L2 Tunneling-based Low Latency Single Radio Handoffs

• US 20100054207A1
• Filed: 09/04/2008
• Published: 03/04/2010
• Est. Priority Date: 09/04/2008
• Status: Active Grant

• Current Assignee: Tahoe Research Limited (f/k/a Learndale Limited) (Vector Capital Corporation)
• Original Assignee: Intel Corporation
• Inventors: Gupta, Vivek, Taaghol, Pouya
• Granted Patent: US 8,891,441 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface

Abstract

An example of this invention provides low latency handovers between Mobile WiMAX and 2G/3G/LTE networks with only a single radio transmitting at any given point in time, by establishing L2 tunnel between 3GPP MME and WiMAX ASN for control plane signaling to perform pre-registration, pre-authentication and context transfer to the target network, while UE maintains its connection to the source network, and by setting up bearer path for packet forwarding between Servicing Gateway and WiMAX ASN. An example of this invention uses a virtual eNB to facilitate low latency L2 handoffs to legacy 2G/3G networks with minimum impact to SGSN and MME.

Claims

1. A method for inter-network single radio handover, said method comprising:

exchanging control data between a user equipment and a target radio network through a data link layer tunnel established between a mobility management entity in a core network and said target radio network;

switching a radio from a source radio network to said target radio network; and

receiving forwarded packets sent through a bearer data path established between said core network and said target radio network.

5. A method as recited in claim 1, said method further comprising:

measuring radio parameters in said target radio network by said radio.

6. A method as recited in claim 5, said method further comprising:

receiving a handover preparation command.

7. A method as recited in claim 1, wherein said control data comprises pre-registration communication.

8. A method as recited in claim 1, wherein said control data comprises an attach procedure.

9. A method as recited in claim 1, wherein said core network is a 3GPP evolved packet core.

10. A method as recited in claim 1, wherein said target radio network is one of the following:

WiMAX, E-UTRAN, LTE, or Wi-Fi; and

wherein said source radio network is one of the following;

WiMAX, E-UTRAN, LTE, GERAN, UTRAN, or Wi-Fi.

2. A method for inter-network single radio handover, said method comprising:

establishing an access tunnel, through a source radio network, between a core network and a user equipment connected to said source radio network;

establishing a data link layer tunnel between a mobility management entity in said core network and a target radio network for exchanging control data between said target radio network and said user equipment; and

establishing a bearer data path to forward packets between said core network and said target radio network.

11. A method as recited in claim 2, said method further comprising:

transferring context to said target radio network through said data link layer tunnel.

12. A method as recited in claim 2, said method further comprising:

initiating data forwarding after a handover command is received or issued by said core network.

13. A method as recited in claim 2, said method further comprising:

deciding to handover to said target radio network based on one or more selection criteria.

14. A method as recited in claim 2, wherein said bearer data path is established to a serving gateway in said core network.

15. A method as recited in claim 2, wherein said core network is a 3GPP evolved packet core.

16. A method as recited in claim 2, wherein said target radio network is one of the following:

WiMAX, E-UTRAN, LTE, or Wi-Fi; and

wherein said source radio network is one of the following;

WiMAX, E-UTRAN, LTE, GERAN, UTRAN, or Wi-Fi.

3. A method for inter-network single radio handover, said method comprising:

establishing a data link layer tunnel between a mobility management entity in a core network and a target radio network for exchanging control data between said target radio network and a user equipment connected to a source radio network;

establishing a bearer data path to forward packets between said core network and said target radio network; and

establishing a proxy mobile-IP binding between a packet data network gateway and a network access element for said target radio network.

17. A method as recited in claim 3, said method further comprising:

starting data forwarding after a handover event or HARQ/ARQ retransmissions.

18. A method as recited in claim 3, wherein said control data comprises pre-registration communication.

19. A method as recited in claim 3, said method further comprising:

forwarding data to said user equipment after completion of said user equipment entry in said target radio network.

20. A method as recited in claim 3, wherein said bearer data path is established to a serving gateway in said core network.

21. A method as recited in claim 3, wherein said core network is a 3GPP evolved packet core.

22. A method as recited in claim 3, wherein said target radio network is one of the following:

WiMAX, E-UTRAN, LTE, or Wi-Fi; and

wherein said source radio network is one of the following;

WiMAX, E-UTRAN, LTE, GERAN, UTRAN, or Wi-Fi.

4. A method for inter-network single radio handover, said method comprising:

establishing a data link layer tunnel between a mobility management entity in a core network and a source radio network for exchanging control data between said core network and a user equipment connected to said source radio network;

sending a handover message to said user equipment by a virtual node in said core network; and

establishing a proxy mobile-IP binding between a packet data network gateway and a network access element for a target radio network.

23. A method as recited in claim 4, said method further comprising:

sending an update message to a serving gateway in said core network to update a location of said user equipment.

24. A method as recited in claim 4, wherein said virtual node in said core network is a virtual evolved-node B.

25. A method as recited in claim 4, said method further comprising:

sending a handover command from said mobility management entity to said virtual node.

26. A method as recited in claim 4, wherein said control data comprises an attach procedure.

27. A method as recited in claim 4, said method further comprising:

requesting said target radio network to allocate resources to handover said user equipment.

28. A method as recited in claim 27, wherein said mobility management entity sends said request to allocate said resources to a SGSN.

29. A method as recited in claim 4, wherein said core network is a 3GPP evolved packet core.

30. A method as recited in claim 4, wherein said target radio network is one of the following:

GERAN or UTRAN; and

wherein said source radio network is one of the following;

WiMAX, E-UTRAN, LTE, GERAN, UTRAN, or Wi-Fi.