Systems and methods for selecting serving gateways to service user equipment

1. A method for selecting a serving gateway to service user equipment in communication with a network, comprising:

receiving a message from a base transceiver station including a list of tracking areas handled by the base transceiver station;

performing a domain name system query for at least one tracking area in the list of tracking areas to retrieve and store information indicating a serving gateway serving the at least one tracking area;

receiving an attach request from the base transceiver station identifying the user equipment and a tracking area from which the user equipment is connected to the network;

retrieving the stored information indicating the serving gateway serving the at least one tracking area to identify a serving gateway to service the user equipment based on the tracking area from which the user equipment is connected to the network; and

sending a message identifying the identified serving gateway to the base transceiver station.

2. The method of claim 1 , wherein the message from the base transceiver station including the list of tracking areas includes an S1 setup message.

3. The method of claim 1 , wherein the attach request includes an S1 initial user equipment message.

4. The method of claim 1 , further comprising storing the information indicating the serving gateway serving the at least one tracking area as at least part of a table of sets of tracking area identities and at least one associated serving gateway.

5. The method of claim 4 , wherein, for at least some tracking area identities, there is one and only one associated serving gateway.

6. The method of claim 4 , wherein at least some serving gateways are associated with more than one tracking area identifier.

7. The method of claim 1 , wherein the base transceiver station includes an evolved nodeB.

8. The method of claim 1 , further comprising periodically performing the domain name system query for the at least one tracking area in the list of tracking areas to periodically update the information indicating a serving gateway serving the at least one tracking area.

9. The method of claim 1 , wherein performing the domain name system query for the at least one tracking area includes performing the domain name system query using a tracking area identity fully qualified domain name associated with the at least one tracking area.

10. A mobility management entity in a communication network comprising:

a memory;

a first interface which is configured to receive a message from a base transceiver station including a list of tracking areas handled by the base transceiver station, and receive an attach request from the base transceiver station identifying user equipment and a tracking area from which the user equipment is connected to the network;

a second interface which is configured to perform a domain name system query for at least one tracking area in the list of tracking areas to receive information indicating a serving gateway serving the at least one tracking area;

the mobility management entity configured to store the received information indicating the serving gateway serving the at least one tracking area in the memory; and retrieve the information indicating the serving gateway serving the at least one tracking area stored in the memory to identify a serving gateway to service the user equipment based on the tracking area from which the user equipment is connected to the network; and

the first interface further configured to send a message identifying the identified serving gateway to the base transceiver station.

11. The mobility management entity of claim 10 , wherein the message from the base transceiver station including the list of tracking areas includes an S1 setup message.

12. The mobility management entity of claim 10 , wherein the attach request includes an S1 initial user equipment message.

13. The mobility management entity of claim 10 , the mobility management entity further configured to store the information indicating the serving gateway serving the at least one tracking area in the memory as at least part of a table of sets of tracking area identities and at least one associated serving gateway.

14. The mobility management entity of claim 13 , wherein, for at least some tracking area identities, there is one and only one associated serving gateway.

15. The mobility management entity of claim 13 , wherein at least some serving gateways are associated with more than one tracking area identifier.

16. The mobility management entity of claim 10 , further configured to periodically perform the domain name system query for the at least one tracking area in the list of tracking areas to periodically update the information indicating a serving gateway serving the at least one tracking area.

17. The mobility management entity of claim 10 , further configured to perform the domain name system query for the at least one tracking area using a tracking area identity fully qualified domain name associated with the at least one tracking area.