Network resource sharing during handover of a mobile station between cellular wireless networks

• US 6,799,039 B2
• Filed: 04/13/2001
• Issued: 09/28/2004
• Est. Priority Date: 04/17/2000
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Wu, Geng, Fong, Mo-Han
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): NGUYEN, JOSEPH D
• Application Number:
  US09/835,035
• Publication Number:
  US 20010036830A1
• Time in Patent Office: 1,264 Days
• Field of Search: 455/436, 455/440, 455/437, 455/439, 455/438, 455/442, 455/428, 455/445, 455/443, 455/560, 455/561, 455/552.1, 455/555, 455/556.1, 455/554--, 370/331, 370/338
• US Class Current: 455/436
• CPC Class Codes: H04W 36/0066 of control information between different types of networks in order to establish a new radio link in the target network

Abstract

System components of cellular wireless networks are shared during and after a mobile station handover from a first cellular wireless network (system A) to a second cellular wireless network (system B). According to one aspect, layer 2/3 call control functions are anchored in a base station controller (BSC) of system A, even after a data communication is handed over from system A to system B. According to another aspect, a link layer supporting the data communication is anchored in the BSC of system A servicing the data communication. In this case, the BSC of system A interfaces with a serving BTS of system B to service the ongoing data communication. According to still another aspect, the link layer is handed over to system B but the link layer of system B continues to use a link layer transmit buffer of system A that remains in the servicing BSC of system A.

Claims

1. A method for servicing a data communication for a mobile station before, during and after handover of the mobile station from a first wireless network to a second wireless network, the method comprising:

centralized link layer protocol functions of a base station controller of the first wireless network and distributed link layer protocol functions of a base station of the first wireless network servicing the mobile station before handover;

initiating a handover of the mobile station from the first wireless network to the second wireless network;

determining a first set of data communication functions to be serviced by the first wireless network after handover, including the centralized link layer protocol functions of the base station controller of the first wireless network;

determining a second set of data communication functions to be serviced by the second wireless network after handover, wherein the second set of data communication functions include at least wireless link functions and distributed link layer protocol functions of a base station of the second wireless network;

handing over the mobile station from the first wireless network to the second wireless network; and

servicing the mobile station after handover using the first set of data communication functions provided by the first wireless network and the second set of data communication functions performed by the second wireless network.

2. The method of claim 1, wherein the second set of data communication functions comprises call control functions.

3. The method of claim 1, further comprising the base station controller of the first wireless network communicatively coupling to the base station of the second wireless network via a radio access network and servicing the data communication there through.

4. The method of claim 1, wherein the first set of data communication functions includes link layer data buffering functions.

5. The method of claim 1, wherein the second set of data communication functions includes link layer data buffering functions.

6. The method of claim 1, wherein the second set of data communication functions includes call control functions.

7. The method of claim 6, wherein the call control functions include layer 2/3 call control functions.

8. The method of claim 1, wherein servicing the mobile station after handover includes routing the data communication from a component of the first wireless network to a component of the second wireless network.

9. The method of claim 8, wherein the data communication is routed from the base station controller of the first wireless network to the base station of the second wireless network.

10. The method of claim 9, wherein at least a portion of a data routing path servicing the data communication remains after handover.

11. A base station controller of a first wireless network, the base station controller comprising:

a packet data serving node interface;

a base station interface that interfaces the base station controller to a plurality of base stations; and

at least one digital processor coupled to the packet data serving node interface and the base station interface that executes software instructions causing the base station controller to;

service a data communication for a mobile station using centralized link layer protocol functions of the base station controller and distributed link layer protocol functions of a base station of the first wireless network coupled via the base station interface;

initiate a handover of the mobile station to a second wireless network;

determine a first set of data communication functions to be serviced by the first wireless network after handover, including the centralized link layer protocol functions of the base station controller;

determine a second set of data communication functions to be serviced by the second wireless network after handover, wherein the second set of data communication functions include at least wireless link functions and distributed link layer protocol functions of a base station of the second wireless network;

hand over the mobile station from the first wireless network to the second wireless network; and

service the mobile station after handover using the first set of data communication functions provided by the first wireless network.

12. The base station controller of claim 11, wherein the second set of data communication functions comprises call control functions performed by a base station controller of the second wireless network.

13. The base station controller of claim 12, wherein the base station controller communicatively couples to the base station of the second wireless network via the base station interface and a radio access network and services the data communication there through.

14. The base station controller of claim 11, wherein the first set of data communication functions includes link layer data buffering functions performed by the base station controller.

15. The base station controller of claim 11, wherein the second set of data communication functions includes link layer data buffering functions performed by a base station controller of the second wireless network.

16. The base station controller of claim 11, wherein the second set of data communication functions includes call control functions performed by a base station controller of the second wireless network.

17. The base station controller of claim 16, wherein the call control functions include layer 2/3 call control functions.

18. The base station controller of claim 11, wherein when the mobile station is serviced after handover, the base station controller routes the data communication to a base station controller of the second wireless network.

19. The base station controller of claim 18, wherein when the mobile station is serviced after handover, the base station controller provides link layer data buffering functions.

20. The base station controller of claim 11, wherein at least a portion of a data routing path servicing the data communication remains after handover.

21. A plurality of software instructions stored on a media for execution by a base station controller, the plurality of software instructions comprising:

a set of instructions executed by the base station controller that cause the base station controller to service a data communication for a mobile station using centralized link layer protocol functions of the base station controller and distributed link layer protocol functions of a base station of the first wireless network coupled via the base station interface;

a set of instructions executed by the base station controller that cause the base station controller to initiate a handover of the mobile station to a second wireless network;

a set of instructions executed by the base station controller that cause the base station controller to determine a first set of data communication functions to be serviced by the first wireless network after handover, including the centralized link layer protocol functions of the base station controller;

a set of instructions executed by the base station controller that cause the base station controller to determine a second set of data communication functions to be serviced by the second wireless network after handover, wherein the second set of data communication functions include at least wireless link functions and distributed link layer protocol functions of a base station of the second wireless network;

a set of instructions executed by the base station controller that cause the base station controller to hand over the mobile station from the first wireless network to the second wireless network; and

a set of instructions executed by the base station controller that cause the base station controller to service the mobile station after handover using the first set of data communication functions provided by the first wireless network.