Augmentation of call data information to determine a location of a wireless communication device

Embodiments disclosed herein provide systems and methods for augmenting call data information to determine a location of a wireless communication device. In a particular embodiment, a method provides receiving wireless signals transmitted from a plurality of base stations and determining signal strengths for at least some of the wireless signals. The method further provides identifying at least three geographically diverse ones of the base stations having signal strengths that satisfy a location-determination strength threshold. The method further provides transmitting base station identifiers and associated signal strengths for the geographically diverse base stations.

TECHNICAL BACKGROUND

Many methods exist for determining the location of a wireless communication device. One of those methods is performed predominantly by a wireless communication network. In particular, the wireless network may receive information from the wireless device that indicates with which wireless base station the wireless device is exchanging communications. The wireless network can then infer that the wireless device is located somewhere within the wireless coverage area of that base station.

The location determined using the information described above only provides the wireless network with a level of accuracy down to the nearest base station. Thus, it may be desirable for the wireless network to determine a more accurate location of the wireless device. Other methods exist in the wireless device, such as Global Positioning System (GPS) receivers, that are able to provide the wireless network with more accurate location information. However, these other methods typically must provide their determined location information to the wireless network in communications beyond the communications already exchanged with the wireless network when placing a call.

OVERVIEW

Embodiments disclosed herein provide systems and methods for augmenting call data information to determine a location of a wireless communication device. In a particular embodiment, a method provides receiving wireless signals transmitted from a plurality of base stations and determining signal strengths for at least some of the wireless signals. The method further provides identifying at least three geographically diverse ones of the base stations having signal strengths that satisfy a location-determination strength threshold. The method further provides transmitting base station identifiers and associated signal strengths for the geographically diverse base stations.

DETAILED DESCRIPTION

FIG. 1illustrates wireless communication system100. Wireless communication system100includes wireless communication device101, base stations102-105, and wireless communication network106. Wireless communication device101and base stations102-105communicate over wireless links111-114, respectively. Base stations102-105and wireless communication network106communicate over communication links115-118, respectively. The locations of elements101-106in FIG.1do not necessarily represent the relative locations of elements101-106in a geographic area.

In operation, wireless network106provides wireless communication services to wireless communication devices, including wireless device101, via wireless base stations, including base stations102-105. During the provision of the wireless communications services wireless network106, or some other system associated with wireless network106, wireless network106may determine and/or track locations of wireless devices. The location may be relevant to how the services are provided, how the services are billed, network statistical information, third party applications, or any other reason for knowing the location of a wireless device—including combinations thereof.

In some cases, a location of a wireless device may be identified to wireless network106based on a base station with which a wireless device is communicating. Wireless network106can then infer the location of the wireless device as being within a geographic area that is serviced by the identified base station. For example, a Reveal Location platform within wireless network106may receive Per Call Measurement Data (PCMD) from wireless device101that includes an active set for wireless device101. The active set identifies a base station currently serving wireless device101and the Reveal Location platform infers the location of wireless device101from the identified base station. While, in some situations, a single base station level of granularity for the location of a wireless device may be sufficient, other situations may find more accurate device locations useful.

FIG. 2illustrates an operation of wireless communication system100for augmenting call data information to determine a location of a wireless communication device. Wireless device101receives wireless signals transmitted from base stations102-105and determines signal strengths for at least some of the wireless signals (step200). The wireless signals may be pilot signals, control channels, traffic channels, or any other type of wireless signal that may be transmitted from a base station—including combinations thereof.

Wireless device101identifies at least three geographically diverse ones of base stations102-105having signal strengths that satisfy a location-determination strength threshold (step202). Wireless device101may determine the geographic diversity of a base station by first determining a location of the base station. In some embodiments, each of base stations102-105may include its geographic coordinates. In alternative embodiments, wireless device101may maintain a data structure of base station coordinates and associated base station identifiers that allows wireless device101to look up a base station's location using the base station's identifier. In some embodiments, each of base stations102-105may broadcast coordinates of the other base stations in addition to their own coordinates. This functionality may be accomplished by including neighboring base station coordinates in a neighbor list transferred to wireless device101. Other methods of determining a base station location may also be used.

Once the locations of base stations102-105are determined. Wireless device101processes the locations to determine the geographic diversity of base stations102-105. Base stations102-105may be considered geographically diverse if they are located more than a certain distance from another base station, located more than certain distances from two or more other base stations, located more than a certain distance and a certain angle from a line including two other base stations with one of the other base stations being a vertex, or any other way that a device may determine that two locations are geographically diverse. In some embodiments, wireless device101may factor in a relative geometric shape formed if lines where drawn between the base station locations to determine whether the shape would be beneficial to location determination. For example, three base stations located substantially on the same line would be less useful for location determination than three base stations forming a triangle around wireless device101.

The signal strengths of the wireless signals may be measured by wireless device101as part of the normal operation of wireless device101. In particular, wireless device101measures signal strengths of wireless signals from various base stations in order to determine with which base station wireless device101should exchange wireless communications. However, instead of discarding signal strengths that fall below a threshold for communication exchanges, wireless device101further compares the signal strengths to the location-determination strength threshold to determine whether the signal strengths are sufficiently high to aid in location determination. The signal strengths and, in some embodiments, pilot phases measured by wireless device101for base stations with high enough signal strengths may then be used to estimate how far wireless device101is from each base station.

After identifying the geographically diverse base stations, wireless device101transmits base station identifiers and associated signal strengths for the geographically diverse base stations (step204). The base station identifiers may comprise any type of identifier that uniquely identifies the base station to wireless network106. In some embodiments, each of the base station identifiers may identify a particular wireless sector from which the wireless signal for that base station was transmitted (e.g. a unique PN code for the wireless sector). For example, the base station identifiers may include identifiers for base stations102-104because base station105was determined to either not be geographically diverse from one or more of base stations102-104, the wireless signal from base station105may not have been above the location-determination strength threshold, or both.

In some embodiments, the base station identifiers are transferred along with an active set for wireless device101. Likewise, one or more of the base station identifiers may be included in the active set. An active set indicates a wireless sector that is currently providing wireless device101with wireless communication services along with other wireless sectors that are candidates to provide wireless communication services upon wireless device101performing a soft handoff to one of those other sectors. In some embodiments, the active set and the base station identifiers are transferred in a route update message (possibly as part of PCMD), which may be transmitted to wireless network106upon initiation of a call between wireless network106and wireless device101.

Wireless network106may use the base station identifiers to determine the location of wireless device101. In particular, a location determination system, such as a Reveal Location platform, in wireless network106, uses the information received from wireless device101to estimate the location of wireless device101. Wireless network106may use the base station identifiers to determine the locations of the base stations associated with the base station identifiers by referencing a database of base station identifiers and associated locations or by some other means. The signal strengths from each of the base stations may then be used to estimate how far wireless device101is from each base station since wireless signal strengths tend to decrease as distance increases from the transmitter of the signal. The location of wireless device101may then be estimated as being near a geographic point where the estimated distance from each base station converges.

Referring back toFIG. 1, wireless communication device101comprises Radio Frequency (RF) communication circuitry and an antenna. The RF communication circuitry typically includes an amplifier, filter, modulator, and signal processing circuitry. Wireless communication device101may also include a user interface, memory device, software, processing circuitry, or some other communication components. Wireless communication device101may be a telephone, computer, e-book, mobile Internet appliance, wireless network interface card, media player, game console, or some other wireless communication apparatus—including combinations thereof.

Wireless base stations102-105each comprise RF communication circuitry and an antenna. The RF communication circuitry typically includes an amplifier, filter, RF modulator, and signal processing circuitry. Wireless base stations102-105each may also comprise a router, server, memory device, software, processing circuitry, cabling, power supply, network communication interface, structural support, or some other communication apparatus.

Wireless communication network106comprises network elements that provide communications services to wireless device101through base stations102-105. Communication network103may comprise switches, wireless access nodes, Internet routers, network gateways, application servers, computer systems, communication links, or some other type of communication equipment—including combinations thereof.

Wireless links111-114use the air or space as the transport media. Wireless link111-114may use various protocols, such as Code Division Multiple Access (CDMA), Evolution Data Only (EVDO), Worldwide Interoperability for Microwave Access (WIMAX), Global System for Mobile Communication (GSM), Long Term Evolution (LTE), Wireless Fidelity (WIFI), High Speed Packet Access (HSPA), or some other wireless communication format. Communication links112-118use metal, glass, air, space, or some other material as the transport media. Communication links112-118could use various communication protocols, such as Time Division Multiplex (TDM), Internet Protocol (IP), Ethernet, communication signaling, CDMA, EVDO, WIMAX, GSM, LTE, WIFI, HSPA, or some other communication format—including combinations thereof. Communication links112-118could be a direct link or may include intermediate networks, systems, or devices.

FIG. 3illustrates wireless communication system300. Wireless communication system300includes wireless communication device301and base stations302-305. Base stations302-305exchange wireless communications with wireless communication devices, including wireless device301, within three wireless sectors S21-S23, S31-S33, S4-S43, and S51-S53, respectively. The locations of elements301-305inFIG. 3reflect exemplary geographic locations of elements301-305relative to one another. Though not shown, base stations302-305are connected to a wireless network like wireless network106fromFIG. 1. The wireless network includes a location determination system that determines a location of wireless device301based on pilot signals identified by wireless device301, as described below.

FIG. 4illustrates an operation of wireless communication system300for augmenting call data information to determine a location of a wireless communication device. Wireless device301receives pilot signals from wireless sectors of base stations302-305(step400). A neighbor list received by wireless device301from the wireless network of base stations302-305may indicate frequencies for the pilot signals to wireless device101. Wireless device301may be able to receive all of the pilot signals from all of the sectors shown inFIG. 3or may only be able to receive a subset of the pilot signals due to signal propagation limitations for some wireless sectors relative to the location of wireless device301.

Wireless device301determines signal strengths of at least some of the received pilot signals (step402). The signal strengths may be determined as part of the normal operation of wireless device301when determining which wireless sectors should be included in the active set for wireless device301or may be determined as part of a separate operation. Wireless device301further determines a location of each base station transmitting the pilot signals for which signal strengths were determined (step404). In this embodiment, the pilot signals include geographic coordinates for their respective base stations. Wireless device301thereby determines the base station locations from the coordinates in the received pilot signals.

Once the locations and signal strengths have been determined, wireless device301determines which sectors to include in a non-active set for location determination based on the signal strengths and base station locations (step406). In particular, wireless device301determines whether the signal strength of the received pilot signals is greater than a threshold for location determination yet also below a threshold for placing the pilot signal in an active set for wireless device301. If the signal strength is above the active set threshold, then the corresponding pilot signal is already placed in the active set and would not warrant being included in the non-active set. Each pilot signal for inclusion in the non-active set should be higher than the location determination threshold so that the signal strength is high enough to estimate distance from the transmitting base station.

In addition to the signal strengths meeting the thresholds described above, the locations of the base stations transmitting the pilot signals satisfying the above thresholds are processed to determine which of the signals are transferred by geographically diverse base stations. The locations of one or more base stations whose pilot signals are included in the active set are further considered when determining geographical diversity of base stations to be included in the non-active set. In other words, the geographic diversity of base stations is determined across all base stations for transmittal to the wireless network, regardless of the set in which the base stations are included.

Once the active and non-active sets have been determined, wireless device301transfers the two sets in a route update message to the location determination system of the wireless network (step408).FIG. 5illustrates an exemplary route update message500that may be transferred in the present embodiment. Route update message500may be transferred as part of PCMD. Route update message500includes both an active set and a non-active set determined during the steps described above. In particular, the active set identifies the wireless sector currently servicing wireless device301in the form of the Pseudo Noise (PN) code broadcast in the pilot signal for sector S41of base station304. The active set further identifies the pilot phase and PN code of wireless sector S43, which is a likely sector for handoff of wireless device301from sector S41. Additionally, the non-active set included in route update message500lists PN codes and pilot phases for wireless sectors S22and S33of base stations302and303, respectively.

In this example, wireless device301determined to include sectors S22and S33in the non-active set based on the geographic diversity of base stations302and303when compared to base station304, which is already included in the active set. Specifically, base stations302and303may be included in the non-active set based on the fact that, along with base station304, base stations302-304form a geographically diverse triangle around wireless device301. In some embodiments, additional sectors from base stations302and303may be included in the non-active set if their respective pilot signal strengths meet the thresholds discussed above. However, inclusion of these pilot signals in the non-active set may not be necessary since they are transmitted from a base station already included in the non-active set. In other words, the non-active set may only include a pilot signal having the greatest strength of all threshold qualified pilot signals received from any given geographically diverse base station.

While wireless device301may have received one or more pilot signals from base station305, no pilot signals from base station305are included in the non-active set. Those pilot signals may not be included in the non-active set because their signal strengths did not exceed the location determination threshold, the location diversity of base station305relative to base stations302-304was not sufficient, or a combination of both factors. For example, even if the signal strength of the pilot signal for wireless sector S53where great enough for inclusion in the non-active set, base station305is substantially located on a line along with base stations302and304. Therefore, the location of base station305is effectively redundant to the location of base station304for the purposes of determining a location of wireless device301and is not included in the non-active set. If, however, base station305were located in the area represented by the dashed representation of base station305, then base station305may be considered geographically diverse enough to provide relevant location information about wireless device301and sector S53may accordingly be included in the non-active set.

Referring back toFIG. 4, in response to receiving the route update message from wireless device301, the location determination system of the wireless network determines a location of wireless device301based on the information included in the active and non-active sets therein (step410). Specifically, the location determination system determines the locations of base stations302-303indicated by the pilot signals of the active and non-active sets of route update message500. Additionally, the location determination system uses the signal strengths and pilot phase measurements indicated for each of the pilot signals in route update message500to estimate a distance from each of base stations302-303. The distance estimates may be determined from a data structure listing the typical distance from a base station a received power level would indicate for each possible transmit power level. For example, the location determination system may determine that the −2 db signal strength for the pilot signal of wireless sector S41indicates that wireless device301is about one-half mile from base station304. The location determination system is then able to determine a location for wireless device301as being the location where the estimated distances from each of base stations302-304converge. In some embodiments, the estimated distances may not all converge so the location determination system may use a best-fit approximation for the location of wireless device301based on the distances.

Advantageously, the location determination system can determine a location of wireless device301based on additional information (i.e. the non-active set) included in a route update message that would otherwise be provided to the wireless network anyway.

In some embodiments, a route update message is transferred each time wireless device301initiates a voice or data call over the wireless network. Thus, the location of wireless device301may be determined each time wireless device301initiates a call. Steps400-406described inFIG. 4to generate the route update message may also not occur until the call is initiated or may occur continually/periodically so that the route update message is ready for transfer upon initiation of the call.

FIG. 6illustrates wireless communication device600. Wireless communication device600is an example of wireless communication device101, although device101could use alternative configurations. Wireless communication device600comprises wireless communication interface601, user interface602, and processing system603. Processing system603is linked to wireless communication interface601and user interface602. Processing system603includes processing circuitry605and memory device606that stores operating software607. Wireless communication device600may include other well-known components such as a battery and enclosure that are not shown for clarity. Wireless communication device600may be a telephone, computer, e-book, mobile Internet appliance, media player, game console, wireless network interface card, or some other wireless communication apparatus—including combinations thereof.

Wireless communication interface601comprises RF communication circuitry and an antenna. The RF communication circuitry typically includes an amplifier, filter, RF modulator, and signal processing circuitry. Wireless communication interface601may also include a memory device, software, processing circuitry, or some other communication device. Wireless communication interface601may use various protocols, such as CDMA, EVDO, WIMAX, GSM, LTE, WIFI, HSPA, or some other wireless communication format.

User interface602comprises components that interact with a user to receive user inputs and to present media and/or information. User interface602may include a speaker, microphone, buttons, lights, display screen, touch screen, touch pad, scroll wheel, communication port, or some other user input/output apparatus—including combinations thereof. User interface602may omitted in some examples.

Processing circuitry605comprises microprocessor and other circuitry that retrieves and executes operating software607from memory device606. Memory device606comprises a non-transitory storage medium, such as a disk drive, flash drive, data storage circuitry, or some other memory apparatus. Processing circuitry605is typically mounted on a circuit board that may also hold memory device606and portions of communication interface601and user interface602. Operating software607comprises computer programs, firmware, or some other form of machine-readable processing instructions. Operating software607includes signal strength module608and location diversity module609. Operating software607may further include an operating system, utilities, drivers, network interfaces, applications, or some other type of software. When executed by processing circuitry605, operating software607directs processing system603to operate wireless communication device600as described herein.

In particular, signal strength module608directs processing system603to receive, via communication interface601, wireless signals transmitted from a plurality of base stations and determine signal strengths for at least some of the wireless signals. Location diversity module609directs processing system603to identify at least three geographically diverse ones of the base stations having signal strengths that satisfy a location-determination strength threshold and transmit base station identifiers and associated signal strengths for the geographically diverse base stations via communication interface601.