Dynamic forward assignment of internet protocol addresses in wireless networks

• US 20020118656A1
• Filed: 02/27/2001
• Published: 08/29/2002
• Est. Priority Date: 02/27/2001
• Status: Active Grant

• Current Assignee: Telcordia Legacy Inc.
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson), Toshiba Corporation
• Inventors: Zhang, Tao, Agrawal, Prathima, Vakil, Faramak, Kodama, Toshikazu
• Granted Patent: US 6,965,584 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• 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 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method and system for dynamic forward assignment of IP addresses in a wireless network wherein a serving base station requests IP addresses of it neighboring cells. The serving base station then provides the requested IP addresses to the mobile stations it serves based on whether the mobile station will be entering a particular neighboring cell. Immediately upon entering the neighboring cell the mobile station establishes over the air communications with the neighboring cell'"'"'s base station using one of the requested addresses. In another embodiment of the present invention each mobile unit is responsible for attaining IP addresses from the base stations of neighboring cells. Accordingly, the base stations serve as relay points for the IP address requests from the mobile unit to an address server.

Claims

1. A method for assigning internet protocol addresses in a wireless network, said method comprising the steps of:

requesting, by a serving base station, internet protocol addresses from neighboring base stations;

sending, from each requested neighboring base station, at least one internet protocol addresses allocated for use by a mobile to said serving base station; and

sending, by the serving base station, a list of said requested internet protocol addresses allocated to a mobile station; and

assigning one of said internet protocol address included in said sent list to the mobile station.

2. The method of claim 1 further comprising storing said list in a forward address table in said mobile station.

3. The method of claim 2 further comprising the step of initiating, at the mobile station, the processes necessary for completing handoff to the neighboring base station.

4. The method of claim 2 further comprising the step of using said assigned internet protocol address for communication between the mobile station and the neighboring base station.

5. The method of claim 2 wherein said step of assigning an internet protocol address assignment comprises the substep of communicating, by the serving base station, to an appropriate address server and the mobile station an active status of one of said internet protocol addresses as included in said list of said requested internet protocol addresses allocated to the mobile.

6. The method of claim 2 wherein said step of requesting comprises the step of requesting internet protocol addresses only from the set of neighboring base stations with which the mobile station currently has radio contact.

7. The method of claim 6 wherein said step of requesting further comprises the substep of sending the necessary information about the mobile station user for IP-layer authentication to a neighboring base station.

8. The method of claim 5 further wherein addresses in said list are in an inactive state.

9. The method of claim 5 wherein each internet protocol address in said list includes a lifetime timer and further comprises the step of automatically expiring an associated internet protocol address after its lifetime timer times out.

10. The method of claim 9 wherein said internet protocol addresses are based on the internet protocol version six (6).

11. A wireless network comprising:

a plurality of mobile stations each having a forward address table;

a serving base station, said serving base station having a range defining a cell within which said mobile stations communicate over the air with said serving base station;

neighboring base stations, each of said neighboring base stations defining cells which completely surround said serving base station cell and each of said neighboring station connected to each other and said serving base station by a backbone network; and

a plurality of address servers connected to said backbone network and wherein each base station knows the IP address of each of said plurality of address servers that is responsible for assigning IP addresses to each base station'"'"'s neighboring cell.

12.he. The network of claim 11 wherein the backbone network is an internet protocol network.

13. The network of claim 11 wherein said serving base station executes an internet protocol address assignment process comprising the steps of:

requesting, by said serving base station, internet protocol addresses from said neighboring base stations;

sending, to a mobile station served by the serving base station, a list of said requested internet protocol addresses allocated to the mobile; and

assigning one of said internet protocol address included in said sent list to the mobile station.

14.he. The network of claim 11 wherein said forward address table comprises a list of at least one internet protocol addresses associated with a neighboring base station.

16.he. The method of claim 15 further comprising the step of transmitting said assigned internet protocol addresses to said mobile station.

17.he. The method of claim 16 wherein said step of transmitting said assigned internet protocol addresses further comprises the substeps of transmitting said assigned internet protocol addresses to said relaying serving base station and said serving base station relaying said assigned addresses to said mobile station.

18.he. The method of claim 16 further comprising storing said assigned internet protocol addresses in a forward address table in said mobile station.

19.he. The method of claim 18 further comprising the step of initiating, at the mobile station, the processes necessary for completing handoff to the neighboring base station.

20.he. The method of claim 18 further comprising the step of using said assigned internet protocol address for communication between the mobile station and the neighboring base station.

15. A method for assigning internet protocol addresses in a wireless network, said method comprising the steps of:

transmitting an internet protocol address request from a mobile station to a serving base station of the mobile station;

relaying said internet protocol address request to an address server; and

assigning an internet protocol address, at the address server, responsive to said internet protocol address request.