Method for handling roaming of mobile device to restricted area
View Patent ↗As a mobile device moves from one location area to another, the mobile device detects the different location identifiers broadcast by the wireless network(s) in those locations areas. The mobile device stores the location identifier for the last location area in which the mobile device was located. By comparing a received location identifier to the stored location identifier, the mobile device determines if the mobile device has entered a new location area. If so, the mobile device sends a location update request. In one embodiment, if the location update request is for a location area to which access by the mobile device is restricted, the network sends a communication to the mobile device that triggers the mobile device to update a location identifier stored at the mobile device to the location identifier for the restricted location area so that the mobile can update the network after entering/selecting a different location area.
1. A method comprising:
receiving, at a network element from a mobile device, a location update request for a location area to which access by the mobile device is restricted; and
sending, from the network element to the mobile device, in response to the location update request, a communication that triggers the mobile device to update a location identifier stored at the mobile device to the location identifier for the restricted location area.
2. The method of claim 1 , wherein the communication is an identifier for identifying the mobile device.
3. The method of claim 2 , wherein the identifier is a temporary mobile subscriber identifier (TMSI) associated with the restricted location area.
4. The method of claim 3 further comprising:
initiating a security procedure that establishes encryption for information sent to and received from the mobile device before the sending step.
5. The method of claim 4 , wherein the security procedure is a UMTS protocol security procedure.
6. The method of claim 4 , wherein the security procedure is a GSM protocol ciphering procedure.
7. The method of claim 4 , further comprising:
sending a location update reject message to the mobile device, wherein the TMSI is sent before the location update reject message is sent.
8. The method of claim 7 , wherein the location update reject message indicates a cause of the location update reject message is one of the mobile device not being authorized to roam in the restricted location area, and the restricted location area having no available cells with which the mobile device may communicate.
9. A method comprising:
receiving, at a network element from a mobile device, a location update request for a location area to which access by the mobile device is restricted; and
assigning and sending the mobile device a temporary mobile subscriber identifier (TMSI) associated with the restricted location area in response to the location update request, the TMSI being assigned and sent by the network element.
10. The method of claim 9 , further comprising:
initiating a security procedure that establishes encryption for information sent to and received from the mobile device before the sending step, wherein the TMSI is sent to the mobile device after the security procedure is initiated.
11. The method of claim 10 , further comprising:
sending a location update reject message to the mobile device, wherein the TMSI is sent before the location update reject message is sent.
12. The method of claim 10 , wherein the security procedure is a UMTS protocol security procedure.
13. The method of claim 10 , wherein the security procedure is a GSM protocol ciphering procedure.
14. The method of claim 11 , wherein the location update reject message indicates a cause of the location update reject message is one of the mobile device not being authorized to roam in the restricted location area, and the restricted location area having no available cells with which the mobile device may communicate.
15. A method, comprising:
sending, from a mobile device, a location update request for a location area to which access by the mobile device is restricted;
receiving a communication at the mobile device; and
updating a location identifier stored at the mobile device to the location identifier for the restricted location area in response to the received communication.
16. The method of claim 15 , wherein the communication is an identifier for identifying the mobile device.
17. The method of claim 16 , wherein the identifier is a temporary mobile subscriber identifier (TMSI) associated with the restricted location area.
18. The method of claim 15 , wherein the location update request is sent to a mobile switching center (MSC) associated with the restricted location area.