System and method for implementing mobile IP node lossless transition from an idle state to an awake state

• US 7,869,837 B2
• Filed: 12/13/2006
• Issued: 01/11/2011
• Est. Priority Date: 12/13/2006
• Status: Expired due to Fees

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Sairanen, Jussi-Pekka
• Primary Examiner(s): Corsaro, Nick
• Assistant Examiner(s): Choo, Munsoon
• Application Number:
  US11/610,436
• Publication Number:
  US 20080144573A1
• Time in Patent Office: 1,490 Days
• Field of Search: 370/331, 4554121-4122, 455/574, 455/414.1, 455/432.1, 455/13.4, 455/127.1, 455/343.5, 365/228
• US Class Current: 455/574
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A system and method for implementing a “lossless” transition from an idle state to an active or awake state in a mobile station. When a mobile station informs a serving base transceiver station that it is switching to an idle state, a virtual handover is executed, with the mobile station receiving a new Care of Address (CoA). The CoA is taken from an address space that is solely reserved for idle mobile station in a particular access network. The CoA is used to store data packets that are to be transmitted to the mobile station. Once the mobile station reenters an active state, the buffered packets can be forwarded to the mobile station without packet loss.

Claims

1. A method comprising:

receiving a request to assign a Care of Address (CoA) to a mobile station when the mobile station enters an idle state;

responsive to determining that the requested CoA is an address from an idle address space, selecting the requested CoA, and responsive to determining that the requested CoA is not an address from the idle address space, selecting a new CoA;

receiving a data packet intended for the mobile station; and

forwarding the data packet to the selected CoA.

2. The method of claim 1, further comprising, after selecting the selected CoA, notifying an access network foreign agent of the selected CoA.

3. The method of claim 1, wherein the request includes a suggested CoA for the mobile station.

4. The method of claim 3, wherein the suggested CoA is a CoA previously assigned to the mobile station for use during a previous idle state.

5. The method of claim 1, further comprising:

after the data packet is forwarded to the selected CoA, attempting to awaken the mobile station;

buffering the data packet and any subsequent data packets intended for the mobile station;

receiving an indication that the mobile station has entered a live state; and

forwarding the data packet and the subsequent data packets to the mobile station.

6. The method of claim 1, further comprising, after selecting the selected CoA, storing and mapping a combination of the selected CoA and a media access control (MAC) address for the mobile station to a base transceiver station.

7. The method of claim 6, further comprising:

receiving an indication that the mobile station has attempted to obtain access to a network through a different base transceiver station, the indication including a candidate CoA and MAC address;

verifying that the candidate CoA and MAC address match a stored CoA/MAC address combination for the mobile station; and

if the candidate CoA and MAC address match the stored CoA/MAC address combination, updating the mapping of the stored CoA/MAC address combination to correspond to the different base transceiver station.

8. A computer program product, embodied in a computer-readable medium, including computer code for implementing the processes of claim 1.

9. A computer program product, embodied in a computer-readable medium, including computer code for implementing the processes of claim 5.

10. A computer program product, embodied in a computer-readable medium, including computer code for implementing the processes of claim 7.

11. An apparatus, comprising:

a processor; and

a memory unit communicatively connected to the processor and comprising computer-executable instructions that, when executed by the processor, cause the apparatus at least to perform;

receive a request to assign a Care of Address (CoA) to a mobile station when the mobile station enters an idle state;

responsive to determining that the requested CoA is an address from an idle address space, select the requested CoA, and responsive to determining that the requested CoA is not an address from the idle address space, select a new CoA;

receive a data packet intended for the mobile station; and

forward the data packet to the selected CoA.

12. The apparatus of claim 11, wherein the memory unit further comprises computer-executable instructions that, when executed by the processor, cause the apparatus at least to perform:

after selecting the selected CoA, notify an access network foreign agent of the selected CoA.

13. The apparatus of claim 11, wherein the request includes a suggested CoA for the mobile station.

14. The apparatus of claim 13, wherein the suggested CoA is a CoA previously assigned to the mobile station for use during a previous idle state.

15. The apparatus of claim 11, wherein the memory unit further comprises computer-executable instructions that, when executed by the processor, cause the apparatus at least to perform:

after the data packet is forwarded to the selected CoA, attempt to awaken the mobile station;

buffer the data packet and any subsequent data packets intended for the mobile station; and

in response to receiving an indication that the mobile station has entered a live state, forward the data packet and the subsequent data packets to the mobile station.

16. The apparatus of claim 11, wherein the memory unit further comprises computer-executable instructions that, when executed by the processor, cause the apparatus at least to perform:

after selecting the selected CoA, store and map a combination of the selected CoA and a media access control (MAC) address for the mobile station to a base transceiver station used by the mobile station.

17. The apparatus of claim 16, wherein the memory unit further comprises computer-executable instructions that, when executed by the processor, cause the apparatus at least to perform:

in response to receiving an indication that the mobile station has attempted to obtain access to a network through a different base transceiver station, the indication including a candidate CoA and MAC address, verify that the candidate CoA and MAC address match a stored CoA/MAC address combination for the mobile station; and

if the candidate CoA and MAC address match the stored CoA/MAC address combination, update the mapping of the stored CoA/MAC address combination to correspond to the different base transceiver station.

18. A system comprising:

a mobile station configured to operate in an idle state and a live state;

a first base transceiver station at least selectively communicatively connected to the mobile station; and

an access network gateway at least selectively communicatively connected to the mobile station, the access network gateway configured to receive from the first base transceiver station a request to assign a Care of Address (CoA) to the mobile station when the mobile station enters the idle state,

responsive to determining that the requested CoA is an address from an idle address space, select the requested CoA, and responsive to determining that the requested CoA is not an address from the idle address space, select a new CoA,

receive a data packet intended for the mobile station, and

forward the data packet intended for the mobile station to the selected CoA when the mobile station is in the idle state.

19. The system of claim 18, wherein the first base transceiver station is configured to suggest to the access network gateway a candidate CoA for the mobile station.

20. The system of claim 19, wherein the suggested CoA is a CoA previously assigned to the mobile station for use when previously in the idle state.

21. The system of claim 18, wherein the access network gateway is further configured to:

after the data packet is forwarded to the selected CoA, attempt to awaken the mobile station;

buffer the data packet and any subsequent data packets intended for the mobile station; and

in response to the receipt of an indication that the mobile station has entered the live state, forward the data packet and the subsequent data packets to the mobile station.

22. The system of claim 18, wherein the access network gateway is further configured to, after selecting the selected CoA, store and map a combination of the selected CoA and a media access control (MAC) address for the mobile station to the first base transceiver station.

23. The system of claim 22, wherein the access network gateway is further configured to:

receive an indication that the mobile station has attempted to obtain access to a network through a second base transceiver station, the indication including a candidate CoA and MAC address;

verify that the candidate CoA and MAC address match the stored CoA/MAC address combination for the mobile station; and

if the candidate CoA and MAC address match the stored CoA/MAC address combination, update the mapping of the stored CoA/MAC address combination to correspond to the second base transceiver station.

24. A method comprising:

indicating to a first base transceiver station that a mobile station is to enter an idle state;

in response to the indication, receiving from the first base transceiver station a Care of Address (CoA) assigned by an access network gateway, the received CoA corresponding to a requested CoA when the requested CoA is an address from an idle address space, and the received CoA corresponding to a new CoA when the requested CoA is not an address from the idle address space.

25. The method of claim 24, further comprising:

returning to an active state from the idle state; and

receiving from the received CoA data packets that were intended to be transmitted to the mobile station when in the mobile station was in the idle state.

26. The method of claim 24, wherein the indication includes a prior CoA used by the mobile station when previously in an idle state.

27. The method of claim 24, further comprising:

exiting a coverage area for the first base transceiver station;

entering a coverage area for a second base transceiver station;

transmitting to the second base transceiver station an attempt to obtain access to a network, the attempt including the received CoA and a MAC address for the mobile station.

28. A computer program product, embodied in a computer-readable medium, including computer code for implementing the processes of claim 24.

29. A computer program product, embodied in a computer-readable medium, including computer code for implementing the processes of claim 25.

30. A computer program product, embodied in a computer-readable medium, including computer code for implementing the processes of claim 27.

31. An apparatus comprising:

a processor; and

a memory unit communicatively connected to the processor comprising computer-executable instructions that, when executed by the processor, cause the apparatus at least to perform;

indicating indicate to a first base transceiver station that the apparatus is to enter an idle state, and

process a Care of Address (CoA) received from the first base transceiver station, the CoA assigned by an access network gateway in response to the indication, the received CoA corresponding to a requested CoA when the requested CoA is an address from an idle address space, and the received CoA corresponding to a new CoA when the requested CoA is not an address from the idle address space.

32. The apparatus of claim 31, wherein the memory unit further comprises computer-executable instructions that, when executed by the processor, cause the apparatus at least to perform:

return to an active state from the idle state; and

process data packets received from the received CoA, the data packets having been intended to be transmitted to the apparatus when the apparatus was in the idle state.

33. The apparatus of claim 31, wherein the indication includes a prior CoA used by the mobile station when previously in an idle state.

34. The apparatus of claim 31, wherein the memory unit further comprises computer-executable instructions that, when executed by the processor, cause the apparatus at least to perform:

in response to exiting a coverage area for the first base transceiver station and entering a coverage area for a second base transceiver station, transmitt to the second base transceiver station an attempt to obtain access to a network, the attempt including the received CoA and a MAC address for the apparatus.