Autonomous transport layer connection setup by a transport layer concentrator

1. A method, performed by a transport layer concentrator, for setting up transport layer connections over which application layer messages are to be sent between first and second wireless communication nodes, the method comprising:

receiving a connection setup request from the first node that indicates network layer addresses for both the concentrator and the second node;

setting up a first transport layer connection to the first node in accordance with the setup request;

based on the network layer addresses indicated by the request, autonomously setting up a second transport layer connection to the second node; and

routing application layer messages between the first and second nodes over the first and second connections.

2. The method of claim 1 , wherein autonomously setting up a second transport layer connection to the second node comprises setting up the second connection on the transport layer concentrator's own initiative, without any request from the second node.

3. The method of claim 1 , wherein routing application layer messages between the first and second nodes over the first and second connections comprises transparently routing application layer messages between the first and second nodes over the first and second connections, wherein transparently routing comprises routing the application layers messages without inspecting or otherwise modifying those messages.

4. The method of claim 1 , wherein autonomously setting up a second transport layer connection to the second node comprises:

inspecting the received connection setup request; and

determining that the connection setup request indicates a network layer address belonging to the second node.

5. The method of claim 1 , wherein autonomously setting up the second transport layer connection to the second node comprises autonomously sending a connection setup request to the second node that indicates a network layer address of that second node.

6. The method of claim 1 , wherein the setup of the second connection is delayed until an application layer message is to be sent over that second connection.

7. The method of claim 6 , wherein the autonomously setting up the second connection is triggered by receiving an application layer message from the first node.

8. The method of claim 7 , wherein the application layer message from the first node is an X2 SETUP REQUEST message.

9. The method of claim 7 , wherein receiving an application layer message from the first node prompts the transport layer concentrator to inspect the connection setup request previously received from the first node in order to determine the network layer address of the second node and set up the second connection to the second node.

10. The method of claim 1 , wherein setting up the first and second connections comprises negotiating one or more logical channels to be employed on those connections and autonomously mapping one or more logical channels on the first connection to one or more logical channels on the second connection based on the network layer addresses indicated by the request from the first node.

11. The method of claim 10 , wherein routing of application layer messages between the first and second nodes over the first and second connections is performed based on the mapping.

12. The method of claim 10 , wherein:

the application layer is a X2 layer;

the transport layer is a Stream Control Transmission Protocol (SCTP) layer; and

the one or more logical channels comprise SCTP streams.

13. The method of claim 1 , wherein one of the first connection and the second connection corresponds to a connection to a relatively higher-level node and the other one of the first connection and the second connection corresponds to a connection to a connection to a lower-level node.

14. The method of claim 13 , wherein the higher-level node is an evolved NodeB (eNB) and the lower-level node is a Home eNB.

15. The method of claim 1 , wherein the connection setup request is a request by the first node for setup of the first transport layer connection between the transport layer concentrator and the first node.

16. The method of claim 15 , wherein the connection setup request is a Stream Control Transmission Protocol (SCTP) INIT chunk.

17. A method, implemented by a first wireless communication node, for setting up transport layer connections over which application layer messages are to be sent to a second wireless communication node, the method comprising:

generating a connection setup request that indicates network layer addresses for both a transport layer concentrator and the second node; and

sending the connection setup request to the transport layer concentrator.

18. A transport layer concentrator for setting up transport layer connections over which application layer messages are to be sent between first and second wireless communication nodes, the transport layer concentrator comprising:

one or more processing circuits configured to function as:

a request controller configured to receive a connection setup request from the first wireless communication node, the connection setup request indicating network layer addresses for both the transport layer concentrator and the second wireless communication node;

a setup controller configured to:

set up a first transport layer connection to the first wireless communication node in accordance with the connection setup request; and

based on the network layer addresses indicated by the connection setup request, autonomously set up a second transport layer connection to the second wireless communication node; and

a routing controller configured to route application layer messages between the first and second wireless communication nodes over the first and second transport layer connections.

19. The transport layer concentrator of claim 18 , wherein the transport layer concentrator is a Stream Control Transmission Protocol (SCTP) concentrator.

20. A first wireless communication node for setting up transport layer connections over which application layer messages are to be sent to a second wireless communication node, the first wireless communication node comprising:

one or more processing circuits configured to function as a request controller configured to:

generate a connection setup request that indicates network layer addresses for both a transport layer concentrator and the second node;

send the connection setup request to the transport layer concentrator.

21. The first wireless communication node of claim 20 , wherein the first wireless communication node is an evolved NodeB (eNB).