Method and system for handover in cellular wireless using route programming and training processes

• US 20070142050A1
• Filed: 12/19/2005
• Published: 06/21/2007
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Duxbury, Guy, Marcanti, Larry, Handforth, Martin
• Granted Patent: US 8,160,613 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/322 by location data

Abstract

A method and system for managing handover where a database that receives location information about a moving object includes information regarding which base station is used in a current radio link connection and which base stations were used from historic radio link connections. Using the base station radio link history of the object and an electronic map, a processor coupled to the memory of the database selects which physical path the moving object is using. Upon matching the object'"'"'s path with a history of path routes on the list, the processor will apply an optimized handoff sequence to the moving object. The optimized route can be derived from an algorithm that processes previous historical data from moving objects traveling on the same route. Methods of providing the location of moving objects via location sensors may be used to provide the database with higher resolution information about a moving object'"'"'s location on an electronic map and allow further enhancement of the handoff optimization. Generally, location data is used to quickly determine which route the moving object is using and more quickly assign an optimized handoff sequence. Historical data along known routes can include time and spatial information to be processed by the routing algorithm. The database may reside in a central location or within each moving object or a combination of both.

Claims

1. A method of managing handover within a radio cellular environment, said method comprising:

determining an identification of a mobile station that is known to normally follow a predetermined route corresponding to said identification;

comparing said identification with a database having stored maps of known route segments including a list of base stations along each of said known route segments; and

assigning a preferred sequence of base stations corresponding to one or more of said known route segments along said predetermined route.

2. The method as claimed in claim 1, wherein said identification forms information including ongoing location and relative-location information over absolute time and relative time including one or more units of time.

3. The method as claimed in claim 2, wherein said information includes a unique route identifier.

4. The method as claimed in claim 3, wherein said information further includes geographical location information corresponding to said mobile station.

5. The method as claimed in claim 4, wherein said information further includes time of day information.

6. The method as claimed in claim 5, wherein said information further includes speed information corresponding to movement of said mobile station.

7. The method as claimed in claim 6, wherein said information further includes directional information corresponding to directional movement of said mobile station.

8. The method as claimed in claim 7, wherein said directional information is obtained from a directional indication mechanism on board a vehicle upon which said mobile station resides.

9. The method as claimed in claim 8, wherein said method further includes storing locally on board said vehicle said maps that include said known route segments corresponding to said preferred sequence of base stations.

10. The method as claimed in claim 9, wherein said database is centrally stored at a central server.

11. A method of optimizing a managed handover technique within a radio cellular environment, said method comprising:

determining an identification of a mobile station traveling along a path, said mobile station having no previous history of base station connectivity;

as said mobile station establishes a connection with a base station, associating, based upon said base station being used by said mobile station, said identification with a known route selected from a database having stored maps of more than one said known route including a list of base stations along each said known route;

as said mobile station disconnects from said base station and connects to a subsequent base station, storing historical information regarding said base station and said subsequent base station;

comparing said base station and said subsequent base station to said list of base stations along said known route in order to identify one or more of said known routes that include both said base station and said subsequent base station;

repeating said storing and comparing steps for further subsequent base stations, until only one of said known routes remains and corresponds to said path traveled by said mobile station;

determining whether a direction of travel of said mobile station along said path is forward or reverse along said known route that corresponds to said path;

identifying one of said stored maps from said database that correlates to both said direction of travel and said known route remaining that corresponds to said path traveled; and

assigning a preferred sequence of base stations corresponding to said one of said stored maps for all further connections with said mobile station along said path.

12. The method as claimed in claim 11, wherein said preferred sequence of base stations is derived from long term historical data for travel of said mobile station along one or more said path.

13. The method as claimed in claim 11, wherein said preferred sequence of base stations is derived from an arbitrary visual inspection of geographical maps that include available routes traveled by said mobile station and available base stations.

14. The method as claimed in claim 11, wherein said preferred sequence of base stations is derived from algorithms to calculate the optimized sequence.

15. The method as claimed in claim 14, wherein said preferred sequence of base stations is derived by a centralized database that tracks network throughput, each base station throughput, and each mobile station throughput while managing base station connectivity to reduce data throughput congestion.

16. A system for managing handover in a radio cellular environment, said system comprising:

a centralized communications center having a base transceiver, a central server, and a database;

a mobile station having one or more transceivers capable of communication with said centralized communications center via one or more base stations, said mobile station being assigned a preferred sequence of said one or more base stations corresponding to one or more known route segments along a predetermined route followed by said mobile station.

17. The system as claimed in claim 16, wherein said preferred sequence of said one or more base stations is selected from a plurality of possible sequences and said plurality of possible sequences is stored in said database.

18. The system as claimed in claim 17, wherein said preferred sequence is stored within a memory of said mobile station.

19. The system as claimed in claim 18, wherein said mobile station further includes a location detection means for determining the location of said mobile station.

20. The system as claimed in claim 19, wherein said location detection means is a global positioning device.

21. A method of managing handover within a radio cellular environment, said method comprising:

determining an identification of a mobile station that is known to normally follow an indeterminate route corresponding to said identification;

comparing said identification with a database having stored maps of regions known to provide optimum hard handover and regions known to provide optimum soft handover; and

initiating the handover process when the mobile station is within said region.

22. The method as claimed in claim 21, wherein said identification forms information including ongoing continuous samples in time of absolute location.

23. The method as claimed in claim 21, wherein said identification forms information including ongoing discontinuous samples in time of absolute location.

24. The method as claimed in claim 21, wherein said identification forms information including ongoing continuous samples in time of relative location.

25. The method as claimed in claim 21, wherein said identification forms information including ongoing discontinuous samples in time of relative location.

26. The method as claimed in claim 22, wherein the said identification forms information regarding the direction of the mobile station relative to the nearest handover region within the database map of handover regions.

27. A method of optimizing a location of handover regions on a database map, said method comprising:

utilizing past historical data of previous base station radio links with mobile stations traveling pre-determined routes with associated information of mobile station velocity; and

selecting optimum handover regions for slow and fast velocities such that regions causing short durations of handovers are eliminated.

28. The method of claim 27 wherein said handover region is specific to hard handover and soft handover locations.

29. The method of claim 28 wherein said handover region for hard handover is defined as a boundary line and said regions are a geophysical location having geophysical location points.

30. The method of claim 28, wherein said handover region for soft handover is defined as an area enclosed by a boundary of geophysical location points.