Mobility management in wireless internet protocol networks

• US 7,486,641 B2
• Filed: 05/05/2005
• Issued: 02/03/2009
• Est. Priority Date: 05/22/2000
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Reddy, Joseph Soma, Acampora, Anthony
• Primary Examiner(s): SHARMA, SUJATHA R
• Application Number:
  US11/123,860
• Publication Number:
  US 20050226197A1
• Time in Patent Office: 1,370 Days
• Field of Search: 370/338, 370352-356, 370/401, 370/331, 370/475, 370/349, 370/469, 709/249
• US Class Current: 370/331
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 8/087 for preserving data network PoA address despite hand-offs
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation

Abstract

Handoff of (i) a mobile wirelessly communicating device—a mobile—between (ii) as plurality of stationary base stations within cells within a domain of (iii) a stationary gateway router all within (iv) a communications network based on the Internet Protocol (IP) is without interchange of control and responsive to the mobile, only. The gateway router assigns to the mobile at a time before the handoff IP addresses suitable for the mobile to connect to the gateway router through all the plurality of base stations of the domain. Unilaterally deriving a handoff decision to switch base stations, the mobile directs its wireless communications link to a new base station where signal level registration is performed. Responsive to a link layer trigger at the new base station, the gateway router is informed of the handoff, and both the router and the mobile independently construct the mobile'"'"'s new IP address.

Claims

1. A method for wirelessly communicating based on the Internet Protocol (IP), comprising:

assigning to a gateway router a set of IP addresses to address a mobile through one of a plurality of base stations within a domain associated with the gateway router when an initial communication is established between the domain and the mobile;

monitoring handoffs of the mobile station from one base station to another within the domain to obtain updated information of a serving base station that is currently serving the mobile; and

routing data from the gateway router to the serving base station to address the mobile at one of the set of IP addresses corresponding to the serving base station so that the IP address of the mobile changes each time the mobile hands off to a new serving base station.

2. The method as in claim 1, further comprising:

encapsulating a data packet addressed to the mobile at the gateway router;

routing the encapsulated data packet to the serving base station;

decapsulating the encapsulated data packet at the serving base station; and

delivering the decapsulated data packet from the serving base station to the mobile.

3. The method as in claim 1, further comprising:

encapsulating a data packet addressed to the mobile at the gateway router; and

routing the encapsulated data packet to the mobile via the serving base station so that

decapsulating of the encapsulated data packet occurs at the mobile.

4. The method as in claim 1, further comprising:

assigning to the gateway router a set of global IP addresses to address the base stations associated with the gateway router; and

assigning to at least one more gateway router, which controls IP routing in another set of stationary cellular base stations, a different set of global IP addresses.

5. A method for wirelessly communicating based on the Internet Protocol (IP), comprising:

assigning to a gateway router within a domain a set of IP addresses to address a mobile through one of a plurality of base stations associated with the gateway router when an initial communication is established between the domain and the mobile;

monitoring handoffs of the mobile station from one base station to another within the domain to identify a serving base station as a result of each handoff and the associated IP address for the mobile at the serving base station, wherein the associated IP address is one of the set of IP addresses;

operating the gateway router to change an IP address, previously used for the mobile before the handoff to the serving base station, to the associated IP address;

operating the gateway router to encapsulate a data packet for the mobile with the associated IP address to route the encapsulated data packet to the serving base station which in turn delivers the data packet to the mobile.

6. The method as in claim 5, comprising:

decapsulating the encapsulated data packet for the mobile at the serving base station; and

operating the serving base station to deliver the data packet to the mobile without the associated IP address.

7. The method as in claim 5, comprising:

operating the serving base station to deliver the encapsulated data packet with the new IP address to the mobile without first decapsulating the encapsulated data packet; and

wherein the mobile decapsulates the encapsulated data packet to recover the data packet.

8. A method for wirelessly communicating based on the Internet Protocol (IP), comprising:

assigning to a gateway router within a domain a set of IP addresses to address a mobile through one of a plurality of base stations associated with the gateway router when an initial communication is established between the domain and the mobile;

establishing IP tunneling channels to different base stations associated with different IP addresses within the assigned set of IP addresses;

monitoring handoffs of the mobile station from one base station to another within the domain to identify a serving base station as a result of each handoff and the associated IP address for the mobile at the serving base station, wherein the associated IP address is one of the assigned set of IP addresses;

operating the gateway router to change an IP address previously used for the mobile before the handoff to the associated IP address; and

operating the gateway router to use the associated IP address for the mobile to select one of the established IP tunneling channels, that is assigned with the associated IP address during establishing the IP tunneling channels, to route a data packet for the mobile via the serving base station to the mobile.

9. The method as in claim 8, comprising:

receiving from the mobile a signal which indicates a handoff of the mobile to the serving base station in a manner that is transparent to transport and application layers in the mobile.

10. A gateway router configured to couple a domain to a communication network, comprising:

instructions for carrying out operations comprising;

receiving a set of Internet Protocol (IP) addresses to address a mobile through a base station associated with the gateway router when an initial communication is established between the domain and the mobile;

monitoring handoffs of the mobile from one base station to another within the domain to identify a serving base station as a result of each handoff and an associated IP address for the mobile at the serving base station, wherein the associated IP address is one of the set of IP addresses;

changing an IP address previously used for the mobile before the handoff to the serving base station that is associated with the associated IP address; and

encapsulating a data packet for the mobile with the associated IP address to route the encapsulated data packet to the serving base station which in turn delivers the data packet to the mobile.

11. A mobile device for wirelessly communicating based on the Internet Protocol (IP), comprising:

instructions for carrying out the acts comprising;

receiving a set of IP addresses through which a plurality of base stations associated with a gateway router communicate with the mobile device;

monitoring handoffs from one base station to another within the plurality of base stations to obtain updated information of a serving base station that is currently serving the mobile device; and

receiving packets on one of the set of IP addresses corresponding to the serving base station so that the IP address of the mobile device changes each time the mobile hands off to a new serving base station.