in general, they may not be under the control of an operator of a wireless network through which mobile stations usually perform data communication. The information collected is used to obtain location information (for example, location and coverage area) about access points, which can be used to assist in determining hybrid positions for future position determinations.

[25] In one embodiment of the present invention, the signals that are used to provide time information and / or frequency information to a mobile station are not the same as that on which communication transactions are carried out. of data.

[26] A mobile station that supports multiple wireless communication interfaces (for example, IEEE 802.11 [and other IEEE 802 standards such as 802.15, 802.16 and 802.20], Bluetooth, UWB [Ultra Wide Band], TDMA, GSM, CDMA , W-CDMA, UMTS, TD-SCDMA, IDEN, HDR or other similar networks) is used in an embodiment of the present invention to use multiple wireless networks. Such a mobile station may have, for example, several different parts in a communication section that supports the transmission and / or reception of data for these different communication interfaces. Therefore, one part can manage the transmission and / or reception of Wi-Fi signals (for example, from IEEE 802.11 or 802.16) and another part of the communication section can support a cell phone interface such as a CDMA interface This also gives the user alternative communication channels, from which to choose when deciding to communicate. For example, availability, coverage, cost, data rate and ease of use can be considered when choosing which communication path to use.

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[27] In one embodiment of the present invention, a first wireless network is used for communications and location, while a second wireless network is used for location and, optionally, communications. For example, each of these wireless networks could use a completely different air interface (for example, different TIA / EIA standards), such as an air interface that is for a typical wireless cell phone (for example, TDMA, GSM networks , CDMA, W-CDMA, UMTS, TD-SCDMA, IDEN, HDR or other similar cellular networks) or some other wireless air interface, such as IEEE 802.11, Bluetooth or UWB standards. A plurality of these wireless networks is used for location purposes, even when only one wireless network can be used for communications. The advantages of a hybrid approach, in accordance with at least some of the embodiments of the present invention, include: improved redundancy for a more fail-safe solution, greater location availability, better accuracy and faster time from solution.

[28] Figure 4 shows an example of a hybrid location system according to an embodiment of the present invention. In Figure 4, the mobile station 407 uses signals in the air, which are transmitted both from the wireless access point 403 of the wireless network A and from the wireless access point 405 of the wireless network B, for the determination of the position. In one embodiment of the present invention, the mobile station includes a receiver to receive SPS signals from the SPS satellites (for example, GPS satellites not shown in Figure 4). Timing measurements (for example, pseudo-distance, round trip time, signal arrival times, temporary signal arrival differences) based on wireless signals from one of the wireless networks A and B, or both (and the SPS signals), can be used to determine the position of the mobile station. It is understood that, in general, each of the wireless networks A and B includes a certain number of access points (for example, cellular base stations, such as wireless access points 403 and 405). Wireless networks A and B can use the same type of air interface, operated by different service providers, or they can operate with the same communication protocols, but at different frequencies. However, wireless networks A and B can also use different types of air interfaces (for example, TDMA, GSM, CDMA, W-CDMA, UMTS, TD-SCDMA, IDEN, HDR, Bluetooth, UWB, IEEE 802.11 or other similar networks), operated by the same service provider or by different service providers.

[29] In one embodiment of the present invention, position determination is performed on the location server 411 shown in the example depicted in Figure 4. Mobile station 407 communicates the information extracted from the observed SPS signals (for example, pseudo-distance measurements of the SPS, and a record of an SPS message for comparison, to determine a signal reception time) and the information extracted from the observed wireless signals (for example, the identification of an access point, temporary round-trip or one-way measurements between mobile station 407 and at least one of the wireless access points, and signal levels received) to the location server, through one of the wireless networks, such as the wireless network A (for example, when the mobile station is a subscriber of wireless network A, but not a subscriber of wireless network B). Servers 413 and 415 maintain the calendar data, respectively, for wireless networks A and B. This calendar data can simply be, in an exemplary implementation, a database that lists a latitude and longitude for each wireless access point that is specified by identification information (for example, MAC address or cell tower identifier, etc.). The location server 411 uses the information communicated from the mobile station and the data on the calendar servers 413 and 415 to determine the position of the mobile station. The location server 411 can determine the location of the mobile station in a certain number of different ways. You can, for example, retrieve, from servers 413 and 415, the locations of wireless access points 403 and 405, and use those locations and distance measurements, which indicate a distance between mobile station 407 and points 403 and 405, and the pseudo-distance measurements of the SPS and the ephemeris information of the SPS, for calculating a position of the mobile station 407. United States Patent No. 5,999,124 provides an analysis of how distance measurements can be combined from a single wireless network and SPS pseudo-distance measurements to calculate a mobile station's position. Alternatively, location server 411 can only use land distance measurements (or other types of measurements, such as signal strength measurements) to multiple wireless access points of multiple wireless networks, to calculate the position, if many can be done (for example, more than 3) of such distance measurements; In this case, there is no need to obtain pseudo-distances from the SPS or the ephemeris information from the SPS. If SPS pseudo-distances are available to SPS satellites, these pseudo-distances can be combined with the SPS ephemeris information, obtained either by the mobile station or by a set of GPS reference receivers, as described in U.S. Patent No. 6,185,427, to provide additional information in position calculations.

[30] Network 401 may include local area networks, one or more intranets and the Internet, for the exchange of information between the various entities. It is understood that servers 411, 413 and 415 can be implemented as a single server program, or different server programs, in a single data processing system or in individual data processing systems (e.g., maintained and operated by different providers of services).

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[31] In one embodiment of the present invention, different service providers operate the wireless networks A and B, which are used by the mobile station for position determination. A typical mobile station is a subscriber to only one of them and, therefore, the mobile station is authorized to use (and access to) a single wireless network. However, it is still often possible to receive at least signals from the wireless network to which it is not subscribed and, therefore, it is still possible to make distance measurements or signal strength measurements in relation to the wireless access points in the wireless network to which it is not subscribed. A specific example of this situation would involve a user of a tri-modal CDMA cell phone that can receive frequency band signals from PCS [Personal Communication Systems] (such as, for example, from the wireless network operated by Sprint, which it is a first service provider) and can also receive other CDMA signals on other frequencies (such as, for example, from the wireless network operated by Verizon Wireless, which is a second service provider). If the user has subscribed only to the Sprint wireless network, then the user's phone (a form of a mobile station) is authorized to operate with the Sprint wireless network, but not with the Verizon wireless network. The user can use the phone in an environment where only a Sprint wireless access point (for example, a Sprint cellular base station) is capable of radio communication with the user's phone, but in this environment there are numerous Verizon wireless access points that are within the radio communication range of the user's phone. In this context, it is still possible for the phone to obtain SPS support data (if desired) from a location server, through the Sprint wireless network, and transmit the SPS pseudo-distances, obtained in the phone, to the location server. However, it will not be possible to obtain more than one distance measurement to a wireless access point, unless distance measurements are obtained to the Verizon wireless access points. With one embodiment of the invention, the phone obtains distance measurements to the available Verizon wireless access points, thus providing at least a few distance measurements (for example, the distances between the telephone and two Verizon cellular base stations). ), which can be used in the position calculations that are performed to determine the position of the phone.

[32] Service providers keep calendar information on servers 413 and 415 separately. Although mobile station 407 has communication access to only one of the wireless networks, location server 411 can access both servers 413 and 415 for calendar data from base stations. After determining the identities of the base stations (for example, wireless access points 403 and 405) of both wireless networks A and B, mobile station 407 transmits the identifications of base stations to the location server 411, which uses the servers 413 and 415 to retrieve the corresponding positions of the base stations, which can be used in determining the position of the mobile station.

[33] Alternatively, cooperation between service providers to share calendar data is not necessary. For example, the operator of the location server 411 maintains both calendar servers 413 and 415 (for example, through a survey process to obtain the calendar data, or through a data collection process using mobile stations, which will be described in detail with figures 6 and 7 and 10).

[34] In one embodiment of the present invention, mobile station 407 uses both wireless networks A and B for communication with the location server (instead of using only one of the wireless networks for communication purposes). As is known in the art, various types of information can be exchanged between the mobile station and the location server for position determination. For example, the location server 411 may provide the mobile station 407 with Doppler frequency offset information for the satellites in view of the mobile station (for example, over the wireless network A); and the mobile station can provide pseudo-distance measurements for SPS signals, the identification information of the base stations and the associated distance measurements (e.g. round trip time measurements) to the location server, for calculation of the position of the mobile station (for example, over the wireless network B). In one embodiment of the present invention, a mobile station is capable of communicating through more than one wireless network with the location server when it is in the coverage area of ​​these wireless networks. However, the balance between cost and performance can dictate communication with the server using one of the wireless networks, using the other at the same time only for timing measurements (or other measurements, such as received signal levels) or for Assist in measurement, such as obtaining temporary information on wireless transmission from an access point for chronological stamp measurements (for example, to resolve ambiguity), or to couple to the precise carrier frequency of a wireless cellular base station, to calibrate the local oscillator of the mobile station.

[35] In one embodiment of the present invention, the location of the mobile station is determined on the location server using the information communicated from the mobile station and then transmitted back to the mobile station. Alternatively, the position calculation can be performed on the mobile station using the assistance information from the location server (for example, frequency shifts of

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Doppler for visible satellites, positions and coverage areas of access points, differential GPS data and altitude help information).

[36] Figure 5 shows another example of a hybrid location system according to an embodiment of the present invention. An access point of a wireless network (for example, cellular base station 503) is used for communication between mobile station 507 and location server 511. A method for determining the position of the mobile station 507 can use SPS signals (for example, from satellite 521), wireless signals from the access points (for example, the cellular telephone base station 503) of the wireless network used for data communication, as well as wireless signals from the access points of other wireless networks, such as those from access point B (505), which may be a base station of a different wireless cellular telephone network (for example, operated by a different service provider, or that uses a different air interface), and from access point A (509), which may be a Wireless LAN access point (for example, a Bluetooth access point or a Wi-Fi wireless access point).

[37] Generally, an access point of a wireless LAN (or other similar low power transmitters) has a small coverage area. When available, the small coverage area of ​​such an access point provides a very good estimate of the location of the mobile station. In addition, wireless LAN access points are usually located near or inside buildings, where the availability of other types of signals (for example, SPS signals or wireless telephony signals) may be low. Therefore, when such wireless transmissions are used with other types of signals, the performance of the location system can be greatly improved.

[38] In one embodiment of the present invention, the wireless signals of different wireless networks are used for position determination. For example, wireless signals from different wireless networks can be used to determine the identities of the corresponding access points, which are then used to determine the locations and coverage areas of the corresponding access points. When precision distance information is available (for example, round trip time or signal travel time between an access point and the mobile station), the distance information and the location of the access point can be used in obtaining a hybrid location solution. When approximate distance information is available (for example, the level of received signal, which can be approximately correlated with an estimated distance), the location of the access point can be used to estimate the position of the mobile station (or determine the estimated altitude of the mobile station). In addition, the mobile station may use the precision carrier frequency from one of the wireless networks (for example, from the access point 505 or 509), which may not be the one used for the purpose of data communication, to calibrate the local oscillator of the mobile station. More details on the precision carrier frequency coupling of a wireless signal can be found to provide a reference signal to an SPS receiver for signal acquisition, in US Patent No. 5,874,914. In addition, the mobile station may use the precise temporal information in the wireless signals from one of the wireless networks (for example, from the access point 505 or 509), which may not be used for the purpose of data communication . More details on the use of accurate time information (e.g., timing markers, or system time) for chronological sealing can be found in U.S. Patent No. 5,945,944.

[39] Since some of the access points of the different wireless networks do not have data from

well-known calendar (for example, the position of the wireless access point, the coverage area of ​​the wireless access point), an embodiment of the present invention obtains the calendar data of the information collected from the mobile stations. Figure 6 illustrates a procedure for determining the position of a wireless access point in accordance with an embodiment of the present invention. In Figure 6, a location server does not know the position of the access point antenna 601. For the calculation of the position of the access point, the location server correlates the positions of one or more mobile stations and their distances corresponding to the access point, which are obtained from the mobile stations while performing the position determination for the stations mobile phones For example, a mobile station at position L1 (611) determines the distance R1 (613) to the access point antenna 601. The mobile station obtains measurements based on SPS signals (for example, pseudo-distance measurements of the SPS and extraction of ephemeris information from the SPS from the SPS signals) and to wireless transmissions (for example, distance measurements). The mobile station can calculate its position using the measurements and transmit to the location server the position calculated with: i) the distance to the antenna from the access point; and ii) the identity of the access point antenna. Alternatively, the mobile station can transmit: i) the measurements; ii) the distance to the antenna from the access point; and iii) the identity of the access point antenna, to the location server, which calculates the position of the mobile station using the measurements, and which stores the distance measurements (for example, R1, R2 and R3 and the corresponding positions (for example, L1, L2 and L3). When a certain number of data points are available, each of which correlates the position of a mobile station and the distance from the mobile station to the antenna of the access point, the location server determines the antenna position of the access point. It can be seen in Figure 6 that just three distance measurements (R1, R2 and R3) and their corresponding positions (L1, L2 and L3) are sufficient to

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Specify a particular location of the identified access point (shown at the intersection of three circles specified by the three distances). Various procedures, which have been used in the art to calculate the position of a mobile station based on distance information, can be used to calculate the position of the access point. Note that the data points can come from a single mobile station or from a certain number of mobile stations.

[40] In addition, the accumulated data points of mobile station locations show the coverage area of ​​the access point (for example, in a scatter plot of mobile locations). When the position of the access point is not known, the collected data points can be used to estimate the position and coverage of the access point. When an initial estimate of the position of the access point is available, the collected data points can be used to improve the estimate. The collection and improvement process can be an ongoing process during the location server service. Note that collection and enhancement operations can also be performed on a server other than the location server. For example, in an embodiment of the present invention, the collection and improvement operations are performed on the calendar server 513, which communicates with the location server 511 when performing the hybrid position determination for mobile stations.

[41] However, the accuracy information of the distance to some access points may not be available for mobile stations of a location server. Figure 7 illustrates another method for determining the position information of a wireless access point in accordance with an embodiment of the present invention. A larger number of data points (for example, 711, 713, 715, 721, 723, 725) of mobile station locations that can receive signals from the access point (for example, 703) define a coverage area ( for example, 705) of the access point (for example, using a scatter plot of places, the smallest circle that encloses the data points). From the coverage area, the location server can calculate an estimated position of the access point (for example, the geometric center of the coverage area). In addition, the distance information (for example, an indicator of the received signal level, a round trip time) can be used to define a weighting for the determination of the weighted average of the coverage area (for example, the closer of the access point, the higher the weighting), from which the estimated position of the access point is determined. In addition, in one embodiment, the location server determines the probability that a mobile station is in a particular location from the statistics of the mobile stations, provided that certain distance information is specified. Other information, such as the level of the wireless transmission signal from other transmitters, can then be used further to further reduce the possible locations of the mobile station.

[42] For example, a wireless LAN network access point is located inside building 701. While the sPs signals (for example, the satellite signals of the SPS 741-745) and the wireless cellular telephony signals (for example, the signals from the cellular base station 751) may be weak within the building 701, the position of a mobile station can be easily determined (for example, without using the signals from access point 703) in certain locations throughout the building (for example, locations 711-725, which may be just outside the building or at certain locations within the building, such as points near the windows). In an embodiment of the present invention, the identification of the access point is determined and sent to the server with the location of the mobile station (or information specifying the location of the mobile, such as pseudo-distances to the satellites at the view) for the determination of the coverage area (and / or position) of access point 703. The location information of the access point (for example, coverage area, position) can be kept on the server (or on a different server). When a mobile station is inside a building (or in a position near the building), where some of the SPS signals and cell phone signals are blocked, location information about the access point can be used to help determine the position of the mobile station.

[43] It is understood that some access points can be moved from one place to another. In one embodiment of the present invention, the server tracks the collected position information on one or more mobile stations receiving the transmission from an access point, in order to determine if the access point is displaced. For example, the server can compare the old coverage area with the recent coverage area (for example, by comparing the center and radius of the coverage area) to determine if the access point is displaced. Alternatively, the server may periodically discard old information in view of the recently collected information. In addition, the server can weigh the information collected so that the newly collected data provide more weight in determining the coverage area and / or the location of the access point and that the influence of previously collected data may eventually decrease with time. In addition, the server can determine if an access point moves frequently; and, if the access point moves frequently, the access point can be disqualified as a reference point for position determination. In addition, in one embodiment, when an access point has not been observed for a certain period of time, the access point is removed from the database; Similarly, when a new access point is observed, it is added to the database. In this way, the server can update the information on the access point continuously.

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[44] In at least one embodiment of the present invention, a mobile station can determine its position without a communication link. The mobile station has memory to store at least some of the information about the locations of the mobile station and the corresponding levels of received signals or distance measurements of a series of wireless access points (for example, for cell phone access , or for access to a wireless LAN). The mobile station transmits the data to a server when a communication link (for example, a cable connection through a communication port of the mobile station or a wireless connection through a transceiver of the mobile station) is available. As an alternative, the mobile station can directly use the stored information to obtain the position information on the access point in determining its own position when necessary.

[45] Figure 8 shows a general hybrid position determination procedure using a plurality of wireless networks in accordance with an embodiment of the present invention. In operation 801, a mobile station receives wireless signals transmitted from a plurality of wireless access points of different wireless networks (for example, wireless networks of different air interfaces, wireless networks of different service providers, wireless networks operating at different frequencies , wireless networks that use different communication protocols, etc.). In operation 803, the mobile station uses the wireless signals from each of the access points of the different wireless networks in determining the position of the mobile station (for example, to determine the identity of the access point, to block a local oscillator of the mobile station at a precision carrier frequency of a wireless signal, to obtain a timing indicator from a wireless signal, to determine the signal transmission delay between the mobile station and one of the access points or to communicate with a server). In general, the mobile station can use the wireless signals from the access points of different wireless networks to perform different operations, although the mobile station can use the wireless signals from the access points of some different wireless networks to carry out a series of similar operations. In operation 805, the mobile station communicates with a server to determine the position of the mobile station using at least one of the different wireless networks. Usually, the mobile station communicates with the server using only one of the different wireless networks; however, the mobile station can communicate with the server using more than one wireless network (for example, to transmit the time of reception at an access point for a signal transmitted from the mobile station, to transmit a round trip time or to transmit other information to or from a location server).

[46] Figure 9 shows a hybrid position determination procedure using two wireless networks for communication with a server, in accordance with an embodiment of the present invention. Operation 821 receives, in a mobile station, SPS signals transmitted from one or more SPS satellites and wireless signals transmitted from a plurality of wireless access points of more than one wireless network. The mobile station may use the wireless signals received from one or more wireless networks to assist in the acquisition of SPS signals (for example, to extract the Doppler frequency shifts for the satellites in sight of the mobile station, to calibrate the local oscillator of the mobile station, or to obtain a timing indicator to chronologically seal a measurement). The mobile station uses the SPS signals to determine pseudo-distances to the visible satellites, and the mobile station uses wireless signals from the wireless access points to identify the access points and to make distance measurements to the access points wireless, for position determination. These received signals are usually transmitted from satellite transmitters and wireless access points, and are available for any mobile station that chooses to use them. Operation 823 communicates first information (for example, a record of an SPS message) between the mobile station and a server, using an access point of a first wireless network (for example, a wireless local area network). Operation 825 communicates a second information (e.g., Doppler frequency shifts, ephemeris data for SPS satellites in sight) between the mobile station and a server using an access point of a second wireless network (e.g., a wireless cell phone network). Operation 827 determines the position of the mobile station from the communication of the first information and the second information. In general, availability, coverage, cost, data rate and ease of use are considered when choosing which communications path to use. In addition, the mobile station can use different communication paths in different locations. For example, when the mobile station is within the coverage area of ​​a wireless LAN (for example, a home network), the mobile station can use the wireless LAN (for example, over the Internet) to communicate with the server in search of information that does not need to pass through the base station of a wireless cellular telephone system (eg, Doppler frequency shifts); and use the base station of the wireless cell phone system to transmit information that is related to the base station (for example, the round trip time measurement to the base stations of the wireless cell phone system). In another example, the mobile station may choose to use either the wireless cell phone system or the wireless LAN for communication, according to the cost of communication and availability. In an embodiment of the present invention, the mobile station automatically determines the communication path according to a set of rules

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(for example, availability, cost, priority and others) that can be specified by a user of the mobile station or that can be set as a default configuration by one of the wireless networks.

[47] Figure 10 shows a method for generating location information about a wireless access point, in accordance with an embodiment of the present invention. Operation 841 detects, on a mobile station, wireless signals transmitted from a wireless access point (for example, a wireless access point that conforms to the IEEE 802.11 standard for a wireless local area network, or other types of transmitters land-based wireless transmitting signals with their identification data). Note that, in the present application, the wireless access points do not include satellite-based transmitters. Operation 843 determines identification information, which may be a unique identifier, of the wireless access point (for example, the MAC address of the wireless access point or an identifier of a cellular base station) from the wireless signals. Operation 845 determines the position of the mobile station (for example, on the mobile station or on a location server). For example, the mobile station can calculate the position based on pseudo-distance measurements and other distance information; or, the mobile station can transmit the pseudo-distance measurements and the distance information to a location server, which calculates the position of the mobile station (and the location server can send the calculated position back to the mobile station ). Operation 847 correlates the position of the mobile station with the identification information of the wireless access point. This correlation can be transmitted to a location server so that future mobile station location operations can use the position and identification information to determine a position of the identified wireless access point. Operation 849 generates location information about the wireless access point (for example, calendar of the access point, or statistics of the coverage area of ​​the wireless access point). Typically, correlation data is sent to a server (for example, a location server, or an access point calendar server) that generates location information about the access point based on a number of positions in one or more more mobile stations that report the reception of signals transmitted from the access point. Location information about the wireless access point can be obtained from a weighted average procedure, as described above (or other procedures, such as the use of distance information as shown in Figure 6). However, a mobile station can also track the correlation and obtain location information about the wireless access point (for example, from data points collected at different times of time). The location information on the wireless access point can then be used for position determination.

[48] ​​Figure 11 shows a hybrid position determination procedure using a wireless network for communication and another wireless network for measuring location parameters, in accordance with an embodiment of the present invention. Operation 861 detects, on a mobile station, wireless signals transmitted from a wireless access point (for example, a wireless access point that conforms to the IEEE 802.11 standard for a wireless local area network, or a base station of cellular communication) of a first wireless network (for example, a wireless local area network, or a cellular telephone communication system). Operation 863 determines the identification information of the wireless access point (for example, the MAC address, or the Base Station Identifier) ​​from the wireless signals. Operation 865 retrieves location information about the wireless access point (for example, calendar of the access point), using the identification information. For example, the mobile station may transmit identification information of the wireless access point to the location server, which retrieves the location information on the wireless access point using the identification information (for example, from a database, or from another server, such as an access point calendar server). In another example, the mobile station maintains the location information about the wireless access point in memory; thereby, location information is simply extracted from the memory of the mobile station. Operation 867 determines the position of the mobile station using the location information and using a communication link between the mobile station and a wireless access point of a second wireless network (for example, a cellular telephone network). For example, satellite assistance data (for example, Doppler frequency shifts) for the acquisition of SPS signals or timing measurements (for example, pseudo-distances or time of SPS signal arrivals) are communicated to via the second wireless network to determine the position of the mobile station.

[49] Figure 12 shows another example procedure of the inventions. In this procedure, a mobile station receives, in operation 901, the first signals transmitted from a first wireless access point of a first wireless network. The first wireless network can support bidirectional communication between the various nodes within the first wireless network, as well as the nodes outside this network. In operation 903, at least one distance measurement is determined using the first signals. If additional signals from other wireless access points of the first wireless network are also available, then additional distance measurements to these other wireless access points (and their identification information) are obtained. In an alternative implementation of operation 903, another measurement (for example, a signal strength measurement of the first signals) can be taken by the mobile station without attempting to make a distance measurement using the first signals. In a

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As an example, a travel time of the first signals from the first wireless access point to the mobile station is measured and an identification of this first wireless access point is received from the first wireless access point. In operation 905, the second signals communicate between the mobile station and a second wireless access point of a second wireless network, which is different from the first wireless network. The mobile station may, in this operation, receive the second signals (which may include SPS assistance data, etc.) from the second wireless access point. In operation 907, the mobile station and the server communicate to determine the position of the mobile station, and this communication may be through the second wireless access point. For example, the mobile station may, in operation 907, transmit the distance measurements and identification information, performed in operation 903, and the pseudo-distances of the SPS, obtained by the mobile station, to the server, through the Second wireless access point. The identification information is used to obtain the location of the wireless access points for which the distance measurements (or other measurements) were obtained, and the server can then determine the position of the mobile station using at least some of the measurements available (for example, pseudo-distances from the SPS to SPS satellites and distance measurements, or other measurements, to several terrestrial wireless access points). Alternatively, the mobile station can determine its position (rather than the server) using the distance and pseudo-distance measurements of the SPS, and using the information provided by the server (such as the location of the wireless access points identified, in one of the wireless networks, or both).

[50] The first wireless network in Figure 12 may be a wireless local area network and, in this case, the first wireless access point may be a wireless router that operates in accordance with a Wi-Fi standard. Alternatively, the first wireless network may be a wireless cell phone network operated by a first service provider, and the second wireless network may be another (different) wireless phone network operated by a second service provider, and the station mobile, which can be a cell phone with an integrated GPS receiver, is authorized to work only with the second wireless network and not with the first wireless network. Several other alternatives, discussed in this document, can also be applied to this example in Figure 12.

[51] Figure 13 is another example of a process of the inventions. In this example, the mobile station, in operation 931, obtains identification information of a first wireless access point of a first wireless network that is accessible (eg, within radio communication) for the mobile station. This identification can be a MAC address (for example, for a local area Ethernet network) or a cellular telephone base station identifier (for example, "cellular tower"). In operation 933, the mobile station transmits, through a second wireless access point of a second wireless network, the identification information to a server (for example, a location server) during a position determination operation. In this example, the second wireless network is different from the first wireless network (for example, different air interfaces, different service providers, etc.). Then, in operation 935, the server uses the identification information of the first wireless access point to determine the location of the first wireless access point (which may have been collected / collected by the procedures described herein, as in Figure 14). The server may also, in operation 935, use other data (eg, pseudo-distances from the SPS, determined on a GPS receiver that is integrated in the mobile station, and then transmitted to the server) to determine the position of the station mobile. The server can, for example, combine the pseudo-distances of the SPS with the measurements on signals from the wireless access points, to determine the position of the mobile station. Alternatively, the pseudo-distances of the SPS can be combined with the known locations of the wireless access points (in particular, in the case of wireless LANs that have shorter signal distances). In another alternative to operation 935, the server may provide assistance data (for example, the location of the first wireless access point and possibly other data such as Doppler data for SPS satellites in view of the mobile station, etc.) to the mobile station, but the server does not calculate the position of the mobile station; rather, the mobile station performs the position solution using at least some of the available measurements (eg, pseudo-distances of the SPS, distance measurements or other measurements relative to the wireless access points of one of, or all, wireless networks available) and support data available from the server.

[52] Figure 14 shows another example procedure of the inventions. This procedure ultimately determines the positions of the wireless access points, so that future position determination operations for mobile stations can be performed using several wireless networks, as described herein. In operation 971, the data is collected. This data specifies a plurality of locations of mobile stations in which the wireless signals, transmitted from at least a first wireless access point of a first wireless network, are received during determinations of the plurality of locations. Mobile stations may, in operation 973, receive signals from the first wireless access points and also communicate signals between the mobile stations and at least a second wireless access point of a second wireless network (which is different from the first wireless network ). This communication with the second wireless network may be for the purpose of providing information that is used in the collection of the data used to determine

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the locations of wireless access points of the first wireless network. In operation 975, the location of at least the first wireless access point (for example, in the manner shown in Figure 6) is determined from the coverage area defined by the plurality of locations.

[53] Figure 2 shows an example of a data processing system that can be used as a server in various embodiments of the present invention. For example, as described in US Patent No. 5,841,396, the server (201) can provide assistance data such as Doppler, or other satellite assistance data, to the GPS receiver at a mobile station. In addition, or as an alternative, the same server, or a different server, can perform the calculation of the final position, instead of the mobile station (after receiving the pseudo-distances or other data from which you can determine the pseudo-distances from the mobile station) and then you can forward this position determination result to the base station or some other system. The data processing system, such as a server (for example, a location server, a calendar server), usually includes communication devices 212, such as modems or network interfaces. The location server can be coupled to a number of different networks through communication devices 212 (for example, modems or other network interfaces). Such networks include one or more intranets, the network, the cellular switching center or multiple cellular switching centers 225, the land-based telephone system switches 223, the cellular base stations (not shown in Figure 2), the receivers of the GPS 227 or other 221 location processors or servers.

[54] Multiple cellular base stations are usually arranged to cover a geographical area with radio coverage, and these different base stations are coupled to at least one mobile switching center, as is well known in the prior art (eg see Figure 1). Therefore, multiple base stations would be distributed geographically, but coupled to each other by a mobile switching center. The network 220 may be connected to a network of reference GPS receivers, which provide differential GPS information and can also provide GPS ephemeris data for use in calculating the position of mobile systems. The network is coupled through the modem, or other communication interface, to the processor 203. The network 220 can be connected to other computers or network components. In addition, the network 220 can be connected to computer systems operated by emergency operators, such as Public Security Response Points that respond to telephone calls to 911. Various examples of procedures for using a location server have been described in numerous patents. United States, including: US Patents 5,841,396; 5,874,914; 5,812,087 and 6,215,442.

[55] Server 201, which is a form of a data processing system, includes a bus 202 that is coupled to a microprocessor 203 and a ROM 207 and a volatile RAM 205 and a non-volatile memory 206. The processor 203 is coupled to cache 204 as shown in the example of Figure 2. Bus 202 interconnects these various components with each other. While Figure 2 shows that non-volatile memory is a local device directly coupled to the rest of the components in the data processing system, it will be appreciated that the present invention can use a non-volatile memory that is remote from the system, such as a network storage device that is coupled to the data processing system through a network interface such as a modem or an Ethernet interface. Bus 202 may include one or more buses connected to each other through various bridges, controllers and / or adapters, as is well known in the art. In many situations, the location server can perform its operations automatically without human assistance. In some designs where human interaction is required, the I / O controller 209 can communicate with displays, keyboards and other I / O devices.

[56] Note that, although Figure 2 illustrates various components of a data processing system, it is not intended to represent any particular architecture, or mode of interconnection of the components, since such details are not relevant to the present invention. It will also be appreciated that network computers and other data processing systems, which have fewer components or perhaps more components, can also be used with the present invention and can act as a location server or a PDE (position determining entity ).

[57] In some embodiments, the methods of the present invention can be performed in computer systems that are used simultaneously for other functions, such as cell switching, messaging services, etc. In these cases, some, or all, of the hardware in Figure 2 would be shared for several functions.

[58] It will be apparent from this description that aspects of the present invention can be realized, at least in part, in software. That is, the techniques can be carried out in a computer system or other data processing system in response to executing its processor sequences of instructions contained in the memory, such as ROM 207, volatile RAM 205, nonvolatile memory 206 , cache 204 or a remote storage device. In various embodiments, wired circuits may be used in combination with software instructions to implement the present invention. Therefore, the techniques are not limited to any specific combination of hardware and software circuits, or to any particular origin for the instructions executed by the data processing system. In addition, to

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Throughout this description, various functions and operations are described as performed by, or caused by, software code, to simplify the description. However, those skilled in the art will recognize that what is understood by such expressions is that the functions result from the execution of the code by a processor, such as the processor 203.

[59] A machine-readable medium can be used to store software and data that, when executed by a data processing system, causes the system to carry out various procedures of the present invention. This executable software and data can be stored in several places, including, for example, ROM 207, volatile RAM 205, non-volatile memory 206 and / or cache 204, as shown in Figure 2. Parts of this software and / or data may be stored on any one of these storage devices.

[60] Therefore, a machine-readable medium includes any mechanism that provides (ie, stores and / or transmits) the information in a form accessible by a machine (eg, a computer, a network device, an assistant personal digital, a manufacturing tool, any device with a set of one or more processors, etc.). For example, a machine-readable medium includes recordable / non-recordable media (e.g., read-only memory (ROM), random access memory (RAM), magnetic disk storage media; optical storage media, flash memory devices , etc.), as well as electrical, optical, acoustic or other forms of propagated signals (for example, carrier waves, infrared signals, digital signals, etc.); etc.

[61] Figure 3 shows a block diagram representation of a mobile station according to an embodiment of the present invention. The mobile station includes a portable receiver, which combines a communication transceiver with the GPS receiver for use in an embodiment of the present invention. The combined mobile unit 310 includes circuits to perform the functions required to process GPS signals, as well as the functions required to process communication signals received through a communication link. The communication link, such as the communication link 350 or 360, is usually a radio frequency communication link to another component, such as the base station 352 having the communication antenna 351, or the wireless LAN access point 362 with antenna 361. Although Figure 3 illustrates an embodiment in which the communication antenna 311 is used to receive signals from the different types of wireless access points (for example, from the access point 362 for wireless LAN and from the base station 352 for cellular telephone service), the combined receiver can use individual and different antennas for the reception of signals from different aerial interfaces. In addition, the combined receiver may use individual and distinct components for at least partial processing of the received wireless signals, and may or may not share some components in the processing of the wireless signals of different aerial interfaces. For example, the combined receiver may have separate circuits for processing RF signals and share the same data processor resources. From this description, various combinations and variations of the combined receptor will be apparent to one skilled in the art.

[62] The portable receiver 310 is an example of a GPS receiver combined with a communication receiver and transmitter. The receiver and communication transmitter can be implemented as multiple receivers and transmitters for different wireless networks. For example, communication transceiver 305 may include a transceiver part for the reception and / or transmission of cell phone signals and another transceiver part for receiving and / or transmitting Wi-Fi signals. The receiver 310 contains a GPS receiver stage that includes the acquisition and tracking circuit 321 and the communication transceiver section 305. The acquisition and tracking circuit 321 is coupled to the GPS antenna 301, and the communication transceiver 305 is coupled to communication antenna 311. The GPS signals (for example, the signal 370 transmitted from the satellite 303) are received through the GPS antenna 301, and enter the acquisition and tracking circuit 321 that acquires the PN (Pseudo-random noise) codes to the different satellites received. The data produced by circuit 321 (for example, correlation indicators) are processed by processor 333 for transmission (for example, from the pseudo-distances of the SPS) by transceiver 305. The communication transceiver 305 contains a transmission / reception switch 331, which routes the communication signals (usually, from RF) to and from the communication antenna 311 and the transceiver 305. In some systems, a band split filter, or "duplexer", is used instead of the T / R switch. The received communication signals are entered into the communication receiver 332 and passed to the processor 333 for processing. The communication signals to be transmitted from the processor 333 are propagated to the modulator 334 and the frequency converter 335. The power amplifier 336 increases the signal gain to a level suitable for transmission to the base station 352 (or to the point of wireless LAN access 362).

[63] In one embodiment of the present invention, the communication transceiver section 305 is capable of being used with a number of different aerial interfaces (for example, IEEE 802.11, Bluetooth, UWB, TD-SCDMA, IDEN, HDR, TDMA, GSM, CDMA, W-CDMA, UMTS or other similar networks) for communication (for example, through communication links 350 and 360). In one embodiment of the present invention, the communication transceiver section 305 is capable of being used with an aerial interface for the

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communication, and is capable of being used to receive signals with other aerial interfaces. In an embodiment of the present invention, the communication transceiver section 305 is capable of being used with an air interface for communication, being able, at the same time, to be used with signals on another air interface to extract the indicators of timing (for example, timing frames or system time) or to calibrate the local oscillator (not shown in figure 3) of the mobile station. More details about the mobile station to extract timing indicators or calibrate the local oscillator can be found in US Patents 5,874,914 and 5,945,944.

[64] In an embodiment of the combined GPS / communication system of the receiver 310, the data generated by the acquisition and tracking circuit 321 is transmitted to a server, via the communication link 350, to the base station 352 or , via communication link 360, to the access point of wireless LAN 362. The server then determines the location of the receiver 310 based on the data from the remote receiver, the time at which the data was measured and the ephemeris data received from its own GPS receiver, or other sources of such data. Location data can be transmitted after return to receiver 310 or other remote locations. More details on portable receivers using a communication link can be found in U.S. Patent No. 5,874,914.

[65] In one embodiment of the present invention, the combined GPS receiver includes (or is coupled to) a data processing system (for example, a personal data assistant, or a laptop). The data processing system includes a bus that is coupled to a microprocessor and memory (for example, ROM, volatile RAM, non-volatile memory). The bus interconnects various components with each other and also interconnects these components to a display controller and display device, and peripheral devices, such as input / output (I / O) devices, which are well known in the art. The bus may include one or more buses connected to each other through various bridges, controllers and / or adapters, as is well known in the art. In one embodiment, the data processing system includes communication ports (for example, a USB port (Universal Serial Bus), a port for the IEEE-1394 bus connection). In one embodiment of the present invention, the mobile station stores the locations and identifications (for example, the MAC address) of wireless access points (for example, according to the types of wireless access points) for the extraction and improvement of location information about wireless access points, using memory and software program instructions stored in memory. In one embodiment, the mobile station only stores the locations of the mobile station and the identifications of the wireless access points for transmission to a server (for example, through a communication port, or a wireless communication link ) when a communication connection is established.

[66] Although the methods and apparatus of the present invention have been described with reference to GPS satellites, it will be appreciated that the descriptions are equally applicable to location systems using pseudolites or a combination of satellites and pseudolites. Pseudolites are ground-based transmitters that emit a PN code (similar to a GPS signal), usually modulated in an L-band carrier signal, generally synchronized with the GPS time. Each transmitter can be assigned a unique PN code to allow identification by a remote receiver. Pseudolites may be useful in situations where GPS signals from an orbiting satellite may not be available, for example, in tunnels, mines, buildings or other enclosed areas. The term "satellite", as used herein, is intended to include pseudoliths or equivalent of pseudolites, and the term "GPS signals", as used herein, is intended to include GPS signals from pseudolites. or equivalents of pseudolites.

[67] In the above analysis, the invention has been described with reference to the application on the United States Global Location Satellite (GPS) system. It should be clear, however, that these procedures are equally applicable to similar satellite location systems and, in particular, to the Russian GLONASS system and the proposed Galileo European System. The GLONASS system differs mainly from the GPS system in that the emissions from the different satellites are differentiated from each other by using slightly different carrier frequencies, instead of using different pseudo-random codes. In this situation, essentially all the circuits and algorithms described above are applicable. The term "GPS" used herein includes such alternative satellite tracking systems, including the Russian GLONASS system and the European Galileo System.

[68] Although the operations in the previous examples are illustrated in specific sequences, from this description, it will be appreciated that several different sequences of operation, and their variations, can be used without having to be limited to the examples illustrated above.

[69] The above examples are illustrated without presenting some of the details known in the art; As noted in the previous discussion, these details can be found in publications, such as US Patents 5,812,087; 5,841,396; 5,874,914; 5,945,944; 5,999,124; 6,061,018; 6,208,290 and 6,215,442.

[70] In the above specification, the invention has been described with reference to specific exemplary embodiments thereof. It will be apparent that various modifications can be made thereto without departing from the scope of the invention, as set forth in the following claims. Descriptive memory and drawings, therefore, should be considered in an illustrative sense, rather than in a restrictive sense.