Method and apparatus for handover of wireless communication between networks

• US 20080008127A1
• Filed: 07/05/2006
• Published: 01/10/2008
• Est. Priority Date: 07/05/2006
• Status: Active Grant

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation), Intel Corporation
• Original Assignee: Infineon Technologies AG
• Inventors: Benkert, Michael, Bienas, Maik, Eckert, Michael, Choi, Hyung-Nam
• Granted Patent: US 7,808,951 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655
• 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

A method is provided for handover of a communication of a mobile communication device between a first radio access network and a second radio access network. The method comprises storing, by at least one of the communication device and an element of the first radio access network, a context of the communication device in the first radio access network, the context being useable to transfer the communication back to the first radio access network after a transferring to the second radio access network; and transferring the communication to the second radio access network.

Claims

1. A method for handover of a communication of a mobile communication device between a first radio access network and a second radio access network, the method comprising:

storing, by at least one of the communication device and an element of the first radio access network, a context of the communication device in the first radio access network, the context being useable to transfer the communication back to the first radio access network after a transferring to the second radio access network; and

transferring the communication to the second radio access network.

2. The method as recited in claim 1 further comprising;

before the transferring, signaling, by the first radio access network, an activity cycle to the communication device, the activity cycle defining times when the communication device can send uplink signals;

after the transferring, switching a radio resource control state of the communication device in the first radio access network from an active state to an idle state, the communication device being pageable while in the idle state by the first radio access network; and

after the transferring, periodically sending, by the communication device an uplink signal to the first radio access network, the uplink signal indicating a status of the communication in the second radio access network.

3. The method as recited in claim 1 further comprising signaling to the first radio network, by the communication device, an identity of a radio cell of the first radio network, the radio cell being identified by the communication device based on a reception quality of the radio cell detected by the communication device.

4. The method as recited in claim 1 further comprising transferring the communication back to the first radio access network using the stored context.

5. The method as recited in claim 4 further comprising signaling to the first radio network, by the communication device, an identity of a radio cell of the first radio network, the radio cell being identified by the communication device based on a reception quality of the radio cell detected by the communication device, and wherein the handing over the communication back to the first radio network is performed using the identity of the radio cell signaled by the communication device.

6. The method as recited in claim 1 wherein the first radio access network is a third generation mobile network.

7. The method as recited in claim 1 wherein the second radio access network is a broadband access network.

8. The method as recited in claim 7 wherein the broadband access network is at least one of a wireless local area network and a Bluetooth network.

9. The method as recited in claim 2 wherein the active state is LTE_Active and the idle state is LTE_Idle.

10. The method as recited in claim 2 wherein the status of the communication in the second radio access network includes at least one of an active status indicating that the communication has been continued in the second radio access network and an end status indicating that the communication has been terminated in the second radio access network.

11. The method as recited in claim 10 further comprising deleting the context when the uplink signal is not received by the first radio access network after a predefined period of time or when the end status is received by the first radio access network.

12. The method as recited in claim 2 further comprising calculating the activity cycle based on a number of other communication devices handed over to the second radio access network.

13. The method as recited in claim 2 further comprising calculating the activity cycle based on the coverage situation in the second radio access network.

14. The method as recited in claim 12 further comprising calculating the activity cycle using the formula

TTI_—

N=(N+M_Offset)mod P_—

HO

where N is a continuous integer, M_Offset is a selected time offset value, and P_HO indicates a selected time period, at least one of M_Offset and P_HO being selected based on the number of other communication devices handed over to the second radio access network.

15. The method as recited in claim 13 further comprising calculating the activity cycle using the formula

TTI_—

N=(N+M_Offset)mod P_—

HO

where N is a continuous integer, M_Offset is a selected time offset value, and P_HO indicates a selected time period, at least one of M_Offset and P_HO being selected based on the number of other communication devices handed over to the second radio access network.

16. The method as recited in claim 2 further comprising reserving, by the first radio access network, defined blocks of uplink resources for uplink signals.

17. The method as recited in claim 16 wherein the defined blocks of uplink resources are resources in a frequency axis and a time axis.

18. The method as recited in claim 16 further comprising determining the defined blocks of uplink resources using a frequency hopping method.

19. The method as recited in claim 16 further comprising signaling, over a broadcast channel, positions of the reserved defined blocks of uplink resources.

20. The method as recited in claim 1 wherein the context includes an identity of the communication device, a current location of the communication device, and a current resource block of the first radio access network allocated to the communication device.

21. The method as recited in claim 20 wherein the current location of the communication device includes a radio cell identity of the first radio access network and the currently allocated resources block includes a frequency bandwidth.

22. A communication device comprising:

a memory to store a context of the communication device in a first radio access network, the context being useable to transfer a communication of the communication device in the first radio access network back to the first radio access network after a transferring to a second radio access network; and

a controller to transfer the communication to the second radio access network.

23. The communication device as recited in claim 22 wherein the controller is configured to:

before the transferring, receive an activity cycle from the first radio access network, the activity cycle defining times when the communication device can send uplink signals;

after the transferring, switch a radio resource control state of the communication device in the first radio access network from an active state to an idle state, the communication device being pageable in the idle state by the first radio access network; and

after the transferring, periodically send an uplink signal to the first radio access network, the uplink signal indicating a status of the communication in the second radio access network.

24. The communication device as recited in claim 22 wherein the controller is configured to:

identify a radio cell of the first radio network based on a detected reception quality of the radio cell; and

signal to the first radio network an identity of the radio cell.

25. The communication device as recited in claim 22 wherein the controller is configured to transfer the communication back to the first radio access network using the stored context.

26. The communication device as recited in claim 22 wherein the first radio access network is a third generation mobile network.

27. The communication device as recited in claim 22 wherein the second radio access network is a broadband access network.

28. A radio access network comprising:

a memory to store a context of a communication device in the radio access network, the context being useable to transfer a communication of the communication device in the radio access network back to the radio access network after a transferring to a second radio access network; and

a controller to transfer the communication to the second radio access network.

29. The radio access network as recited in claim 28 wherein the controller is configured to:

before the transferring, send an activity cycle to the communication device, the activity cycle defining times when the communication device can send an uplink signal;

after the transferring, switch a radio resource control state of the communication device in the radio access network from an active state to an idle state, the communication device being pageable in the idle state by the radio access network; and

after the transferring, periodically receive an uplink signal indicating a status of the communication in the second radio access network.

30. The radio access network as recited in claim 28 wherein the controller is configured to receive from the communication device an identity of a radio cell of the radio network, radio cell being identified by the communication device based on a reception quality of the radio cell detected by the communication device.

31. The radio access network as recited in claim 28 wherein the controller is configured to transfer the communication back to the radio access network using the stored context.

32. The radio access network as recited in claim 28 wherein the second radio access network is a fixed broadband access network.