Offloading method and device for enhancing mobility

• US 9,258,739 B2
• Filed: 04/28/2011
• Issued: 02/09/2016
• Est. Priority Date: 05/13/2010
• Status: Expired due to Fees

• Current Assignee: ZTE Corporation
• Original Assignee: ZTE Corporation
• Inventors: Tang, Delong
• Primary Examiner(s): Obayanju, Omoniyi
• Application Number:
  US13/575,955
• Publication Number:
  US 20120295624A1
• Time in Patent Office: 1,748 Days
• Field of Search: 455/453, 455/436
• US Class Current: 1/1
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2592 using tunnelling or encapsulation
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 76/12 Setup of transport tunnels
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

The present invention provides an offloading method and device for enhancing mobility, used for solving the technical problem of poor mobility in the current offloading and network construction solution. The present invention discloses that: a Network Address Translating (NAT) gateway is deployed in an upper layer of a Femto Node B; a dedicated tunnel for transmitting the offloading data between the Femto Node B and the NAT gateway is established; the NAT translation of the offloading data message is performed by the NAT gateway and the offloading data is forwarded through the dedicated tunnel according to a continuation relationship; when a User Equipment (UE) performs a handover across two Femto Node B'"'"'s due to mobility, it is only necessary to modify the continuation relationship of the UE, without disconnecting and reconnecting the link of the offloading data stream, thereby improving the system'"'"'s mobility.

Claims

1. An offloading method for enhancing mobility, comprising:

deploying a Network Address Translation (NAT) gateway in an upper layer of a Femto Node B, establishing a dedicated tunnel for transmitting offloading data between the Femto Node B and the NAT gateway, wherein the Femto Node B and the NAT gateway each maintain a respective continuation relationship of transmitting the offloading data for User Equipment (UE) based on the dedicated tunnel; and

the Femto Node B performing the data offloading in a Packet Switched (PS) domain according to an offloading strategy, and forwarding the offloading data through the dedicated tunnel according to the continuation relationship;

the NAT gateway performing NAT translation of an offloading data message, and forwarding the offloading data through the dedicated tunnel according to the continuation relationship;

wherein,

the dedicated tunnel is a fixed dedicated channel established on the basis of a Femto Node B;

the continuation relationship maintained by the Femto Node B is;

a corresponding relationship among an Internet Protocol (IP) address of the UE, a Radio Access Bearer (RAB) of the UE and a subscriber identity of the UE; and

the continuation relationship maintained by the NAT gateway is;

a corresponding relationship among a NAT item, the subscriber identity of the UE and the dedicated tunnel;

wherein the method further comprises;

when a UE performs a Femto Node B handover due to mobility, a source Femto Node B informing, via the subscriber identity of the UE, the NAT gateway to suspend transmitting a downlink offloading data message of the subscriber identity of the UE; and

after the UE'"'"'s access to a target Femto Node B, the target Femto Node B submitting the subscriber identity of the UE to the NAT gateway, and the NAT gateway modifying the continuation relationship associated with the UE to the target Femto Node B according to the subscriber identity.

2. The method as claimed in claim 1, wherein,

the dedicated tunnel is a temporary dedicated tunnel established for a Radio Access Bearer (RAB) of the UE;

the continuation relationship maintained by the Femto Node B is;

a corresponding relationship among a subscriber identity of the UE, a dedicated tunnel and the RAB; and

the continuation relationship maintained by the NAT gateway is;

a corresponding relationship among the subscriber identity of the UE, a dedicated tunnel and a NAT item.

3. The method as claimed in claim 2, wherein the method further comprises:

when a UE performs a Femto Node B handover due to mobility, a source Femto Node B informing, via the subscriber identity of the UE or a tunnel identity list, the NAT gateway to suspend transmitting a downlink offloading data message of the subscriber identity of the UE;

after the UE'"'"'s access to a target Femto Node B, the target Femto Node B establishing a new dedicated tunnel with the NAT gateway, and the NAT gateway modifying the continuation relationship associated with the UE according to the subscriber identity of the UE; and

after the handover is completed, the source Femto Node B and the NAT gateway deleting the dedicated tunnel that has expired.

4. The method as claimed in claim 1, wherein the subscriber identity is one of an International Mobile Subscriber Identity (IMSI) and a Temporary Mobile Subscriber Identity (TMSI);

and

a tunnel protocol adopted by the dedicated tunnel is;

General Packet Radio Service Tunneling Protocol for User Plane (GTPU) protocol, Generic Routing Encapsulation (GRE) protocol, Virtual Private Network (VPN) protocol, or Virtual Local Area Network (VLAN) protocol.

9. The method as claimed in claim 2, wherein the subscriber identity is one of an International Mobile Subscriber Identity (IMSI) and a Temporary Mobile Subscriber Identity (TMSI);

and

a tunnel protocol adopted by the dedicated tunnel is;

General Packet Radio Service Tunneling Protocol for User Plane (GTPU) protocol, Generic Routing Encapsulation (GRE) protocol, Virtual Private Network (VPN) protocol, or Virtual Local Area Network (VLAN) protocol.

10. The method as claimed in claim 3, wherein the subscriber identity is one of an International Mobile Subscriber Identity (IMSI) and a Temporary Mobile Subscriber Identity (TMSI);

and

a tunnel protocol adopted by the dedicated tunnel is;

General Packet Radio Service Tunneling Protocol for User Plane (GTPU) protocol, Generic Routing Encapsulation (GRE) protocol, Virtual Private Network (VPN) protocol, or Virtual Local Area Network (VLAN) protocol.

5. An offloading device for enhancing mobility, comprising:

a dedicated tunnel management module, configured to establish and maintain a dedicated tunnel for transmitting offloading data between a Femto Node B and a NAT gateway, maintain a continuation relationship of transmitting the offloading data for a UE based on the dedicated tunnel, and perform a function of switching continuation relationships in a handover procedure;

an offloading data processing module, at the Femto Node B, configured to perform the data offloading in a Packet Switched (PS) domain according to an offloading strategy, receive and transmit the offloading data through the dedicated tunnel according to the continuation relationship; and

a NAT module, at the NAT gateway, configured to perform NAT translation of an offloading data message, forward the offloading data through the dedicated tunnel according to the continuation relationship;

wherein,

the dedicated tunnel established by the dedicated tunnel management module is a fixed dedicated channel;

the continuation relationship relied upon by the offloading data processing module is;

a corresponding relationship among an Internet Protocol (IP) address of the UE, a Radio Access Bearer (RAB) of the UE and a subscriber identity of the UE; and

the continuation relationship relied upon by the NAT module is;

a corresponding relationship among a NAT item, the subscriber identity of the UE and the dedicated tunnel;

wherein,

when a UE performs a Femto Node B handover due to mobility, the NAT module suspends transmitting a downlink offloading data message of the subscriber identity of the UE; and

after the UE'"'"'s access to a target Femto Node B, the dedicated tunnel management module modifies the continuation relationship of the UE to the target Femto Node B according to the subscriber identity.

6. The device as claimed in claim 5, wherein,

the dedicated tunnel established by the dedicated tunnel management module is a temporary dedicated tunnel established for a Radio Access Bearer (RAB) of the UE;

the continuation relationship relied upon by the offloading data processing module is;

a corresponding relationship among a subscriber identity of the UE, a dedicated tunnel and the RAB; and

the continuation relationship relied upon by the NAT module is;

a corresponding relationship among a NAT item, the subscriber identity of the UE and the dedicated tunnel.

7. The device as claimed in claim 6, wherein,

when a UE performs a Femto Node B handover due to mobility, the NAT module suspends transmitting a downlink offloading data message of the subscriber identity of the UE or a tunnel identifying list;

after the UE'"'"'s access to the target Femto Node B, the dedicated tunnel management module establishes a new dedicated tunnel for the UE, modifies the corresponding continuation relationship according to the subscriber identity of the UE, and deletes the dedicated tunnel that has expired after the handover is completed.

8. The device as claimed in claim 5, wherein the subscriber identity is one of an International Mobile Subscriber Identity (IMSI) and a Temporary Mobile Subscriber Identity (TMSI);

and

a tunnel protocol adopted by the dedicated tunnel is;

GTPU protocol, GRE protocol, VPN protocol, or VLAN protocol.

11. The device as claimed in claim 6, wherein the subscriber identity is one of an International Mobile Subscriber Identity (IMSI) and a Temporary Mobile Subscriber Identity (TMSI);

and

a tunnel protocol adopted by the dedicated tunnel is;

GTPU protocol, GRE protocol, VPN protocol, or VLAN protocol.

12. The device as claimed in claim 7, wherein the subscriber identity is one of an International Mobile Subscriber Identity (IMSI) and a Temporary Mobile Subscriber Identity (TMSI);

and

a tunnel protocol adopted by the dedicated tunnel is;

GTPU protocol, GRE protocol, VPN protocol, or VLAN protocol.