Patent Application
20150189464
1. Field of the Invention
Embodiments of the present invention relate to wireless telecommunications technology.
2. Related Art
Wireless networks, for example wireless cellular networks, have interconnected wireless transmitters and receivers known as wireless base stations (WBSs) spread throughout a coverage area. A WBS may be, for example, a cell tower or a wireless access point such as a WiFi or Bluetooth receiver. The coverage area of a WBS is generally referred to as a cell. A mobile communication device (mobile device) connects to the rest of the network by establishing a communications connection with a selected WBS when it is located in the cell corresponding to the WBS. As the mobile device moves within the carrier's coverage area, it may transition from one cell to another by establishing communications with a WBS corresponding to each cell.
A location based service (LBS) leverages a user's physical location to provide an enhanced service and experience. A server system providing a LBS may obtain the mobile device's physical location with the use of explicit location information such as that provided by a global positioning system (GPS) device and carrier-provided information. The location information may then be used to customize the services provided to the mobile device. Maps of the mobile device's current surrounding area, traffic in the surrounding area, and nearby restaurant lists are some of the more common LBS services that are currently available.
Presently, a mobile positioning technique known as COO, or Cell of Origin, can be used to approximate a caller's cell location. Most commercially implemented COO systems rely on the fact that the mobile devices constantly measure the signal strength from the closest base stations and lock on to the strongest signal. The COO systems consider the location of the base station to be the location of the mobile device. Such an analysis does not deliver an accurate location. A more accurate position can be obtained when COO is used in conjunction with some other technology, such as the Global Positioning System (GPS) or Time of Arrival (TOA).
When accurate information such as GPS is unavailable for determining the current location of a mobile device, a LBS server requires a determination of the position through other means. Not all devices are equipped with a GPS capability. One way to determine the physical location of a mobile device is by identifying the one or more WBSs within whose cell areas the mobile device is located, and then determining the position of the mobile device relative to the fixed locations of those WBSs. Although network carriers have exact location information for all of their owned WBSs, that information is rarely made available to other service providers or users of mobile devices. Therefore, a LBS server must resort to other means for determining the location of a mobile device to which it provides services. Some information may be obtained from the mobile device itself, but such information is often incomplete. What is needed is a system and method for determining the location of a mobile device when only partial or incomplete information regarding the associated WBS cell is received.
Embodiments of the present invention relate to systems and methods for determining the geographical location of a user with limited and/or ambiguous information associated with the user's mobile device. In an embodiment, a method for determining the geographical location of an end user utilizing information associated with the user's mobile device involves a two step process. The first is a data collection phase in which all possible location information, WBS region identification information and non-location attributes are collected for a number of mobile devices. A geo-calibration algorithm is then executed which determines defined regions associated with like identification information and attributes. The second phase is a lookup phase in which the information accumulated in the collection phase is assessed to identify a region associated with a particular mobile device.
If the mobile device only returns a partial set of identification information for the WBS region, a conflict may occur where two WBS regions can be identified using the partial identification information. In this situation a geographical pre-classification system may analyze non-location attributes of the conflicting WBS regions to determine the proper geographic region associated with each WBS region.
In this way a mobile device's geographic location can be determined with a high degree of confidence using limited and ambiguous information available from the user's wireless communication device.
Further embodiments, features, and advantages of the invention, as well as the structure and operation of the various embodiments of the invention are described in detail below with reference to accompanying drawings.
While specific configurations, arrangements, and steps are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art(s) will recognize that other configurations, arrangements, and steps may be used without departing from the spirit and scope of the present invention. It will be apparent to a person skilled in the pertinent art(s) that this invention may also be employed in a variety of other applications.
It is noted that references in the specification to “one embodiment”, “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of one skilled in the art to incorporate such a feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
Embodiments of the present invention relate to the ability to identify the location of a person using a mobile communication device (mobile device). While some devices, such as mobile cellular phones, are equipped with global positioning system (GPS) capabilities, not all devices have such ability. In addition, devices that have built in GPS functionality do not necessarily generate an accurate geographic location. In examples described in this disclosure, information may be gathered by the mobile device which includes partial identification information related to the wireless base station region, as well as non-location based attribute data, both of which can be combined and analyzed to identify the regional location of the user.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those skilled in the art with access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the invention would be of significant utility.
In an example of a wireless communication system using a Global System for Mobile communication (GSM) cellular network, communication with a mobile device occurs through a wireless base station (WBS). The geographic range covered by the WBS is referred to herein as a cell or region. A cell may correspond to the coverage area of a plurality of wireless technologies including for example and without limitation, GSM, EDGE, IEEE 802.11, and Bluetooth. In some embodiments, a cell may correspond to any area or network that is connected to the carrier network through a WBS. For example, a user network covering an entire building, an adhoc wireless network, a personal area network, or other local area network, may be connected to the carrier network through a WBS. Each WBS region can be uniquely identified using the following four parameters: mobile network code (MNC), mobile country code (MCC), local area code (LAC), and cell identification (CID). The MNC defines the wireless carrier used by the WBS to provide a communication to the mobile device. The MCC defines the country in which the WBS region is located. As an example, an MCC of “505” with an MNC of “03” represents the communications operator Vodafone in Australia on the GSM 900/1800 and UMTS 2100 frequencies. The LAC provides the local area in which the WBS region exists. The CID is the identification number assigned to the WBS region within the local area. For a particular carrier in a particular country, the combination of the LAC and CID uniquely identify an active WBS region. If a complete identifier containing all four parameters (i.e., MNC, MCC, LAC, and CID) is received for a mobile device, then the active WBS region, and thus the location of the mobile device, can be identified. It is possible, however, that different carriers may use the same LAC/CID combination, and/or that WBS regions in different countries may be identified by the same LAC/CID combination. If only a partial identifier containing the LAC and CID is received without the corresponding MNC or MCC, there may be some ambiguity as to which WBS region is active since multiple cells may be identified by the same LAC/CID combination.
The ambiguity that arises when identical partial information is associated with multiple WBS regions is referred to as a “collision.”
The size of a region may be defined by taking the convex hull of locations determined to be within the region. A first indication that a collision exists occurs when a region R corresponding to a particular partial identifier is much greater than that expected or possible for the region. For example, if the region is expected to have a size consistent with the in-range area of a single WBS, but the region corresponding to the partial identifier spans multiple continents, a collision may be inferred. To detect such collisions, a threshold T may be defined, wherein T is the expected size of a region. If R is greater than T, a collision is inferred.
One difficulty with this type of collision detection is that the threshold T may vary by technology, user population density, carrier, terrain, or other factors. Nonetheless, some generalizations are possible to make approximate inference of collision.
A second indication that a collision exists occurs when a clustering algorithm is run on a region R, and two or more distinct geographic clusters are detected within region R. For example, within a “region 1,” there could be two non-overlapping, or somewhat overlapping, concentrations, e.g., locations, of mobile devices, where “cluster A” is located in the eastern section of region 1 and “cluster B” is located in the western section of region 1. As each region includes multiple locations of individual mobile devices, an analysis of those locations may indicate that the locations typically fall in one of two (or more) clusters. If multiple clusters are detected, a collision is inferred, since it is possible that each cluster corresponds to a different WBS region. False collision detection may occur if a single WBS region actually does include multiple clusters of devices, but such a false positive can be mitigated through further assessment of the data.
When a collision exists, the location of the mobile device from which the partial identification information was received cannot be accurately estimated. However, as will be described below, non-location attributes related to the particular mobile device may be combined with the partial identification information to estimate the location of the mobile device. Preclassification of WBS regions may be consulted in order to assist in determining the actual WBS region in use.
In step 204, a location indication is received for the mobile device. The location indication may be received from, for example, a GPS unit associated with the mobile device. For a mobile device without GPS capability, the location indication may be provided in other ways. For example, the portion of an electronic map being displayed by the mobile device may provide an indication of the mobile device location. Each location indication is indicative of a specific point or location within a larger WBS region.
In step 206, at least one non-location attribute is received for the mobile device.
One of skill in the art will recognize that steps 202, 204, and 206 may occur in any order, and any or all of steps 202, 204, and 206 may occur simultaneously, without departing from the spirit and scope of the present invention. Steps 202, 204, and 206 may be performed for a plurality of mobile devices to obtain information for a number of different locations.
In steps 208 and 210, the received attributes are used to preclassify partial identifiers into corresponding WBS regions.
In step 208, the locations associated with a given partial identifier (e.g., a LAC/CID combination) are sorted based on one or more non-location attributes. In an example, the non-location attribute is the radio type, such as GSM, CDMA, etc. If the set of all radio types is W, then the individual radio types within W are W1, W2, etc. That is, W={W1, W2, . . .}. If the set of locations associated with a given partial identifier is L, the subset L(W1) includes locations associated with the given partial identifier and the radio type W1. Iterative classifications may be made so that each non-location attribute received defines a subset of locations associated with a given partial identifier.
In the example of
In step 210, the locations in each subset defined by the partial identifier and non-location attribute combinations are analyzed to determine an encompassing WBS region for each subset. That is, a subset L(W1) is associated with a WBS region R. Continuing with the example from step 208, a subset L(GSM) is associated with WBS region 110 because it includes the location of mobile device 114. Similarly, a subset L(CDMA) is associated with WBS region 120 because it includes the location of mobile device 124. If multiple non-location attributes are available, a single WBS region R may be associated with multiple location subsets for different combinations of partial identifiers and non-location attributes. As a result of step 210, each region R is associated with one or more combinations of partial identifiers and non-location attributes.
Once the WBS regions are preclassified based on corresponding partial identifiers and non-location attribute combinations, a disambiguation process may be initiated in order to ascertain which region is the properly associated region for an unknown mobile device providing a particular partial identifier. This process utilizes one or more non-location attributes from the mobile device, referred to herein as disambiguating signals, in conjunction with a partial identifier to select the region.
In step 504, a partial identifier, such as an LAC/CID data pair, is received for a mobile device, as well as a non-location attribute that can be used as a disambiguating signal.
In step 506, a plurality of geographic regions that correspond to the partial identifier is determined. Since the partial identifier is incomplete, such as including just the LAC/CID pair data, multiple geographic regions may be identified as corresponding to the partial identifier. Each of the identified regions has been pre-classified based on at least one non-location attribute that was identified and collected by, for example, method 200 of
In step 508, a subset of regions corresponding to the received non-location attribute is determined from the plurality of regions obtained in step 506. The subset of regions is determined using the preclassification of regions by non-location attribute created by, for example, method 200 of
An iterative approach to disambiguation may be used if it is determined that a number of locations in a subset of locations corresponding to a non-location attribute are likely to be erroneous. As an example, a determination may be made that a specific type of disambiguation signal is incorrect and location data may be assigned to a generic location set for which no disambiguation signal has been found.
In step 510, a region in the subset of regions determined in step 508 is selected as the location of the mobile device. In an embodiment, an associated confidence score which indicates the certainty of the inference of the specific region may be utilized in selecting the region. For example, in an embodiment, step 510 may include the use of a filter and/or a filter-boost algorithm which compares one region in the subset with another region in the subset, wherein the initial region's confidence score can be increased based on how closely the initial region matches the other region in terms of geographic coverage.
A filter algorithm, according to an embodiment of the present invention, operates by obtaining an output region R, location L, and confidence C for each partial identifier, without referring to a disambiguating non-location attribute. The algorithm then obtains an output region R(j), location L(j), and confidence C(j) for each non-location attribute j. For each region R(j), a new confidence score S(j) is obtained by comparing the sets of <region R(j), confidence C(j)> against the region and confidence score without the disambiguating signal. The region R(j) having the highest confidence score S(j) may be selected as the location of the mobile device.
A filter-boost algorithm according to an embodiment of the present invention may be based on the idea that the confidence score S(j) for region R(j) nominally equals its initial confidence score, confidence C(j). However, when the score is compared with another region, region R(k), the score can be boosted depending upon how closely region R(j) matches region R(k) in terms such as geographical coverage and that region's initial confidence score, confidence C(k). Therefore, the final confidence score for region R(j) is determined from the function score S(j)=confidence C(j)+Sum {i=0, max} {Boost (j,i)} where for convenience the function Boost (j,0) refers to comparison with region R(0)=region R. An example boost function is Boost (j,k)=[area(intersection(Rj,Rk))/area(Rj)]*[1+C(k)−C(j)]. In this example, area(R) is the area of region R in square meters, and intersection(R, P) is the intersection of geographic regions R and P.
As an example, in a given pair of regions Rj and Rk, Rj receives a boost from Rk. Rk receives an equal boost from Rj if C(j)=C(k), less boost if C(j)<C(k), and greater boost otherwise. Thus, boosts are not necessarily symmetric. Even if the boost for a particular pair Rj and Rk are in fact symmetric, the final confidence scores S(j) and S(k) may not be equal. If there are two regions Rj and Rk with equal final scores, there are a number of options that can be executed to select the proper region as the location of the mobile device. Such options include, for example and without limitation, breaking ties arbitrarily, serving each region with equal probability for each request and collecting some user data to determine which one seems more suitable, or simply not serving any region.
Another example of the boost function is Boost(j,k)=[area (intersection(Rj,Rk))/area(Rj)]*[1+C(j)*sum{C(k)}]. Other boost functions can be defined that are similar in spirit and scope and that may be suited to a particular system, technology, application set, and other factors.
The Filter-Boost algorithm as described is potentially computationally intensive and various standard computer science techniques can be used to make it faster without departing from the spirit and scope of the present invention. It is also possible to automatically tune the operation of the Filter algorithm using machine learning techniques.
During a collection phase, such as that described with respect to method 200 of
In an embodiment, when application server system 310 receives a request for another mobile device 114 to, for example, display a map of the device's location, application server system 310 may provide a partial identifier and a non-location attribute received from mobile device 114 to geographic preclassification system 320.
In order to determine a location of mobile device 114 based on the partial identifier received from mobile device 114, geographic preclassification system 320 may use method 500 of
Once geographic preclassification system 320 returns the region associated with mobile device 114, application server system 310 may retrieve, for example, a map corresponding to the region from application database 312 and transmit the map to mobile device 114.
It is to be appreciated that the Detailed Description section, and not the
Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventor(s), and thus, are not intended to limit the present invention and the appended claims in any way.
Embodiments of the present invention have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.
The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present invention. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
This application claims the benefit of U.S. Provisional Application No. 60/990,238 filed Nov. 26, 2007; U.S. Provisional Patent Application No. 60/990,569, filed on Nov. 27, 2007; and U.S. Provisional Patent Application No. 61/196,167, filed on Oct. 15, 2008, which are incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 60990238 | Nov 2007 | US | |
| 60990569 | Nov 2007 | US | |
| 61196167 | Oct 2008 | US |
