Locating a wireless device based on information about base stations belonging to a plurality of networks

ES 2 347 263 T3

DESCRIPTION

Locating a wireless device based on information about base stations belonging to a plurality of networks.

Background

The present disclosure relates generally to the automatic determination of locations and, more specifically, but not by way of limitation, to the determination of a location of a wireless device.

There is a growing desire to know the geographical position of various mobile devices. For example, cell phone operators are trying to meet emergency equipment location requirements. Once the position is known, emergency personnel can be dispatched to help establish the emergency. Knowing your geographic location serves many other purposes such as geography-related advertising, child supervision, automatic probation supervision, reverse 911, vehicle fleet tracking, and more.

Conventional location techniques present difficulty in accurately establishing location in certain situations. Satellite location systems suffer from inaccuracies when a clear view of the sky is not available. Ground systems require communication with various base stations that serve as known references during trilateration, but in some scenarios, since these systems were designed primarily for communication purposes, there are not enough geographically dispersed base stations within the communication range of the mobile device. Even though communication to multiple base stations is possible, multipath induced inaccuracies can impair the ability to establish a precise location.

Conventional location techniques cause a cordless telephone to interact with base stations associated with the service to which the cordless telephone is subscribed. A base station almanac tells the cordless phone where the base stations are located. In most cases, at least a couple of base stations are visible to the cordless phone.

Cell phones often have a limited memory to store additional information. Base stations are constantly being added, removed, or relocated in a cell phone network. Base station almanacs are occasionally sent to cell phones to help determine location. Communicating and storing a large almanac is impractical on some cell phones.

US Patent No. 6,236,365 describes determining the location of a mobile station using a plurality of commercial wireless infrastructures.

Summary

The present invention relates to a system and a method for locating a position of a wireless device as defined in the appended claims.

A method and system are disclosed that allow the location of a wireless device to be established. Setting the location in one embodiment is based on access to at least one cooperating base station and at least one non-cooperating base station. The cooperating base station provides an almanac of base stations that are likely to be close to the wireless device. Both the cooperating and non-cooperating base stations in range can be used to determine the location of the wireless device. The uncooperative base station is generally not available to the wireless device, but can be used to determine the distance to the wireless device. An attempt by the wireless device to carry data or voice in the uncooperative base station may or may not be thwarted by the uncooperative base station.

In one embodiment, the base station population is reduced to produce a custom made base station almanac. The custom almanac includes information to uniquely identify each base station, and can include location information for the base stations.

In another embodiment, any number of different types of base station can be used. The base station can be a cell phone base station, a wireless local area network, a wireless wide area network, a satellite, a terrestrial location beacon, any other device that can somehow wirelessly communicate with the wireless device in a way that allows unique device identification and distance measurement.

In a variety of other embodiments, the general location of the wireless device is determined in different ways. Various embodiments could use the integral location function for the phone, the current cooperating base station and a putative cell fingerprint, multiple base stations to find an overlapping cell fingerprint, multiple cooperating base stations to trilaterate the position, base stations and satellites to trilaterate position, and / or one or more cooperating base stations that can determine range and angle. Different wireless devices have different capabilities, as do base stations, so various approaches can be used.

Brief description of the drawings

The characteristics, objectives and advantages of the embodiments of the disclosure will become more apparent from the detailed description set forth below taken in conjunction with the drawings, in which the same elements bear the same reference numerals. Furthermore, various components of the same type can be distinguished by adding to the reference symbol a dash and a second symbol that distinguishes the similar components from each other. If only the first reference symbol is used in the specification, the description is applicable to any one of the similar components having the same first reference symbol, regardless of the second reference symbol.

Figures 1A, 1B and 1C are block diagrams of embodiments of a location determination system;

Figures 2A and 2B are diagrams of embodiments of a single cell location system;

Figures 3A and 3B are diagrams of embodiments of a cell sector location system;

Figure 4 is a diagram of an embodiment of an overlapping cell location system;

Figure 5 is a diagram of an embodiment of a cellular trilateration system;

Figure 6 is a diagram of an embodiment of a hybrid trilateration system;

Figure 7 is a diagram of an embodiment of an angular range determination system;

Figure 8 is a flow chart of one embodiment of a process for locating a location of a wireless device having native locating functions;

Figure 9 is a flow chart of another embodiment of a process for locating a location of a wireless device having limited locating functions;

Figure 10 is a diagram of an embodiment of a system that collects location information from non-cooperating base stations;

Figure 11 is a flow chart of one embodiment of a process for collecting location information from base stations; and Figure 12 is a diagram of another system embodiment that collects location information from non-cooperating base stations.

Detailed description

Referring initially to FIG. 1A, a block diagram of one embodiment of a location determination system 100-1 is shown. The location determination system 100 allows wireless devices 120 to find their geographic location or be located by remote entities using satellites 152 (e.g., GLONASS, GPS, Galileo, EGNOS, Globalstar, IRIDIUM) and / or base stations 112, 124 ( for example, cell phone base station, wireless local area network, wireless wide area network, satellite phone, satellite Internet, or any other device that can be uniquely recognized and communicated with the wireless device 120). Cooperating base stations 112 are coupled to an almanac processor 122 via a wide area network (WAN) 110 in this embodiment, although other embodiments could use a local area network (LAN). Almanac processor 122 accesses a base station database 144 to tailor or customize an almanac based on the estimated location of wireless device 120.

A wireless device 120 can communicate with any number of devices to provide location information. In this embodiment, wireless device 120 is a cellular phone that can have any number or combination of communication modes (e.g., GSM, CDMA, TDMA, WCDMA, OFDM, GPRS, EV-DO, WiFi, Bluetooth, WiMAX, 802 .xx, ​​UWB, satellite, etc.) to transfer voice and / or data with cellular, satellite, wireless data and / or mesh networks through their base stations 112, 124. The wireless device 120 in other embodiments may be a tracking device, a child or parole monitor, a navigation device, a wireless pager, a wireless computer, a PDA, an item tag, etc. .

The communication modes supported by each wireless device 120 are stored in a device capabilities database 140 that includes information to help determine an uncertainty factor for each location or distance measurement made by a particular wireless device 120 that operates. in any number of communication modes.

This embodiment shows cooperating base stations 112, uncooperative base stations 124, and a satellite locator beacon 152, which may each have different modes of communication. For example, cellular base stations 112, 124 could support TDMA and GSM, one satellite base station could support only CDMA, or another satellite base station could support only TDMA.

Base stations 112, 124 are defined herein as allowing a certain type of data and / or voice transport. Base stations 112, 124 are often affiliated with some entity (for example, a Wi-Fi or cellular service provider) so that only subscribers or subscribers to another system with a roaming agreement can communicate with station 112, 124 base to pass data and / or voice traffic. Base stations 112, 124 may connect to a WAN or LAN to obtain a custom made almanac, but only cooperating base stations 112 provide a custom made almanac. The various base stations 112, 124 can have any number or combination of communication modes (e.g. GSM, CDMA, TDMA, WCDMA, OFDM, GPRS, EV-DO, WiFi, Bluetooth, WiMAX, 802.xx, UWB, satellite , etc.) to transfer voice and / or data with cellular, satellite, wireless data and / or mesh networks.

There are cooperating and non-cooperating base stations 112, 124. A cooperating base station 112 is one that allows data and / or voice communication with the wireless device 120. In one example, voice communication can be supported using Voice over IP (VoIP). The uncooperative base stations 124 may not allow data and / or voice traffic, but provide useful information for determining a location of the wireless device. Uncooperative base stations 124 provide a certain type of identifier and can often be used to determine range, which is a process in which the distance between base station 124 and wireless device 120 is determined. The identifier in the case of a WiFi base station 124, for example, includes a station identifier and a MAC address. Additionally, some non-cooperative base stations 124 allow range measurements, received signal strength indications, and beacon signaling capabilities, all of which can be used to determine range.

Base station database 144 stores identifier information that can be used to uniquely identify each base station in that class of base stations. For example, each WiFi base station can include a MAC address as identifier information. According to another example, a CDMA base station identifier can include SID, NID, and Base ID or SID, MSC ID, and Base ID. The characteristics of the base station 112, 124 can be used to uniquely identify the base station 112, 124. For example, if two base stations had the same station identifier, but only one supported a particular communication standard, the two could be uniquely identified. Typically, a wireless device 120 would support a subset of the various modes of communication.

ES 2 347 263 T3 communication. Location information that is determined for each base station 112, 124 by conducting area surveys with the wireless devices is also stored in the base station database 144.

In one embodiment, wireless devices 120 may be used to determine the location of each base station 112,124, then the location is returned to the almanac processor 112. Location information from various wireless devices 120 for each base station 112, 124 is added by almanac processor 112 to update the base station database. As more location data points are collected, they are weighted according to the accuracy of the location information provided by the wireless device 120 and used to establish the location of the base station with increasing accuracy. The accuracy of each wireless device 120 may be stored in the device capabilities database 140, which could have different accuracies for the various ways that a wireless device 120 may collect the information. Any uncertainties the wireless device 120 may have in knowing its location can also be reflected in the precision weighting for the base station database 144.

Wireless device 120 can use various types of location beacons to help determine location. This embodiment employs a satellite locating beacon 152, although terrestrial and pseudo-satellite beacon systems, such as LORAN, may also be used. The more location references, generally, the better the location of the wireless device 120 can be determined.

This embodiment shows the almanac processor 122 separate from the cooperating base stations 112, but each cooperating base station 112 or a class of cooperating base stations 112 may have an almanac processor 112 and / or databases 140, 144 in other embodiments. Some embodiments may integrate the almanac processor 122 into the wireless device 120. The base station and / or the device capabilities databases 144, 140 may also be on the wireless device 120 and be periodically updated.

Referring now to FIG. 1B, another embodiment of the location determining system 100-2 is shown. In some embodiments, the base station database 144 is centrally located, but the base station database 144 is distributed regionally or in relevant parts for each cooperating base station 112 or a class of cooperating base stations 112 as a local almanac 158 in the present embodiment. For example, a first base station 112-1 may store a portion of the base station database 114 for its footprint and all adjacent base station footprints in a first local almanac 158-1. According to another example, the first local almanac 1581 may contain the base station database for all or a selected set of CDMA base stations. According to yet another example, the first almanac 158-1 may not be geographically organized but contains the base stations that are part of a particular service provider network. When the centrally located base station database 144 is updated, these changes are propagated to the various local almanacs 158 that could use the new information.

This embodiment does not use a satellite locator beacon 152 or other type of locator beacon, but instead has one or more communication satellite base stations 154 for use in voice and / or data communication. This embodiment of the communication satellite base station 154 may have, but does not have, a local almanac 158 and / or databases 140, 144. Communication satellite base station 154 relies on almanac processor 122 to produce custom made almanacs. A satellite ground station 160 communicates with almanac processor 122 via WAN 110.

Referring now to FIG. 1C, yet another embodiment of the location determining system 100-3 is shown. In this embodiment, a cooperating base station 112 is coupled to a local area network (LAN) that is coupled to an almanac processor 122 and base station databases 140, 144 of device capabilities and capabilities. The information in the base station databases 140, 144 and device capabilities can be periodically updated or reconciled with remote master versions of these databases using a WAN or the like. The satellite base station 154 in this embodiment also includes a processor 122 for almanacs and bases 140, 144 for base station data and device capabilities, although that level of detail is not shown in the figure.

Referring to Figures 2A and 2B, diagrams of embodiments of a single cell location system 200 are shown. A cooperating base station 112 has a cell footprint 204 in which it can communicate with the wireless device 120. Figure 2A shows the uncooperative wireless base station 124 within that cell footprint 204.

Occasionally, wireless device 120 is nearly out of cell footprint 204 to communicate with cooperating base station 112, but may communicate with non-cooperating base stations 124 outside of this cell footprint as shown in FIG. 2B. An intermediate cell zone 208 will include non-cooperating base stations 124 outside of range of cooperating base station 112, but possibly within range of a wireless device 120 within range of cooperating base station 112. An uncooperative base station footprint 212 is shown for a base station 124 outside of the cell footprint, but within the communication range of the wireless device 120. The fact of including this base station 124 in the intermediate cell area 208 makes this scenario possible.

In this embodiment, wireless device 120 is within communication range of a single cooperating base station 112. In the cell footprint 204 of the cooperating base station 112, there are eleven non-cooperating base stations 124. Intermediate cell area 208 has two more non-cooperating base stations 124. When the almanac processor 122 receives a request for a custom made almanac, information is included for the thirteen possible non-cooperating base stations.

In one embodiment, the cooperating base station 112 may determine a range to the device.

Wireless ES 2 347 263 T3 vo 120 and almanac processor 122 may choose from the list of thirteen those that could be located within an annular ring around cooperating base station 112. The ring will be as thick as the range of the wireless device 120 when talking to the various non-cooperating base stations 124 in a particular mode plus a certain error factor as a result of determining the range to the cooperating base station 112. For example, the wireless device 120 may have a range from the cooperating base station 112 of fifty measurement units with an error factor of ten percent. In one communication mode, the range from the wireless device 120 is fifteen units. In this example, the annular ring will start with a radius of thirty and extend to seventy units of measure. Any base station 112, 124 that understands that mode of communication and that falls within that ring fingerprint will be included in the custom almanac. Of course, if the annular ring were to extend beyond the intermediate cell zone 208, the radius of the ring would be appropriately restricted.

Since the wireless device 120 may have different modes of communication with the various types of base stations, the thickness may be different for each type of communication mode with base stations. In addition, the wireless device 120 may receive almanac information about other cooperating base stations 112 that the wireless device 120 was unaware of.

In another embodiment, the almanac processor 122 could make a selection from the number of base stations 112,124 included in the custom made almanac. In some cases, the density of base stations 112, 124 is so great that including additional base stations 112, 124 that are in close proximity will be of little help in establishing the location of the wireless device 120.

In some embodiments, the almanac processor 122 could exclude base stations 112, 124 that have no way of being uniquely identified. For example, if two base stations had the same station identifier and did not provide other codes for unique identification, both could be excluded from the custom-built almanac. Many times, other identifiers in the communication protocol can be combined with the identifiers to create a unique identifier that distinguishes the base stations 112, 124. In some cases, two or more base stations 112, 124 that cannot be uniquely identified are so geographically separated that a unique identifier can be formulated knowing the geographic location of interest so that they can still be useful. Only one will be included in a tailor-made almanac.

Referring now to Figures 3A and 3B, diagrams of embodiments of a cell sector location system 300 are shown. This embodiment has six cell sectors 304 for a cooperating base station 112, although other embodiments may have any number of cell sectors. The wireless devices 120 in the cell footprint 204 are divided among the cell sectors 304 so that the base station 112 knows which cell sector (s) 304 is communicating with a particular wireless device 120. The cell sector (s) that the wireless device 120 might have are forwarded to the almanac processor 122. Any base station 112, 124 within cell sector (s) 304 is forwarded to cooperating base station 112 for retransmission to wireless device 120.

In the embodiment of FIG. 3A, a single cell sector 304 can communicate with wireless device 120. Almanac processor 122 will include base stations 112,124 in that sector 304 along with those in an intermediate sector zone 308. The embodiment of FIG. 3B shows the wireless device 120 near the edge between two cell sectors 304 so that both can receive communication. Almanac processor 122 may provide base stations 112, 124 in those two cell sectors 304 and an intermediate sector (s) zone 308 around them to any wireless device 120 near or near that area.

Referring to FIG. 4, a diagram of one embodiment of an overlapping cell locating system 400 is shown. In this embodiment, two cooperating base stations 112 may communicate with the wireless device 120 such that the overlap in cell footprints 204 is assumed to be the location of the wireless device 120. The almanac processor 122 will query the base station databases 140, 144 and device capabilities to determine how to tailor an almanac for this overlapping region 404. A portion of the intermediate cell area 208 that overlaps with the intermediate cell area 208 of the other cell footprint 204 and the intermediate cell area 208 (and vice versa) will also be analyzed for the base stations 112, 124 to be included. in a custom made almanac.

Referring now to FIG. 5, a diagram of one embodiment of a cellular trilateration system 500 is shown. In this embodiment, the wireless device 120 can communicate with three or more cooperating base stations 112-1, 112-2, 112-3 that are geographically separated. A general location of the wireless device 120 is determined by analyzing range information collected by or from several cooperating base stations 112. Time of arrival (TOA) readings from a cooperating base station 112 narrow down the general location to a ring around that base station 112. Two cooperating base stations 112 generating Time Difference of Arrival (TDOA) range readings reduce the location to hyperbole. Three or more can set the general location even more. In this embodiment, the time of arrival and / or time difference of arrival measurements are used in the trilateration process.

No matter how small the area turns out to be, an intermediate zone around that area is determined to compensate for the error in the determination and the range of the wireless device 120 is directed to the base stations 112, 124. Almanac processor 122 collects information for base stations 112, 124 that are likely to be within communication range for each communication mode supported by wireless device 120.

Referring to FIG. 6, a diagram of one embodiment of a hybrid trilateration system 600 is shown. This embodiment shows trilateration with different types of communication modes.

ES 2 347 263 T3

Wireless device 120 receives range information from a satellite locator beacon 152 and communicates with two cooperating base stations 112-1, 1122. Among the three 152, 112-1, 112-2, the general location can be trilateral and forwarded to one of the cooperating base stations 112 in exchange for a custom made almanac.

Referring now to FIG. 7, a diagram of one embodiment of an angular range determination system 700 is shown. Cooperating base stations 112 in this embodiment can estimate the angle of arrival (AoA) and distance to the wireless device. This capability allows a general location to be determined with a single cooperating base station 112. When the cooperating base station 112 can only determine the AoA and not the range, two cooperating base stations 112-1, 112-2 can determine a general location.

The above embodiments do not rely on uncooperative base stations 124 to find an initial location estimate, but rather request a custom almanac from cooperating base stations 112 for fine-tuned location estimates. Some embodiments may report on observed base stations 112, 124 and location beacons and any range estimates relative to these as part of a location request. The almanac processor 112 can take this information and determine a location using the base station databases 140, 144 and the device capabilities and mode of operation. In this embodiment, the initial collection of location information is done without benefiting from a custom made almanac. When the almanac processor 122 determines that a more precise location is required, a tailored almanac may be produced indicating additional base stations 112, 124 likely to be within range of the wireless device 120.

Referring to FIG. 8, a flow chart of one embodiment of a process for locating a location of a wireless device 120 having native location functions 800 is shown. Wireless device 120 may perform trilateration with cooperating base stations 112 or satellite or ground location beacons to determine a general location in step 804. At step 808, wireless device 120 reports the location estimate and requests a custom made almanac. Some wireless devices may store a base almanac of base stations 112, 124 which is updated as new custom made almanacs are received.

In this embodiment, the location estimate may be further fine-tuned outside of the wireless device in step 812. For example, the cooperating base station 112 may have some location information based on arrival time or arrival time difference. The general location is forwarded to the almanac processor 112. At step 816, the almanac processor 112 builds an almanac finding all base stations 112, 124 that could be close enough to be used in determining a location for the wireless device 120. This takes into account all of the wireless device 120 communication modes supported by the various base stations 112, 124, the likely range in those modes, and the likely location of the wireless device 120. This custom made almanac is sent over the WAN 110 to the cooperating base station 112 and relayed to the wireless device in step 820.

In step 824, the wireless device 120 collects additional location information. This location information uses the custom made almanac and may involve non-cooperating base stations 124 as well as cooperating base stations 112. In this embodiment, the wireless device 120 analyzes the location information to fine-tune the location estimate in step 828. The location estimate is reported to a cooperating base station in step 832. During the process of determining a location, the wireless device 120 may have location information for the base stations 112, 124 in the custom almanac or those not yet in the almanac. In step 836, this location information along with almanac-related information, such as the identifications of observed base stations, is reported to a cooperating base station 112 and forwarded to almanac processor 122 to update database 144. of base stations.

Referring now to FIG. 9, a flow chart of another embodiment of a process 900 for locating a location of a wireless device 120 having limited locating capabilities is shown. Some wireless devices have a limited ability to independently determine their location. This embodiment relies on other parts of the location determination system 100 to analyze the location information. At step 908, wireless device 120 requests a custom made almanac. The location is estimated by the various cooperating base stations 112 in step 912.

This location estimate is passed to the almanac processor 122 to tailor the almanac information at step 816. At step 820, the tailor-made almanac is sent to the wireless device 120. Step 824 collects additional location information using the custom made almanac to find uncooperative base stations 124. In step 916, the collected location information is forwarded to the cooperating base station 112. Step 928 refines the location estimate using the location information. Tuning can be performed at cooperating base station 112, almanac processor 122, or at any other location in communication with cooperating base station 112. Any additional information collected by the wireless device 120 is forwarded to the almanac processor 122 to refine the base station database 144.

Referring to FIG. 10, a diagram of an embodiment of a system 1000 that collects location information from uncooperative base stations 124 is shown. Upon receipt of the custom almanac by the wireless device 120, it attempts to locate the base stations listed in the almanac. In the embodiment of Figure 10 a wireless device 120 is shown

ES 2 347 263 T3 dual mode supporting two communication modes. One communication mode has a first fingerprint 1012-1 and the second has a larger fingerprint 1012-2. The custom made almanac will have all stations 112,124 base on the first fingerprint 1012-1 using the first communication mode and all stations 112, 124 base on the second fingerprint 1012-2 using the second communication mode.

In some embodiments, the almanac processor may perform a motion estimate for the wireless device 120 such that the footprints 1012 are adjusted for the likely position of the wireless device 120 when the custom made almanac is used. Other embodiments may simply expand the footprint based on the likely speed or the maximum speed of the wireless device 120 if it is moving in either direction. In still other embodiments, a history of handovers between various base stations can be used to tailor the almanac information.

Now referring to FIG. 11, a flow chart of one embodiment of a process 1100 for collecting location information from base stations 112, 124 is shown. The process 1100 begins at step 1104 where the wireless device 120 checks the base stations 112, 124 against the custom made almanac. This can be done by randomly choosing base stations in the almanac 112, 124. In some embodiments, the base stations 112, 124 may be pre-scrambled so that the wireless device 120 can take them in order.

In another embodiment, the almanac processor 122 may choose another scheme to organize the base stations 112, 124 to quickly find one. For example, they can be organized by communication mode and footprint size 1012. The almanac footprint is covered faster using communication modes with a longer range.

Once the base station 112, 124 is found in the almanac in step 1108, it is possible to exclude some of the base stations 112, 124 in the almanac. After traversing the various base stations 112,124 to find those within range of the wireless device 120, the distance to each of them is estimated in step 1112.

The uncooperative base stations 124 still provide some information even though data communication is not possible. They will identify themselves, indicating that the wireless device 120 is close enough to communicate. Some uncooperative base stations 124 will indicate the signal strength of a received signal. Other non-cooperating base stations 124 will acknowledge receipt of a message and that propagation time can be correlated with a distance traveled. The signal strength of a signal from the uncooperative base station 124 can serve to derive the distance when the initial or expected signal strength can be determined.

In some embodiments, the wireless device 120 collects information about base stations 112, 124 not included in the almanac in step 1116. Often, the base stations 112, 124 themselves identify themselves. If resources are available, at step 1120 a scoping may be made to unlisted base stations 112, 124 for later notification back to the almanac processor. In other embodiments, the base station footprint or overlaps of more than one footprint can be analyzed to determine the general location of the wireless device 120.

Referring to FIG. 12, there is shown a diagram of another embodiment of a system 1200 that collects location information from uncooperative base stations 124. The uncooperative base stations 124 depicted are those identified in a custom made almanac as likely to be within communication range. In this embodiment, three non-cooperating base stations 124-1, 124-4, 1245 operate in a first communication mode with first communication fingerprints 1212-1, 1212-4, 1212-5; two non-cooperating base stations 124-2, 1246 operate in a second communication mode with second communication fingerprints 1212-2, 1212-6; and a non-cooperative base station 124-3 operates in a third communication mode with a third communication fingerprint 1212-3. The current position of the wireless device 120 only allows communication with the three non-cooperating base stations 124-2, 124-3, 124-4. Even without range measurements, this can restrict the location of the wireless device 120, but with range measurements, a very precise location can be determined.

The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the disclosure. Various modifications of these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the invention as defined in the appended claims.