Distributed subscriber data management in wireless networks from a central perspective

• US 6,091,952 A
• Filed: 05/29/1997
• Issued: 07/18/2000
• Est. Priority Date: 08/30/1996
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Nortel Networks Corporation
• Inventors: Xu, Jian Ming, Sollee, Patrick N., Bryant, Adam E. T.
• Primary Examiner(s): Trost, William G.
• Assistant Examiner(s): GELIN, JEAN ALLAND
• Application Number:
  US08/864,926
• Time in Patent Office: 1,146 Days
• Field of Search: 455/422, 455/432, 455/435, 455/433, 455/436, 455/443, 455/444, 455/456
• US Class Current: 455/433
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks

Abstract

A system and method for increasing capacity of a cellular system by reducing call overhead processing and transmission congestion previously required in updating a subscriber'"'"'s mobile station data position as the subscriber moves among locations within a geographic area served by a network service provider is presented. A predetermined N number of copies of mobile station subscriber data is distributed among multiple Visiting Location Registers (VLRs) within the area served by a cellular system. Unlike previous systems, when mobile stations traverse location boundaries, the current VLR corresponding to the current location does not need to update the subscriber data if that data has not changed since the subscriber was last in that location.

Claims

1. A method for managing registration of mobile stations in a cellular communication system including a central switching center operably connected to a public switched telephone network, a plurality of transceiver stations connected to the central switching center for communicating with said mobile stations, and a registration processor operably connected to the central switching center including a plurality of first registers and a second register, the method comprising the steps of:

receiving a location update request from a visited first register at said second register;

determining whether a data required parameter is included in said location update request;

if said data required parameter is included and if said received data required parameter indicates subscriber data is required at said visited first resister, downloading subscriber data to said visited first register; and

,

if said data required parameter is included and if said received data required parameter indicates subscriber data is not required at said visited first register, not downloading subscriber data to said visited first register.

2. The method of claim 1 further including the step of:

if said data required parameter is present and indicates data is required, modifying second register data to indicate said visited first register received data and sorting said second register data chronologically.

3. The method of claim 2 further including the steps of:

sending update location confirmation to said visited first register; and

optionally sending a clear location request to a previous predetermined first register.

4. The method of claim 1 further including the step of:

modifying said second register data to update said visited first register received data if said second register contains data concerning said visited first register, and sorting said second register data chronologically if said data required parameter is present and indicates data is not required.

5. The method of claim 4 further including the steps of:

sending an update location acceptance to said visited first register; and

optionally sending a clear location request to said previous predetermined first register.

6. The method of claim 4 further including the steps of:

sending subscriber data to said visited first register if said second register does not contain data concerning said visited first register and if said data required parameter is present and indicates data is not required; and

sorting said second register data chronologically.

7. The method of claim 6 further including the step of sending a clear location request to said previous first register if said second register does not contain information concerning data concerning said previous first register.

8. The method of claim 7 further including the step of determining whether said second register data exceeds a predetermined threshold N, where N is a positive whole number of chronologically ordered data.

9. The method of claim 8 further including the step of removing the oldest chronologically ordered data from said second register when said predetermined threshold N is exceeded.

14. The method as claimed in claim 1, including the step of:

if said data required parameter is not included, then downloading subscriber data to said visited first register.

10. A cellular communication system comprising:

a gateway central switching controller operably connected to a public switched telephone network;

a plurality of central switching controllers operably connected to said gateway central switching controller;

a plurality of transceiver stations for communicating with a mobile station traveling among predetermined geographic areas, each transceiver station associated with one of said geographic areas and operably connected to one of said central switching controllers;

a registration processor, including a home location register, associated with the gateway central switching controller, for storing mobile station related data including a list of geographic areas visited by said mobile station;

a plurality of visitor location registers, each visitor location register corresponding to a particular one of said central switching controllers, for storing temporary mobile station data;

means for receiving a location update request from a visited visitor location register at said home location register;

means for downloading subscriber data to said visited visitor location register if a data required parameter is present and indicates data is required and modifying said home location register data to indicate said visited visitor location register received data and sorting said home location register data chronologically; and

,

means for modifying said home location register data to indicate said visited visitor location register received data and sorting said home location register data chronologically without downloading subscriber data to said visited visitor location register if said data required parameter indicates data is not required.

11. The cellular communication system of claim 10 further including:

means for sending update location confirmation to said visited visitor location register; and

means for optionally sending a clear location request to a previous predetermined visitor location register.

12. The cellular communication system of claim 10 further including means for determining whether said home location register data exceeds a predetermined threshold N, where N is a positive whole number of chronologically ordered data.

13. The cellular communication system of claim 10 further including means for removing the oldest chronologically ordered data from said home location register when said predetermined threshold N is exceeded.

15. A method of managing registration of mobile stations in a cellular communication system including a central switching center operably connected to a public switched telephone network, a plurality of transceiver stations connected to the central switching center for communicating with said mobile stations, and a registration processor operably connected to the central switching center including a plurality of visitor location registers and a home location register, the method comprising the steps of:

maintaining in said home location register a list of visitor location registers visited by a mobile station;

receiving at said home location register a location update request from a visited visitor location register;

determining whether a data required parameter is included in said location update request;

downloading subscriber data from said home location register to said visited visitor location register if said data required parameter is present and indicates data is required; and

,

updating said list based upon said location update request.

16. The method as claimed in claim 15, including the step of:

if the data required parameter is not included, then downloading subscriber data from said home location register to said visited visitor location register.

17. The method as claimed in claim 16, including the step of:

sending update location results to said visited visitor location register.

18. The method as claimed in claim 17, including the steps of:

determining if a next previous visited visitor location register is in said list; and

,

sending a cancel location request to said next previous visited visitor location register.

19. The method of claim 15, wherein said step of updating said list includes the step of:

marking said visited visitor location register in said list as the most recently visited visitor location register and sorting said list chronologically.

20. The method as claimed in claim 19, including the further step of:

if said data required parameter is included in said location update request, determining if said visited visitor location register is in said list.

21. The method as claimed in claim 20, including the step of:

if said visited visitor location register is in said list, marking said visited visitor location register in said list as the most recently visited visitor location register; and

,

sorting said list chronologically.

22. The method as claimed in claim 20, including the steps of:

if said visited visitor location register is not in said list, downloading subscriber data from said home location register to said visited visitor location register;

marking said visited visitor location register in said list as the most recently visited visitor location register; and

,

sorting said list chronologically.

23. The method as claimed in claim 19, including the step of:

determining if said visited visitor location register is in said list.

24. The method as claimed in claim 23, including the step of:

if said visited visitor location register is in said list, marking said visited visitor location register in said list as the most recently visited visitor location register; and

,

sorting said list chronologically.

25. The method as claimed in claim 23, including the steps of:

if said visited visitor location register is not in said list, downloading subscriber data from said home location register to said visited visitor location register;

adding said visited visitor location register to said list;

marking said visited visitor location register in said list as the most recently visited visitor location register; and

,

sorting said list chronologically.

26. The method as claimed in claim 25, including the step of:

determining whether said list includes a number of visited visitor location registers greater than a predetermined a positive whole number N.

27. The method as claimed in claim 26, including the step of:

removing the oldest chronologically ordered visited visitor location register from said list when said number N is exceeded.

28. The method as claimed in claim 27, including the step of:

sending a clear location request from said home location register to said oldest chronologically ordered visited visitor location register.