Wide area network mobility for IP based networks

• US 6,904,025 B1
• Filed: 10/12/1999
• Issued: 06/07/2005
• Est. Priority Date: 10/12/1999
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Sultana, Shabnam, Madour, Lila
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): George, Keith M.
• Application Number:
  US09/416,757
• Time in Patent Office: 2,065 Days
• Field of Search: 370/310.2, 370/328, 370/331, 370/332, 370/333, 370/338, 370/395.52, 455/422, 455/433, 455436-439
• US Class Current: 370/328
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: H04W 76/22 Manipulation of transport tunnels
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A system and method of providing mobility between Internet Protocol (IP) based packet networks is disclosed. The disclosed system and method permits user equipment to roam from one IP based packet network to a second IP based packet network, without any interruption in data communications. Wide area network mobility is achieved through the modification of existing protocols to include additional network gateway addressing information.

Claims

1. A method of keeping a session active and connected with a mobile device while changing data communications networks, from a first data communication network to a second data communication network, comprising the steps of:

receiving all packets, associated with a session, over a first connection in said first data communications network wherein said first connection is handled by a first gateway associated with said first data communications network regardless of whether said mobile device is located within said first or second data communication network;

requesting a second connection with a second data communications network while said mobile device is moving towards the second data communication network;

determining that said mobile device is in said second data communication network;

initiating a transition to said second data communication network by sending a Packet Data Protocol context request towards said first data communication network, said context request including an address of said first gateway provide by said mobile device and if said first gateway address is not present in the context request, retrieving said first gateway address from a Home Location Register (HLR) of said first data communication network;

acquiring an address of a second gateway associated with the second data communications network and assigned to handle said second connection;

establishing a tunnel between said first gateway associated with the first data communications network serving said first connection and said second gateway;

routing said packets associated with said session and received by said first gateway over said established tunnel to said second gateway and over the second connection based on the acquired gateway address to said mobile device.

2. The method of claim 1, wherein an entity in the second data communications network initiates the request for the establishment of said tunnel.

3. The method of claim 2 wherein said second gateway provides network identity associated with said second gateway to said first gateway.

4. The method of claim 2 wherein said second gateway retrieves network identity associated with said first gateway from a centralized database.

5. The method of claim 1, wherein said first gateway in the first data communications network initiates the request for the establishment of said tunnel.

6. The method of claim 5 wherein said first gateway provides network identity associated with said first gateway to said second gateway.

7. The method of claim 5 wherein said first gateway buffers data Intended for said mobile device until said tunnel has been establish with said second gateway.

8. The method of claim 1, wherein mobile device initiates the request for the second connection.

9. The method of claim 8 wherein said mobile device provides the first data communications network with network identity associated with said second gateway.

10. The method of claim 8 wherein said mobile device provides the second data communications network with network identity associated with said first gateway.

11. The method of claim 1 wherein said first gateway is a Gateway General Packet Radio Services Serving Node (GGSN).

12. The method of claim 1 wherein said first data communications network communicates with said second data communications network using Mobile IP protocol.