L2 tunneling-based low latency single radio handoffs
View Patent ↗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.
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 directly between a mobility management entity in a core network and an access services network of said target radio network, the core network comprising a source radio network, and the target radio network being different from the core network and from the source radio network;
switching a radio from the source radio network to said target radio network; and
receiving forwarded packets sent through a bearer data path established directly between a serving gateway of said core network and the access services network of said target radio network.
2. A method for inter-network single-radio handover, said method comprising:
establishing a data link layer tunnel directly between a mobility management entity in a core network and an access services network of a target radio network for exchanging control data between said target radio network and user equipment connected to the core network through a source radio network, the core network comprising the source radio network, and the target radio network being different from the core network and from the source radio network; and
establishing a bearer data path to forward packets directly between a serving gateway of said core network and the access services network of said target radio network.
3. A method for inter-network single-radio handover, said method comprising:
establishing a data link layer tunnel directly between a mobility management entity in a core network and an access services network of a target radio network for exchanging control data between said target radio network and a user equipment connected to the core network through a source radio network, the core network comprising the source radio network, and the target radio network being different from the core network and from the source radio network;
establishing a bearer data path to forward packets directly between a serving gateway of said core network and the access services network of said target radio network; and
establishing a proxy mobile internet protocol (mobile-IP) binding between a packet data network gateway and a network access element for said target radio network.
4. A method for inter-network single-radio handover, said method comprising:
establishing a data link layer tunnel directly between a mobility management entity in a core network and an access services network of a source radio network for exchanging control data between said core network and a user equipment connected to said source radio network, the core network comprising a target radio network, and the source radio network being different from the core network and from the target radio network;
establishing a bearer data path to forward packets directly between a serving gateway of said core network and the access services network of the target radio network
sending a handover message to said user equipment by a virtual node in said core network; and
establishing a proxy mobile internet protocol (mobile-IP) binding between a packet data network gateway and a network access element for the target radio network.
5. The method as recited in claim 1 , said method further comprising: measuring radio parameters in said target radio network by said radio.
6. The method as recited in claim 5 , said method further comprising: receiving a handover preparation command.
7. The method as recited in claim 1 , wherein said control data comprises pre-registration communication.
8. The method as recited in claim 1 , wherein said control data comprises an attach procedure.
9. The method as recited in claim 1 , wherein said core network is a Third Generation Partnership Project (3GPP) evolved packet core.
10. The method as recited in claim 1 , wherein said target radio network is one of the following: Worldwide Interoperability for Microwave Access (WiMAX), evolved-universal mobile telecommunication system (UMTS) terrestrial radio access network (E-UTRAN), Long-Term Evolution (LTE), or Wi-Fi; and
wherein said source radio network is one of the following: WiMAX, E-UTRAN, LTE, Global System for Mobile Communications (GSM) Enhanced Data rates for GSM Evolution (EDGE) Radio Access Network (GERAN), universal mobile telecommunication system (UMTS) terrestrial radio access network (UTRAN), or Wi-Fi.
11. The method as recited in claim 2 , said method further comprising: transferring context to said target radio network through said data link layer tunnel.
12. The 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. The 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. The method as recited in claim 2 , wherein said core network is a Third Generation Partnership Project (3GPP) evolved packet core.
15. The method as recited in claim 2 , wherein said target radio network is one of the following: Worldwide Interoperability for Microwave Access (WiMAX), evolved-universal mobile telecommunication system (UMTS) terrestrial radio access network (E-UTRAN), Long-Term Evolution (LTE), or Wi-Fi; and
wherein said source radio network is one of the following: WiMAX, E-UTRAN, LTE, Global System for Mobile Communications (GSM) Enhanced Data rates for GSM Evolution (EDGE) Radio Access Network (GERAN), universal mobile telecommunication system (UMTS) terrestrial radio access network (UTRAN), or Wi-Fi.
16. The method as recited in claim 3 , said method further comprising: starting data forwarding after a handover event or hybrid automatic repeat request/automatic repeat request (HARQ/ARQ) retransmissions.
17. The method as recited in claim 3 , wherein said control data comprises pre-registration communication.
18. The 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.
19. The method as recited in claim 3 , wherein said core network is a Third Generation Partnership Project (3GPP) evolved packet core.
20. The method as recited in claim 3 , wherein said target radio network is one of the following: Worldwide Interoperability for Microwave Access (WiMAX), evolved-universal mobile telecommunication system (UMTS) terrestrial radio access network (E-UTRAN), Long-Term Evolution (LTE), or Wi-Fi; and
wherein said source radio network is one of the following: WiMAX, E-UTRAN, LTE, Global System for Mobile Communications (GSM) Enhanced Data rates for GSM Evolution (EDGE) Radio Access Network (GERAN), universal mobile telecommunication system (UMTS) terrestrial radio access network (UTRAN), or Wi-Fi.
21. The method as recited in claim 4 , said method further comprising: sending an update message to the serving gateway in said core network to update a location of said user equipment.
22. The method as recited in claim 4 , wherein said virtual node in said core network is a virtual evolved-node B (eNB).
23. The method as recited in claim 4 , said method further comprising: sending a handover command from said mobility management entity to said virtual node.
24. The method as recited in claim 4 , wherein said control data comprises an attach procedure.
25. The method as recited in claim 4 , said method further comprising: requesting said target radio network to allocate resources to handover said user equipment.
26. The method as recited in claim 25 , wherein said mobility management entity sends a request to allocate said resources to a Serving General packet radio service (GPRS) Support Node (SGSN).
27. The method as recited in claim 4 , wherein said core network is a Third Generation Partnership Project (3GPP) evolved packet core.
28. The method as recited in claim 4 , wherein said target radio network is one of the following: Global System for Mobile Communications (GSM) Enhanced Data rates for GSM Evolution (EDGE) Radio Access Network (GERAN)—or—universal mobile telecommunication system (UMTS) terrestrial radio access network (UTRAN); and
wherein said source radio network is one of the following: Worldwide Interoperability for Microwave Access (WiMAX), evolved-universal mobile telecommunication system (UMTS) terrestrial radio access network (E-UTRAN), Long-Term Evolution (LTE) GERAN, UTRAN, or Wi-Fi.