Method for selecting an inter-subnet idle hand-off technique
View Patent ↗The present invention provides a method that includes accessing a first identifier associated with an idle mobile unit having a first session with a first subnet and a second identifier associated with a second subnet and determining whether the idle mobile unit has moved from the first subnet to the second subnet based on first portions of the first and second identifiers. The method also includes determining whether the first and second subnets are included in a first plurality of subnets based on second portions of the first and second identifiers and selecting one of a plurality of call session transfer techniques for transferring the first session from the first subnet to the second subnet based on whether the first and second subnets are included in the first plurality of subnets.
1. A method, comprising:
accessing, at an idle mobile unit, a first identifier assigned to identify the idle mobile unit having a first session with a first subnet and a second identifier associated with a second subnet;
determining, at the idle mobile unit, whether the idle mobile unit has moved from the first subnet to the second subnet based on first portions of the first and second identifiers;
requesting, at the idle mobile unit in response to the mobile unit moving from the first subnet to the second subnet, that the first session be transferred from the first subnet to the second subnet when the first and second subnets are included in a first subnet group; and
requesting, at the idle mobile unit, that a second session be established with the second subnet when the first and second subnets are in different subnet groups.
2. The method of claim 1 , wherein accessing the first identifier comprises accessing a Unicast Access Terminal Identifier assigned to identify the mobile unit, and wherein accessing the second identifier comprises accessing a sector identifier associated with the second subnet.
3. The method of claim 1 , comprising determining whether the first subnet and the second subnet are included in the first subnet group in response to determining that the mobile unit has moved from the first subnet to the second subnet.
4. The method of claim 1 , wherein determining whether the idle mobile unit has moved from the first subnet to the second subnet based on the first portions of the first and second identifiers comprises applying a first mask to the first and second identifiers and comparing first masked portions of the first and second identifiers.
5. The method of claim 4 , wherein determining whether the idle mobile unit has moved comprises determining that the idle mobile unit has moved when the first masked portions of the first and second identifiers are different.
6. The method of claim 5 , wherein determining whether the first and second subnets are included in the first subnet group comprises applying a second mask, different than the first mask, to the first and second identifiers and comparing second masked portions of the first and second identifiers.
7. The method of claim 6 , wherein determining whether the first and second subnets are included in the first subnet group comprises determining that the first and second subnets are included in the first subnet group when the second masked portions of the first and second identifiers are the same.
8. The method of claim 7 , comprising determining that the first subnet is included in the first subnet group and the second subnet is included in a second subnet group when the second masked portions of the first and second identifiers are different.
9. The method of claim 8 , comprising determining whether a transition path from the first subnet to the second subnet is known.
10. The method of claim 9 , wherein requesting that the second session be established comprises forming the second session associated with the second subnet in response to determining that the first subnet is included in the first subnet group and the second subnet is included in the second subnet group and in response to determining that the transition path from the second subnet to the first subnet is not known.
11. The method of claim 10 , wherein forming the second session comprises forming the second session with a base station router in the second subnet.
12. The method of claim 10 , wherein forming the second session comprises forming a connection associated with the second session.
13. The method of claim 12 , comprising negotiating transfer of the first session using the connection associated with the second session.
14. The method of claim 1 , comprising providing a request to transfer the first session from the first subnet to the second subnet when the first subnet and a second subnet are included in the first subnet group.
15. The method of claim 14 , wherein providing the request to transfer the first session from the first subnet to the second subnet comprises providing a request including a color code associated with the first subnet.
16. The method of claim 14 , wherein providing the request to transfer the first session from the first subnet to the second subnet comprises providing the request to a base station router in the second subnet.
17. A method, comprising:
requesting, from an idle mobile unit that has roamed from a first base station router in a first subnet included in a first subnet group to a second base station router in a second subnet, that a first session with the first base station router be transferred to the second base station router when the second subnet is included in the first subnet group; and
requesting, from the idle mobile unit, that a second session be established with the second base station router in the second subnet when the second subnet is not included in the first subnet group.
18. The method of claim 17 , comprising negotiating transfer of the first session from the first base station router to the second base station router using a connection associated with the second session.