System and method for improving location estimates of co-located sectored cell sites for location services
Improved location estimates for transceivers is described. The location estimate of transceivers can be improved for sector transceivers that are co-located at a sectored cell site. The location estimate for each individual co-located sector transceiver can be updated as a centroid of all of the co-located sector transceivers. The location information of the transceivers can be used to provide network location estimation to mobile devices which do not have accurate positioning estimates.
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This application is a continuation of U.S. patent application Ser. No. 13/628,571 which issued on Sep. 30, 2014 as U.S. Pat. No. 8,849,305, the entire disclosure of which is hereby incorporated by reference for all purposes.
TECHNICAL FIELDThe current disclosure relates to mobile device location services and in particular to improving location estimation of co-located transceivers of sectored cell sites for location services.
BACKGROUNDMobile devices, such as smartphones, tablets and laptops location services enable location based applications or services to be provided on the devices. These services require that the mobile device determine their current location, or an estimate of the location using location technology such as a global positioning system (GPS) receiver. However a GPS receiver or signal may not always be available, or its accuracy too low due to the particular radio frequency environment, and an accurate location for the mobile device may be able to be determined.
It is possible to estimate a location of a mobile device based on a radio scene captured by the mobile device, however an accurate location of the associated transceivers is required to provide location estimate. The radio scene may comprise a plurality of cell identifiers (IDs) and associated received signal strength indicator (RSSI) value from cellular transceivers the mobile device is receiving signals from. If the locations of the transceivers are known, the location of the mobile device can be estimated using trilateration, or more generally n-lateration.
While the above technique for determining a cell site's location as a centroid of mobile device positions works well if the users providing their location information are evenly distributed about the transceiver of cell site, the technique will provide a location estimate with a larger error if the users are not evenly located about the transceiver of the cell site, as may be the case for co-located transceivers of sectored cell sites.
As described above, in order to provide a location service when GPS information is not available or is inaccurate from the mobile device, the location of cell sites must be known to use network based location techniques. Although the wireless carriers, or infrastructure service providers, that operate the wireless network will know the location of the cell sites to a high degree of accuracy and can use network based location techniques to determine a location of a mobile device, this information is often not available to third parties or applications that may wish to provide location services to mobile devices. As such, it is necessary to be able to accurately determine the location of cell sites in a network in order to provide location services without relying on service provider location information.
Therefore there is a need for a system and method for improved location estimates of co-located sectored cell sites.
Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
In accordance with the present disclosure, there is provided a method of improving a location estimate of a transceivers co-located at a sectored cell site, the method comprising: identifying a plurality of transceivers that are co-located at the sectored cell site; determining a location of a virtual transceiver as an average of respective location estimates of the plurality of identified transceivers; and assigning the determined location of the virtual transceiver to each of the transceivers determined to be co-located.
In accordance with the present disclosure, there is further provided an apparatus for estimating a transceiver's location comprising: at least one processing unit for executing instructions; and at least one memory unit for executing instructions, the instructions when executed by the at least one processing unit configuring the apparatus to perform a method of improving a location estimate of transceivers co-located at a sectored cell site, the executing instructions configuring the apparatus to: identify a plurality of transceivers that are co-located at the sectored cell site; determine a location of a virtual transceiver as an average of respective location estimates of the plurality of identified transceivers; and assign the determined location of the virtual transceiver to each of the transceivers determined to be co-located.
In accordance with the present disclosure, there is further provided a non-transitory computer readable memory storing computer executable instructions thereon that when executed by a processor perform a method of improving a location estimate of transceivers co-located at a sectored cell site, the method comprising: identifying a plurality of transceivers that are co-located at the sectored cell site; determining a location of a virtual transceiver as an average of respective location estimates of the plurality of identified transceivers; and assigning the determined location of the virtual transceiver to each of the transceivers determined to be co-located.
Although the following discloses example methods and apparatus including, among other components, software executed on hardware, it should be noted that such methods and apparatus are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of these hardware and software components could be embodied exclusively in hardware, exclusively in software, exclusively in firmware, or in any combination of hardware, software, and/or firmware. Accordingly, while the following describes example methods and apparatus, persons having ordinary skill in the art will readily appreciate that the examples provided are not the only way to implement such methods and apparatus.
It will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Also, the scope of the teachings provided herein is not considered to be limited to the specific description of the embodiments provided herein. Embodiments are described below, by way of example only, with reference to
As an example of unique identifiers, a transceiver may be uniquely identified by a Cell Global Identification (CGI) number. A CGI is composed of a number associated with the country, referred to as the mobile country code (MCC), a number associated with the carrier or network provider in the country, referred to as the mobile network code (MNC), a number associated with the area of the network provided by the carrier, referred to as the location area code (LAC) and a number identifying the transceiver within the location area, referred to as the cell ID. It will be appreciated that although a transmitter may be uniquely identified by a CGI number, it is not necessary for each transceiver to transmit the full CGI number in order for a mobile device to be able to uniquely identify the transceiver.
Regardless of the specific requirements of uniquely identifying transceivers, there is often a transceiver labelling format that is used, or attempted to be used, in labelling the unique transceiver IDs of the sectored cell site. For example, the transceiver 304a may have an ID of 123 1, transceiver 304b may have an ID of 123 2, and transceiver 304c may have an ID of 123 3.
Determining a location of a user 302 from the transceivers 304, 306, 308 of sectored cell sites is substantially similar to determining the location from omni-directional cell site transceivers, and in fact, the mobile device may not recognize that the transceivers are sectorized. The user 102 may capture radio scene information comprising the RSSI values and transceiver IDs and send the radio scene information to a location service that can retrieve the location of the transceivers and determine an estimate of the location of the mobile device. When the locations of the identified transceivers are known, the location service can provide a relatively accurate location estimate of the mobile device. However without accurate location information of the transceivers in the network, any location estimate based on the information will not be accurate.
Although the location of the sector transceiver 402a is described as being estimated as a centroid, it is contemplated that other methods of estimating transceiver locations from user reports are also possible. For example, the estimate may be based on finding a good convex hull of the measurements. Irrespective of the details of how the estimate is determined, the result will suffer from a bias into the cone of the sector, because of the asymmetric observation of the sector transceiver.
The antenna gain pattern of sector transceivers at a sectored cell site is highly peaked towards the respective sector. Hence even if users are physically present all around a sectored cell site, they will see the sector that they happen to be in. That is, the observation of transceivers of the sectored cell site will predominantly come only from the particular sector. This means that the centroid estimates of sector transceiver locations will be heavily biased into the cone of the respective sectors. Since the locations provided by the users are not evenly distributed around the sectorized transceiver, an estimate of the cell site location for the sector transceiver will have a relatively large error, in comparison to a transceiver with users evenly distributed about it. This error in cell site location can decrease the accuracy of a location of a mobile device estimated using the sectored cell site location estimates.
Effectively, the co-located sector transceivers of sectored a cell site are combined in a single virtual transceiver, which can be considered as if it were an omni-directional transceiver at the cell site. The information used for estimating the location of the individual sector transceivers can be used in estimating the location of the virtual transceiver, and since the group sector transceivers may provide the coverage similar to an omni directional cell site, the users contributing location information should be evenly distributed about the virtual transceiver. It should be appreciated, that the description of the virtual transceiver is intended for explanation, and a further transceiver is not actually created. Rather the virtual transceiver is a representation for the group of sector transceivers co-located at a sectored cell site. By utilizing location reports or updates provided by mobile devices which can provide location information, such as by using their GPS receiver, an accurate location mapping of cell sites in the network can be determined, regardless of if the cell sites comprise sector transceivers or not. The refined network location mapping can then be utilized to provide location estimation from the network for devices which do not have accurate location information.
Once the co-located sector transceivers are determined, the method determines a location estimate of a virtual transceiver that represents the co-located transceivers of the sectored cell site (604). The location of the virtual transceiver can be determined by averaging the location estimates of the individual transceivers of the virtual transceiver.
Once the location is determined for the virtual transceiver, it is assigned to each of the individual transceivers represented by the virtual transceiver (606). Assigning the location of the virtual transceiver to the location of the individual transceivers that are determined to be co-located at the sectored cell site may be accomplished in numerous ways. For example, the virtual transceiver location could replace the existing location estimate of each transceiver. Alternatively, the virtual transceiver location could be associated with the individual transceivers of the sectored cell site in addition to the original location estimates.
Accurate mobile device location estimates can be utilized to provide estimations of locations of transceivers of each sector of a cell site. The locations of all of the sector transceivers that are co-located at sectored cell site can then be utilized to refine the location of each individual sector transceiver. The transceiver location information can then be utilized by location services to provide network location services to devices which do not have accurate location information.
The method may begin with determining or updating location information for transceivers of cell sites (902). Determining or updating a transceiver's location information may be done using radio scene observations provided by mobile device in the network that have accurate location information of their own respective position using GPS location estimation. The mobile device can report the ID which is associated with a transceiver and the position of the mobile device when the ID was detected.
Transceivers that are within a co-location threshold of each other are grouped together into location groups (904), and then each location group is processed (906). Although depicted as being processed sequentially, it is contemplated that the location groups could be processed in parallel. Each location group is processed in order to group transceivers from the location group into one or more carrier network groups (908) so that transceivers of the same carrier network are grouped together. Carrier information may be provided in the transceiver ID, or may be associated with the transceiver ID. Once the transceivers are grouped into carrier groups, each carrier group can be processed (910). Although depicted as being processed sequentially, it is contemplated that the carrier groups could be processed in parallel.
For each carrier group, the IDs of the transceivers in the carrier group checked to see if the IDs are numbered or labelled consecutively or more broadly whether the labelling conforms to a co-located labelling format. If the transceivers aren't consecutively labelled (No at 912), then the transceivers in the carrier group are not considered as co-located and processing proceeds to get the next carrier group (920). If the transceivers are consecutively labelled (Yes at 912), it is determined if the number of transceivers in the carrier group matches an expected sector scheme (914) specifying an expected number of transceivers in a sectored cell site. For example, sector cell sites commonly use 2, 3 or 6 sectors. As such, the expected sector scheme may indicate that there are 2, 3 or 6 transceivers expected for a sectored cell site. If the number of sector transceivers in the carrier group do not match the expected sector scheme (No at 914), then the transceivers in the carrier group are not considered as being co-located at a sectored cell site and processing proceeds to get the next carrier group (920) for the location group. If the number of transceivers does match the expected sector scheme (Yes at 914), the transceivers of the carrier group are identified as a virtual transceiver (918). After identifying the transceivers of the carrier group as a virtual transceiver, any further carrier groups in the location group may be processed (920), and once all of the carrier groups in the current location group have been processed, another location group can be processed (922).
Once the method has identified the virtual transceivers, the location estimates of the sectorized transceivers the virtual transceivers can be updated, for example using one of the methods 700 or 800 described above.
In general, the method 1000 is a two-pass process. The first pass uses the observation data to estimate locations of each of the transceivers, which is used in grouping transceivers as virtual transceivers; the resultant location data after this first pass is depicted in
Returning to
Once a first pass has been made through the observation data, the location information is processed to identify co-located transceivers (1008). As depicted in
As is evident in
The method 1200 access the location and radio scene observation (1202). The location may be determined at the mobile devices in numerous ways, including the methods described herein, or through the use of GPS. The radio scene identifies the transceiver IDs of the transceivers that were seen by the mobile device at the indicated location. Each transceiver in the radio scene is processed (1204). For each transceiver in the radio scene, it is determined if the location associated with the transceiver in the observation would improve the current location estimate for the transceiver (1206). For example, if the error associated with the location of the observation is greater than the error associated with the current location estimate, the observation may not improve the location estimate. If the observation does not, or would not, improve the location estimate (No at 1206), the next transceiver in the radio scene is processed (1214). If the observation does, or would, improve the location estimate (Yes at 1206), the observation is used to update the location estimate. It is determined if the transceiver ID is associated with a virtual transceiver (1208), and if it is (Yes at 1208) the location of the observation is used to updated the location estimate of the virtual transceiver (1212) and the individual transceivers of the virtual transceiver, and the next transceiver in the radio scene is processed (1214). If the cell ID is not associated with a virtual transceiver (No at 1208), the location of the observation is used to update the location estimate of the transceiver (1210). Once the location estimate is updated, the next transceiver in the radio scene is processed (1214). If there are no further transceivers in the radio scene, the method is done (1216).
Since the location request included a radio scene, and resulted in an estimate of the location associated with the radio scene, the location may be used to update location estimates of transceivers in the radio scene. Although, the location estimate of the mobile device may have a larger error than the location estimate of the individual transceivers, it is possible that the location estimate could improve the location estimate for one or more of the transceivers in the radio scene. For example, if a new transceiver is added, an initial estimate of its location can be determined.
Each transceiver in the radio scene received in the location request is processed (1310). For each transceiver in the radio scene, it is determined if the determined location for the mobile device would improve the current location estimate for the transceiver (1312). For example, if the error associated with the determined location for the mobile device is greater than the error associated with the current location estimate, the determined location may not improve the location estimate. If the determined location does not, or would not, improve the location estimate (No at 1312), the next transceiver in the radio scene is processed (1320). If the determined location does, or would, improve the location estimate (Yes at 1312), the determined location is used to update the location estimate. It is determined if the transceiver ID is associated with a virtual transceiver (1314), and if it is (Yes at 1314) the determined location is used to updated the location estimate of the virtual transceiver (1318), and the next transceiver in the radio scene is processed (1320). If the transceiver ID is not associated with a virtual transceiver (No at 1320), the determined location is used to update the location estimate of the transceiver (1316). Once the location estimate is updated, the next transceiver in the radio scene is processed (1320). If there are no further transceivers in the radio scene, the method is complete.
The above has described various methods, apparatus and systems by way of examples. One skilled in the art will appreciate that the functionality described can be provided by one or more alternative embodiments based upon the current teachings.
Claims
1. A method of improving a location estimate of transceivers, the method comprising:
- identifying a plurality of transceivers co-located at a sectored cell site each having respective location estimates as a co-located group;
- determining a location of a virtual transceiver for the co-located group by using an average of the respective location estimates of each of the plurality of identified transceivers;
- assigning the determined location of the virtual transceiver to each of the transceivers of the co-located group at the sectored cell site; and
- grouping the plurality of transceivers into possible co-located groups based on a carrier identifier associated with the transceivers wherein the co-located groups are identified by a co-location labelling format that identifies one or more labelling formats used when assigning the unique identifier to the respective transceiver associated with the carrier identifier.
2. The method of claim 1, further comprising accessing the respective location estimates of each of the transceivers by respective unique identifier determined to be co-located from a data store.
3. The method of claim 1, wherein the location estimate of each of the transceivers is determined from location information provided from a plurality of mobile devices in communication with the respective transceiver.
4. The method of claim 3, wherein the location estimate of each of the transceivers comprises a respective error resulting from determining the location as a centroid of a plurality of mobile device locations unevenly distributed about the respective transceiver.
5. The method of claim 1, further comprising identifying each of a plurality of transceiverIDs as co-located transceivers by assigning a unique virtual transceiverID to the co-located transceivers.
6. The method of claim 1, further comprising, for each co-located group for a carrier identifier:
- determining a number of the plurality of transceivers with consistent transceiver IDs; and
- identifying the plurality of transceivers with consistent transceiver IDs as co-located transceivers based upon the labelling format.
7. An apparatus for estimating a transceiver's location comprising:
- at least one processing unit for executing instructions; and
- at least one memory unit for storing instructions, the instructions when executed by the at least one processing unit configuring the apparatus to:
- identify a plurality of transceivers co-located at a sectored cell site each having respective location estimates as a co-located group;
- determine a location of a virtual transceiver for the co-located group by using an average of the respective location estimates of each of the plurality of identified transceivers;
- assign the determined location of the virtual transceiver to each of the transceivers of the co-located group at the sectored cell site; and
- group the plurality of transceivers into possible co-located groups based on a carrier identifier associated with the transceivers wherein the co-located groups are identified by a co-location labelling format that identifies one or more labelling formats used when assigning the unique identifier to the respective transceiver associated with the carrier identifier.
8. The apparatus of claim 7, wherein the executed instructions further configure the apparatus to access the respective location estimates of each of the transceivers by respective unique identifier determined to be co-located from a data store.
9. The apparatus of claim 7, wherein the location estimate of each of the transceivers is determined from location information provided from a plurality of mobile devices in communication with the respective transceiver.
10. The apparatus of claim 9, wherein the location estimate of each of the transceivers comprises a respective error resulting from determining the location as a centroid of a plurality of mobile device locations unevenly distributed about the respective transceiver.
11. The apparatus of claim 7, further comprising identifying each of the plurality of transceiver IDs as co-located transceivers by assigning a unique virtual transceiver ID to the co-located transceivers.
12. A non-transitory computer readable memory storing computer executable instructions thereon that when executed by a processor perform:
- identifying a plurality of transceivers co-located at a sectored cell site each having respective location estimates as a co-located group;
- determining a location of a virtual transceiver for the co-located group by using an average of the respective location estimates of each of the plurality of identified transceivers; and
- assigning the determined location of the virtual transceiver to each of the transceivers of the co-located group at the sectored cell site; and
- grouping the plurality of transceivers into possible co-located groups based on a carrier identifier associated with the transceivers wherein the co-located groups are identified by co-location labelling format that identifies one or more labelling formats used when assigning the unique identifier to the respective transceiver associated with the carrier identifier.
13. The non-transitory computer readable memory of claim 12, further comprising instructions for accessing the respective location estimates of each of the transceivers by respective unique identifier determined to be co-located from a data store.
14. The non-transitory computer readable memory of claim 13, wherein the location estimate of each of the transceivers is determined from location information provided from a plurality of mobile devices in communication with the respective transceiver.
15. The non-transitory computer readable memory of claim 14, wherein the location estimate of each of the transceivers comprises a respective error resulting from determining the location as a centroid of a plurality of mobile device locations unevenly distributed about the respective transceiver.
16. The non-transitory computer readable memory of claim 12, further comprising instructions for identifying each of a plurality of transceiverIDs as co-located transceivers by assigning a unique virtual transceiverID to the co-located transceivers.
17. The non-transitory computer readable memory of claim 12, further comprising instructions for, for each co-located group for a carrier identifier:
- determining a number of the plurality of transceivers with consistent transceiver IDs; and
- identifying the plurality of transceivers with consistent transceiver IDs as co-located transceivers based upon the labelling format.
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Type: Grant
Filed: Sep 29, 2014
Date of Patent: Feb 23, 2016
Patent Publication Number: 20150087334
Assignee: BlackBerry Limited (Waterloo)
Inventors: Anand Ravindra Oka (Redmond, WA), Christopher Harris Snow (Santa Clara, CA), Sean Bartholomew Simmons (Waterloo)
Primary Examiner: Khai M Nguyen
Application Number: 14/500,116
International Classification: H04W 24/00 (20090101); H04W 4/02 (20090101);