OPTIMIZING TOPOLOGY LEARNING IN A MULTIHOP NETWORK

• US 20080107076A1
• Filed: 11/07/2006
• Published: 05/08/2008
• Est. Priority Date: 11/07/2006
• Status: Active Grant

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ramachandran, Shyamal, Goldberg, Keith J.
• Granted Patent: US 7,742,448 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04W 40/246 Connectivity information discovery

Abstract

In a multihop network having a first type of node, a second type of node and a third type of node, techniques are provided for optimizing topology learning in the multihop network which can reduce the amount of control traffic that occurs due to frequent topology changes. For example, each of the nodes can transmit a node identifier and status information to the first type of node. The status information associated with each node can include a node type and a mobility state of the node. The first type of node can store the node identifier and the status information from each of the nodes. The first type of node can reserve or allocate a channel resource to each of the second type of nodes having a mobile state. The channel resource is used by the second type of node for exchanging topology information with the first type of node.

Claims

1. In a multihop network comprising at least one first type of node and a plurality of nodes comprising at least one of a second type of node and a third type of node, a method comprising:

transmitting a node identifier and status information from each of the nodes to the first type of node, wherein the status information associated with each node comprises;

a node type comprising one of a second type of node and a third type of node, and a mobility state of the node comprising one of a fixed/stationary state or a mobile state;

storing the node identifier and the status information from each of the nodes at the first type of node; and

allocating, at the first type of node, a channel resource to each of the second type of nodes having a mobile state, wherein the channel resource is for exchanging topology information with the first type of node.

2. A method according to claim 1, wherein the status information associated with each node further comprises:

an association type comprising a direct association type or indirect association type, and wherein the method further comprises;

allocating, at the first type of node, a second channel resource to each of the second type of nodes having the mobile state,

wherein the second channel resource is for exchanging topology information with the third type of nodes which are associated with the second type of node, wherein third type of nodes have the indirect association type.

3. A method according to claim 1, further comprising:

determining a first mobility state at each of the second type of nodes and at each of the third type of nodes at a first time.

4. A method according to claim 3, further comprising:

determining a new mobility state at each of the second type of nodes at a second time;

determining, at each of the second type of nodes after the second time, whether the first mobility state of that node has changed with respect to their new mobility state.

5. A method according to claim 4, further comprising:

determining, at each of the second type of nodes which determine that their first mobility state has changed, whether the first mobility state at each of the second type of nodes was mobile or non-mobile.

6. A method according to claim 5, further comprising:

deallocating, at the first type of node, the previously allocated channel resource reserved for ones of the second type of nodes which have experienced a change to a non-mobile mobility state during a period between the first time and the second time.

7. A method according to claim 1, wherein the first type of node comprises a base station.

8. A method according to claim 7, wherein the second type of node comprises a relay station.

9. A method according to claim 8, wherein the status information associated with the relay station comprises:

a relay station node type.

10. A method according to claim 9, wherein the status information associated with the relay station further comprises one of:

a mobile state and a fixed/stationary state.

11. A method according to claim 10, wherein the plurality of nodes further comprise:

at least one mobile relay station, and wherein the mobile relay station has status information associated therewith comprising the relay station node type and the mobile state.

12. A method according to claim 1, wherein the third type of node comprises:

a subscriber station, and wherein the status information associated with the subscriber station comprises a subscriber station node type.

13. A method according to claim 1, wherein the topology information comprises handoff information.

14. A method according to claim 1, wherein the topology information comprises routing information.

15. A method according to claim 1, wherein the topology information comprises link quality information.

16. A method according to claim 1, wherein the topology information comprises measurement reports information.

17. A method according to claim 1, wherein the topology information comprises Quality of Service information.

18. A method according to claim 1, wherein the first type of node comprises a first relay station.

19. A method according to claim 18, wherein the second type of node comprises a second relay station, and further comprising:

a base station, wherein the first relay station is located along a route between the base station and the second relay station such that the second relay station communicates with the base station via the first relay station.

20. In a multihop network comprising at least one first type of node and a plurality of nodes comprising at least one of a second type of node and a third type of node, a method of operating the second type of node within the multihop network comprising:

transmitting a node identifier and status information from each of the nodes to the first type of node, wherein the status information associated with each node comprises;

a node type comprising one of a second type of node and a third type of node, and a mobility state of the node comprising one of a fixed/stationary state or a mobile state; and

receiving a first message from the first type of node at each of the second type of nodes having a mobile state, wherein each first message specifies a channel resource allocated to a particular second type of node by the first type of node for exchanging topology information with the first type of node.

21. A method according to claim 20, wherein the status information associated with each node further comprises:

an association type comprising a direct association type or indirect association type, and wherein the third type of nodes have the indirect association type, and wherein each first message further specifies a second channel resource allocated to a particular second type of node by the first type of node for exchanging other topology information with the third type of nodes which are associated with the particular second type of node.

22. A method according to claim 20, further comprising:

determining a first mobility state at each of the second type of nodes at a first time.

23. A method according to claim 22, further comprising:

determining a new mobility state at each of the second type of nodes at a second time; and

determining, at each of the second type of nodes after the second time, whether the first mobility state of that node has changed with respect to their new mobility state.

24. A method according to claim 23, further comprising:

determining, at each of the second type of nodes which determine that their first mobility state has changed, whether the first mobility state at each of the second type of nodes was mobile or non-mobile.

25. A method according to claim 24, wherein the first type of node de-allocates the previously allocated channel resources reserved for ones of the second type of nodes which have experienced a change to a non-mobile mobility state during a period between the first time and the second time.

26. A method according to claim 20, wherein the topology information comprises at least one of:

handoff information, routing information, link quality information, measurement reports information, and Quality of Service information.

27. In a multihop network comprising at least one first type of node and a plurality of nodes comprising at least one of a second type of node and a third type of node, a method of operating the first type of node within the multihop network comprising:

receiving, at the first type of node, a node identifier and status information from each of the nodes to the first type of node, wherein the status information associated with each node comprises;

a node type comprising one of a second type of node and a third type of node, and a mobility state of the node comprising one of a fixed/stationary state or a mobile state;

storing, at the first type of node, the node identifier and the status information from each of the nodes; and

allocating, at the first type of node, a channel resource to each of the second type of nodes having a mobile state,

wherein the channel resource is for exchanging topology information with the first type of node.

28. A method according to claim 27, wherein the status information associated with each node further comprises:

an association type comprising a direct association type or indirect association type, and wherein the method further comprises;

allocating, at the first type of node, a second channel resource to each of the second type of nodes having the mobile state,

wherein the second channel resource is for exchanging topology information with the third type of nodes which are associated with the second type of node, wherein third type of nodes have the indirect association type.

29. A method according to claim 27, wherein each of the second type of nodes determine whether their mobility state has changed from a mobile state to a non-mobile mobility state after the channel resource has been allocated, and wherein each of the second type of nodes which determine that their first mobility state has changed transmit a second message to the first type of node, wherein the second message comprises an indication that the mobility state of that node has changed from the mobile state to the non-mobile mobility state.

30. A method according to claim 29, further comprising:

de-allocating, at the first type of node responsive to the second message, the previously allocated channel resource reserved for ones of the second type of nodes which have changed from the mobile state to the non-mobile mobility state.

31. A method according to claim 27, wherein the topology information comprises at least one of:

handoff information, routing information, link quality information, measurement reports information, and Quality of Service information.