Assigning an IP address to a mobile station while roaming

• US 6,374,108 B1
• Filed: 11/30/1999
• Issued: 04/16/2002
• Est. Priority Date: 11/30/1999
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hughes, John, Jakobsen, Ken, Crisler, Kenneth James, Romano, Guy George, Averbuch, Rod
• Primary Examiner(s): Kincaid, Lester G.
• Application Number:
  US09/451,328
• Time in Patent Office: 868 Days
• Field of Search: 455/414, 455/432, 455/433, 455/435, 455/445, 455/466, 455/552, 455/553, 455/556, 455/557, 455/422, 370/331, 370/338, 370/389, 370/400, 370/401, 370/402, 370/252, 702/23, 709/226, 709/239, 713/201, 713/202
• US Class Current: 455/432.1
• CPC Class Codes: H04W 8/00 Network data management

Abstract

A cellular radio communications system comprises: at least one base station for broadcasting radio signals to mobile stations within a cell; a mobile station addressable using IP addresses; and a first controller in the cell of the cellular radio communications system, the first controller being adapted: (i) to receive a request from the mobile station that the cellular radio communication system assign to the mobile station the static IP address previously assigned to the mobile station outside of the cell; (ii) in response to the request from the mobile station, to check with a second controller associated with the location where the mobile station was previously registered that the static IP address has not been assigned to another mobile station; and (iii) to assign the static IP address previously assigned to the mobile station, outside of the cell, to the mobile station for use in the cell, if the static IP address has not been assigned to another mobile station. Alternatively, the first controller may perform the check for availability of the static IP address with a controller associated with the location where the static IP address is registered. The invention also comprises methods of mobile station registration in cellular radio communication systems. The invention enables roaming by a mobile station between cellular systems which are under the control of different Software and Measurement Infrastructures. Mobile stations may be adapted to check one or more timers prior to making the static IP address request.

Claims

1. A cellular radio communications system having at least a first and second radio network having different geographical coverage areas, the cellular radio communication system comprising:

a non-mobile-IP capable mobile station addressable using IP addresses, the mobile station being adapted to roam between the first and second radio network, the first network comprising a home network of the mobile station and the second network comprising a foreign network of the mobile station;

a fast controller associated with the first network; and

a second controller comprising infrastructure equipment associated with die second network, the second controller being adapted upon the mobile station roaming from the first network to the second network;

(i) to receive a context activation request from the mobile station that the cellular radio communication system assign to the mobile station a static IP address previously assigned to the mobile station by the first controller;

(ii) in response to the request from the mobile station, to check with the first controller that the static IP address has not been assigned to another mobile station;

(iii) to assign the static IP address previously assigned to the mobile station by the first controller, to the mobile station for use in the second network, if the static IP address has not been assigned to another mobile station; and

(iv) to perform mobile IP registration with the first controller on behalf of the mobile station.

2. A system in accordance with claim 1, wherein the mobile station comprises a ready timer, the mobile station being adapted:

(i) to check whether the ready timer has timed out, and

(ii) if the ready timer has not timed out, to request assignment of the static IP address.

3. A system in accordance with claim 2, wherein the mobile station is adapted to perform the check whether the ready timer has timed out at the time of first context activation in the second network.

4. A system in accordance with claim 1, wherein the mobile station comprises a stand-by timer, and the mobile station is adapted:

(i) to check whether the stand-by timer of the mobile station has timed out; and

(ii) if the stand-by timer has not timed out, to request assignment of the static IP address.

5. A system in accordance with claim 4, wherein the mobile station is adapted to perform the check whether the stand-by timer has timed out at the time of first context activation in the second network.

6. A system in accordance with claim 1, wherein the second network is an administrative unit of the cellular radio communication system having a different pool of IP addresses than the first network.

7. A system in accordance with claim 1, wherein the first controller is the SwMI data controller of the first network, and the second network is under the control of a different Switching and Management Infrastructure (SwMI) than the first network.

8. A system in accordance with claim 1, wherein the cellular radio communication system is part of a packet switched data network.

9. A system in accordance with claim 1, wherein the second controller is adapted to assign a new IP address to the mobile station from the pool of available IP addresses for the second network if the static IP address previously assigned to the mobile station by the first controller has been assigned to another mobile station.

10. A system in accordance with claim 9, wherein the new IP address is a dynamic IP address.

11. The cellular radio communication system of claim 1 wherein the first controller is a home agent of the mobile station in accordance with mobile internet protocol.

12. The cellular radio communication system of claim 1 wherein the second controller is a foreign agent of the mobile station in accordance with mobile internet protocol.

13. A method of mobile station registration in a cellular radio communication system, the cellular radio communication system comprising a plurality of radio networks having different geographical coverage areas, the method of mobile station registration comprising:

a non-mobile-IP-capable mobile station entering a foreign network of the plurality of networks, the mobile station being addressable using IP addresses;

the mobile station requesting that the cellular radio communication system assign to the mobile station the static IP address previously assigned to the mobile station while in a home network of the plurality of networks; and

a first controller comprising infrastructure equipment associated with the foreign network checking with a second controller associated with the home network that the static IP address has not been assigned to another mobile station, and, if the static IP address has not been assigned to another mobile station, the first controller assigning the static IP address previously assigned to the mobile station, while in the home network, to the mobile station for use while in the foreign network; and

the first controller performing mobile IP registration with the second controller on behalf of the mobile station.

14. A method in accordance with claim 13, wherein the mobile station checks whether a ready timer of the mobile station has timed out, and, if the ready timer has not timed out, then the mobile station requests assignment of the static IP address.

15. A method in accordance with claim 14, wherein the mobile station performs the check whether the ready timer has timed out at the time of first context activation upon entering the foreign network.

16. A method in accordance with claim 13, wherein the mobile station checks whether a stand-by timer of the mobile station has timed out, and, if the stand-by timer has not timed out, then the mobile station requests assignment of the static IP address.

17. A method in accordance with claim 16, wherein the mobile station performs the check whether the stand-by timer of the mobile station has timed out at the time of first context activation upon entering the foreign network.

18. A method in accordance with claim 13, wherein the foreign network is an administrative unit of the cellular radio communication system having a different pool of IP addresses than the home network.

19. A method in accordance with claim 13, wherein the foreign network is under the control of a different Switching and Management Infrastructure (SwMI) than the home network.

20. A method in accordance with claim 13, wherein the cellular radio communication system is part of a packet switched data network.

21. A method in accordance with claim 13, wherein, if the static IP address previously assigned to the mobile station while in the home network has been assigned to another mobile station, then the first controller assigns a new IP address to the mobile station from the pool of available IP addresses in the foreign network.

22. A method in accordance with claim 21, wherein the new IP address is a dynamic IP address.

23. The method of claim 13 wherein the second controller is a home agent of the mobile station in accordance with mobile internet protocol.