Location update protocol

• US 6,810,259 B1
• Filed: 12/14/2000
• Issued: 10/26/2004
• Est. Priority Date: 12/16/1999
• Status: Expired due to Fees

• Current Assignee: UTStarcom Incorporated (UTStarcom Holdings Corp.)
• Original Assignee: UTStarcom Incorporated (UTStarcom Holdings Corp.)
• Inventors: Zhang, Greg
• Primary Examiner(s): Appiah, Charles
• Assistant Examiner(s): Iqbal, Khawar
• Application Number:
  US09/738,203
• Time in Patent Office: 1,412 Days
• Field of Search: 455/456.1, 455/456.5, 455/435.1, 455/436, 455/440, 455/448, 455/433, 455/432.3, 455/411, 455/410, 455/412.1, 711/130, 711/141, 711/119, 709/213, 345/811
• US Class Current: 455/456.5
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04W 8/18 Processing of user or subscriber data, e.g. subscribed services, user preferences or user profiles; Transfer of user or subscriber data
• CPC Class Codes: H04W 8/20 Transfer of user or subscriber data
• CPC Class Codes: H04W 92/20 between access points

Abstract

A location update protocol is provided for use in a mobile communications network having a distributed cache for managing subscriber profile information associated with each of a plurality of subscribers of the network. The network includes a plurality of base stations each including a memory unit having a local database for storing: a local subscriber list including a plurality of locally owned cache entries each having an associated subscriber key value, and an associated locally owned subscriber profile; and a global subscriber list including a plurality of global cache entries each having an associated subscriber key value, and an associated location value indicating a node in the network at which an associated subscriber profile is stored. Each of the base stations is operative to transfer and copy selected ones of the cache entries to other ones of the base stations for the purposes of managing and accessing the distributed cache. Each of the base stations is further operative to access an associated mirror base station list indicating at least one associated mirror one of the base stations. The local database of each of the base stations further provides for storage of a mirror subscriber profile list including a plurality of mirror cache entries each having an associated subscriber key value, and an associated mirror subscriber profile. Each of the base stations transfers mirror copies of the associated locally owned cache entries to each of the associated mirror base stations in accordance with the protocol.

Claims

1. A mobile communications network providing a distributed cache for managing subscriber profile information associated with each of a plurality of subscribers of the network, comprising:

a plurality of base stations communicatively coupled with each other via a backbone of the network, each of said base stations having an associated coverage area, and being operative to communicate via wireless communication links with subscribers using mobile hosts located within said associated coverage area, each of said base stations including a memory unit having a local database for storing, each of said base stations is operative to transfer and copy profiles to other ones of said base stations in accordance with a distributed cache synchronization protocol established by neighbor proximity,

a local subscriber list including a plurality of locally owned cache entries each having an associated subscriber key value, and an associated locally owned subscriber profile, and

a global subscriber list including a plurality of global cache entries each having an associated subscriber key value, and an associated location value indicating a node in the network at which an associated subscriber profile is stored;

wherein each of said base stations is operative to transfer and copy selected ones of said cache entries to other ones of said base stations via said backbone for the purposes of managing and accessing said distributed cache, and for supporting communications applications in the network.

2. A mobile communications network as recited in claim 1 wherein each of said base stations is operative in accordance with said protocol to transfer a particular one of said cache entries to a new owner one of said base stations via said backbone upon a determination that ownership of said particular cache entry has been transferred to said new owner base station.

3. A mobile communications network as recited in claim 1 wherein each of said base stations is operative in accordance with said protocol to transfer a particular one of said cache entries to a new owner one of said base stations via said backbone upon execution of an associated handoff procedure.

4. A mobile communications network as recited in claim 1 wherein each of said base stations is operative in accordance with said protocol to copy a particular one of said cache entries to a requesting one of said base stations via said backbone in response to receiving a cache entry copy request message from said requesting base station.

5. A mobile communications network as recited in claim 1 wherein each of said base stations is operative in accordance with said protocol to send cache entry copy request messages requesting associated cache entries in order to support call processing operations.

6. A mobile communications network as recited in claim 1 wherein:

each of said base stations is operative to access an associated mirror base station list indicating at least one associated mirror one of said base stations;

said local database of each of said base stations further provides for storage of a mirror subscriber profile list including a plurality of mirror cache entries each having an associated subscriber key value, and an associated mirror subscriber profile; and

each of said base stations is operative to periodically transfer mirror copies of each of said associated locally owned cache entries to each of said associated mirror base stations via said back bone in accordance with said protocol.

7. A mobile communications network as recited in claim 1 wherein:

each of said base stations is operative to access an associated mirror base station list indicating at least one associated mirror one of said base stations;

said local database of each of said base stations further provides for storage of a mirror subscriber profile list including a plurality of mirror cache entries each having an associated subscriber key value, and an associated mirror subscriber profile;

each of said base stations is operative to periodically transfer mirror copies of each of said associated locally owned cache entries to each of said associated mirror base stations via said back bone in accordance with said protocol; and

each of said mirror base stations is responsive to the received mirror copies of cache entries, and operative to store said mirror copies in said local database, and also operative to revise said mirror subscriber profile list to include said received mirror copies;

whereby if ownership of a particular one of said subscriber profiles associated with a particular one of said hosts is transferred from an old one of said base stations to a new mirror base station associated with said old base station as a result of a hand off procedure executed while said particular host is engaged in a communication session controlled by said old base station, then transfer of control of said communication session to said new mirror base station is facilitated by said new mirror base station already having a copy of said particular subscriber profile.

8. A mobile communications network as recited in claim 1 wherein said network further comprises:

a central database system including a central server, and a central database for storing subscriber profile information associated with each of said subscribers, and wherein said central database also stores the mirror base station lists associated with each one of said base stations; and

wherein each of said base stations is operative to access said associated mirror base station list by querying said central server.

9. A mobile communications network as recited in claim 1 wherein each of said subscriber profile key values includes a link layer identification value associated with one of said mobile hosts, and wherein each of said local subscriber list, said global subscriber list, and said mirror subscriber list may be searched by said base station using the link layer identification values.

10. A mobile communications network as recited in claim 9 wherein each of said subscriber profile key values further includes a telephone number associated with said associated subscriber, and wherein each of said local subscriber list, said global subscriber list, and said mirror subscriber list may be searched by said associated base station using the telephone numbers.

11. A mobile communications network as recited in claim 1 wherein said network further comprises:

a central database system including a central server, and a central database for storing subscriber profiles associated with each of said subscribers; and

wherein updates to subscriber profiles associated with subscribers of the network may be initiated at either of said central database system, or one of said mobile hosts.

12. A mobile communications network as recited in claim 11 wherein each of said subscriber profiles includes a version value for tracking said updates to said profiles.

13. A mobile communications network as recited in claim 11 wherein each of said subscriber profiles includes a version value for tracking said updates to said profiles as said updates are initiated at either of said central database system, or one of said mobile hosts.

14. A mobile communications network as recited in claim 13 wherein said version value of each of said subscriber profiles comprises:

a major version number which is increased upon commitment of an update of an associated profile to said central database; and

a minor version number which is increased upon commitment of an update of said associated profile to said local database.

15. A mobile communications network as recited in claim 14 wherein each of said base stations is operative to determine and resolve conflicts related to the contents of updated profiles, said conflicts arising as a result of a first update being initiated by said central database system, and a second update being initiated by one of said mobile hosts.

16. A mobile communications network as recited in claim 14 wherein each of said base stations is operative to determine and resolve said conflicts by comparing the version values of multiple conflicting copies of an associated profile for which a conflict has arisen.

17. In a base station of a mobile communications network having a plurality of base stations communicatively coupled with each other via a backbone of the network, each of said base stations having an associated coverage area, and being operative to communicate via wireless communication links with subscribers using mobile hosts located within said associated coverage area, each of said base stations including a memory unit having a local database, a method of providing a distributed cache for managing subscriber profile information associated with each

of the subscribers of the network, comprising the steps of:

storing in said local database,

a local subscriber list including a plurality of locally owned cache entries each having an associated subscriber key value, and an associated locally owned subscriber profile, and

a global subscriber list including a plurality of global cache entries each having an associated subscriber key value, and an associated location value indicating a node in the network at which an associated subscriber profile is stored;

determining whether ownership of a particular one of said locally stored subscriber profiles has been transferred to a new owner one of said base stations; and

if said ownership of said particular subscriber profile has been transferred to a new owner one of said base stations, transferring said particular cache entry to said new owner base station via said backbone in accordance with a distributed cache synchronization protocol established by neighbor proximity.

18. In a base station of a mobile communications network as recited in claim 17 further comprising the steps of:

accessing an associated mirror base station list identifying at least one associated mirror one of said base stations;

storing and managing a mirror subscriber profile list in said local database, said mirror subscriber profile list including a plurality of mirror cache entries each having an associated mirror subscriber profile, and an associated subscriber key value; and

transferring mirror copies of each of said locally owned cache entries to each of said associated mirror base stations via said back bone in accordance with said protocol.

19. In a base station of a mobile communications network as recited in claim 18 wherein said network also comprises a central database system including a central server, and a central database for storing subscriber profile information associated with each of said subscribers, and wherein said central database also stores the mirror base station lists associated with each one of said base stations, further comprising the step of accessing said associated mirror base station list by querying said central server.

20. In a base station of a mobile communications network as recited in claim 18 wherein each of said subscriber profile key values includes a link layer identification value associated with one of said mobile hosts, said method further comprising the step of:

searching each of said local subscriber list, said global subscriber list, and said mirror subscriber list using a link layer identification value.

21. In a base station of a mobile communications network as recited in claim 20 wherein each of said subscriber profile key values includes a telephone number associated with one of said subscribers, said method further comprising the step of:

searching each of said local subscriber list, said global subscriber list, and said mirror subscriber list using a telephone number.

22. In a base station of a mobile communications network as recited in claim 20 further comprising the steps of:

receiving a registration message from a registering one of said hosts, said received registration message including a received link layer ID value;

searching said local subscriber list using said received link layer ID value to determine if a profile associated with said registering host is indicated in said local subscriber list; and

if said profile associated with said registering host is indicated in said local subscriber list, accessing said locally stored profile associated with said registering host.

23. In a base station of a mobile communications network as recited in claim 22 wherein if said profile associated with said registering host is not indicated in said local subscriber list, said process further comprises the steps of:

searching said mirror subscriber list using said received link layer ill value to determine if said profile associated with said registering host is indicated in said mirror subscriber list; and

if said profile associated with said registering host is indicated in said mirror subscriber list,

updating said local subscriber list by adding a cache entry including said profile associated with said registering host to said local subscriber list,

sending a cache entry transfer request to the current owner of the profile; and

announcing to other ones of said base stations that said profile associated with

said registering host is owned by said base station in accordance with said protocol.

24. In a base station of a mobile communications network as recited in claim 23 wherein if said profile associated with said registering host is not indicated in said local subscriber list, said

process further comprises the steps of:

if said profile associated with said registering host is not indicated in either of said local subscriber list or said mirror subscriber list,

searching said global subscriber list using said received link layer ill value to determine if said profile associated with said registering host is indicated in said global subscriber list, and

if said profile associated with said registering host is indicated in said global

subscriber list,

reading the location value associated with said profile to determine the node in the network at which said profile is stored, and

retrieving said profile associated with said registering host from said node at which said profile is stored.

25. In a base station of a mobile communications network as recited in claims 23 wherein said step of retrieving said profile associated with said registering host comprises:

sending a cache entry transfer request message to said node at which said profile is stored in accordance with said protocol, said cache entry transfer request message indicating said

profile associated with said registering host; and

receiving a cache entry transfer message from said node in accordance with said protocol, said cache entry transfer message carrying said profile associated with said registering host.

26. In a base station of a mobile communications network as recited in claims 23 wherein if said profile associated with said registering host is not indicated in either of said local subscriber list or said mirror subscriber list, and said profile associated with said registering host is

indicated in said global subscriber list, said method further comprises the steps of:

updating said local subscriber list by adding a cache entry including said profile associated with said registering host to said local subscriber list;

copying said profile associated with said registering host to said associated mirror sites in accordance with said protocol; and

announcing in accordance with said protocol to other ones of said base stations that said profile associated with said registering host is owned by said base station.

27. In a base station of a mobile communications network as recited in claim 20 further comprising the step of:

if said link layer identification value is not found in said local subscriber list, said global subscriber list, and said mirror subscriber list,

sending a message to retrieve said profile from the central database system, copying said profile associated with said registering host to said associated mirror

sites in accordance with said protocol, and

announcing to other ones of said base stations that said profile associated with said registering host is owned by said base station in accordance with said protocol.

28. In a base station of a mobile communications network as recited in claim 27 wherein said step of announcing to other ones of said base stations that said profile associated with said registering host is owned by said base station comprises transmitting a cache entry

announcement message via said network in accordance with said protocol.

29. In a base station of a mobile communications network as recited in claim 17 further comprising the steps of:

accessing an associated mirror base station list identifying at least one associated mirror one of said base stations;

storing and managing a mirror subscriber profile list in said local database, said mirror subscriber profile list including a plurality of mirror cache entries each having an associated mirror subscriber profile, and an associated subscriber key value;

transferring mirror copies of each of said locally owned cache entries to each of said associated mirror base stations via said back bone in accordance with said protocol; and

receiving mirror copies of cache entries, and storing said mirror copies in said local database, and also revising said mirror subscriber profile list to include mirror cache entries associated with said received mirror copies;

whereby if ownership of a particular one of said subscriber profiles associated with a particular one of said hosts is transferred from an old one of said base stations to a new mirror base station associated with said old base station as a result of a hand off procedure executed while said particular host is engaged in a communication session controlled by said old base station, then transfer of control of said communication session to said new mirror base station is facilitated by said new mirror base station already having a copy of said particular subscriber profile.

30. In a base station of a mobile communications network as recited in claim 17 wherein each of said subscriber profiles includes a version value for tracking updates to the profiles, said version value including a major version number which is increased upon commitment of an update of an associated profile to said central database, and a minor version number, further comprising the step of:

increasing the minor version number upon commitment of an update of the associated profile to said local database.

31. In a base station of a mobile communications network as recited in claim 17 wherein said network further comprises a central database system including a central server, and a central database for storing subscriber profiles associated with each of said subscribers, and wherein conflicts may arise between updates of profiles initiated by a host and by the central database system, said method further comprising the steps of:

receiving a command for updating a particular subscriber profile from one of said mobile hosts via a wireless link;

updating contents of said particular subscriber profile to create a first updated version of said particular subscriber profile, and storing said first updated particular subscriber profile in the local database;

receiving an updated profile message from the central database system, said updated profile message including a second updated version of said particular subscriber profile;

comparing the contents of said first updated version of said particular subscriber profile to contents of said second updated version;

determining is there is a conflict between the contents of said first updated version and the contents of said second updated version; and

if there is a conflict between the contents of said first updated version and the contents of said second updated version, resolving the conflict.

32. In a base station of a mobile communications network as recited in claim 17 further comprising the steps of:

determining that a particular one of said locally owned subscriber profiles has been

handed off to a new one of said base stations; and

transferring said particular subscriber profile to said new base station via a cache entry transfer message in accordance with said protocol.

33. In a base station of a mobile communications network as recited in claim 32 further comprising the step of:

announcing to other ones of said base stations via a cache entry withdrawal message that said particular profile is no longer owned by said base station.