Asynchronous triggering of mobile station location estimation

• US 8,588,822 B1
• Filed: 01/11/2013
• Issued: 11/19/2013
• Est. Priority Date: 01/11/2013
• Status: Active Grant

• Current Assignee: Polaris Wireless Incorporated
• Original Assignee: Polaris Wireless Incorporated
• Inventors: Bhattacharya, Tarun Kumar, Patel, Mahesh B.
• Primary Examiner(s): Eng, George
• Assistant Examiner(s): HUYNH, NAM TRUNG
• Application Number:
  US13/739,911
• Time in Patent Office: 312 Days
• Field of Search: 4554561-457
• US Class Current: 455/456.5
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/02527 Detecting or resolving anomalies in the radio frequency fingerprints of the radio-map
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A system and method are disclosed for triggering location estimation of mobile stations in a geographic region of interest. The disclosed system includes a list of International Mobile Subscriber Identities (“IMSI”) used to track which mobile stations are to have location estimates generated, a database of Network Measurement Reports (“NMR”) used for generating the location estimates, and a location engine. The system operates as a group of concurrently executing processes that i) process IMSIs and NMRs that are extracted by and received from probes that monitor communication links; ii) generate location estimates of mobile stations in the region of interest, based on a sequential indexing of the IMSI list; iii) maintain the freshness of the NMR database; and iv) maintain the freshness of the IMSI list. These processes operate such that the triggering of the location estimations occurs asynchronously with respect to the detection of information on the communication links.

Claims

1. A method for locating one or more mobile stations in a geographic region of interest served by a wireless telecommunications network, the method comprising:

storing, by a data-processing system, a list of International Mobile Subscriber Identities (IMSI) that are present in the list according to a predetermined ordering, wherein the IMSIs in the list identify mobile stations for which location estimates are to be generated;

monitoring, by the data-processing system, a nonempty set of predetermined communication links in the wireless telecommunications network, wherein the set of communication links comprise at least an Abis link, and wherein the communication links are monitored for i) messages that comprise IMSIs and ii) Network Measurement Report (NMR) messages;

generating, by the data-processing system, location estimates for the mobile stations that are identified by the IMSIs in the list, wherein the generating of each location estimate is triggered based on sequentially indexing each IMSI in the list, and wherein the location estimates are based the NMR messages;

deleting, by the data-processing system, a first IMSI from the list when it is determined that the mobile station identified by the first IMSI is no longer available in the geographic region of interest;

detecting, by the data-processing system, a first NMR message on a communication link of the monitored set of communication links;

storing in a memory, by the data-processing system, the detected first NMR message;

deleting, from the memory, a second NMR message when the second NMR message has been stored in the memory for at least a predetermined time interval; and

transmitting a mobile terminal location request (MTLR) to a first mobile station, wherein the detecting of the first NMR message is based on the transmitting of the MTLR, and wherein the transmitting of the MTLR is based on whether any NMR message that corresponds to the first mobile station is stored in the memory.