Downstream channel change technique implemented in an access network

• US 20060251097A1
• Filed: 07/10/2006
• Published: 11/09/2006
• Est. Priority Date: 10/13/1999
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Lu, Yong, Chapman, John T., Daruwalla, Feisal Y., Crocker, Daniel W., Zang, Joanna Qun
• Granted Patent: US 7,672,230 B2
• Time in Patent Office: Days
• US Class Current: 370/431
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18

Abstract

A dynamic channel change technique is disclosed which may be implemented between nodes and a Head End of an access network. Initially a network device may communicate with the Head End via a first downstream channel and a first upstream channel. When the network device receives a dynamic channel change request which includes instructions for the network device to switch to a second downstream channel, the network device may respond by switching from the first downstream channel to the second downstream channel. Thereafter, the network device may communicate with the Head End via the second downstream channel and first upstream channel. Further, according to a specific embodiment, the dynamic channel change request may also include an upstream channel change request for causing the network device to switch from a first upstream channel to a second upstream channel.

Claims

1. A method for facilitating communications between a network node and a Head End of an access network, the access network including a plurality of nodes which communicate with the Head End via at least one upstream channel and at least one downstream channel, the access network including a first node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the access network further including a second node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the at least one downstream channel including a first downstream channel and a second downstream channel, wherein the first downstream channel is associated with a first channel identifier, and the second downstream channel is associated with a second channel identifier, the at least one upstream channel including a first upstream channel associated with a third channel identifier, wherein the third channel identifier is different from the first channel identifier and second channel identifier, the method comprising:

communicating between the Head End and the first and second nodes via the first downstream channel;

receiving, at the first node, a first communication from the Head End via the first downstream channel, said first communication including a request to perform a dynamic channel change operation, said dynamic channel change (DCC) request including a request to perform a downstream channel change operation to cause the first node to switch from the first downstream channel to the second downstream channel;

implementing, at the first node, the downstream channel change operation in response to the dynamic channel change request;

determining whether data transmitted from the Head End is successfully received at the first node via the second downstream channel;

communicating between the Head End and the first node via the second downstream channel in response to a determination that data transmitted from the Head End can be successfully received at the first node via the second downstream channel; and

communicating between the Head End and the second node via the first downstream channel after successful completion of the downstream channel change operation at the first node; and

switching, at the first node, from the second downstream channel to the first downstream channel in response to a determination that data transmitted at the Head End can not be successfully received at the first node via the second downstream channel.

2. The method of claim 1 wherein the first downstream channel has associated therewith a first frequency, and wherein the second downstream channel has associated therewith a second frequency, the method further comprising:

maintaining the first and second frequencies associated with the first and second downstream channels during the implementing of the downstream channel change operation at the first node.

3. The method of claim 1 further comprising:

performing a load balancing operation which includes transmitting the dynamic channel change request to the first node in order to cause the first node to switch from the first downstream channel to the second downstream channel.

4. The method of claim 1 wherein implementing the dynamic channel change operation comprises:

switching from the first downstream channel to the second downstream channel to receive communications from the Head End at the first node via the second downstream channel.

5. The method of claim 1 further comprising:

communicating, at the first node, with the Head End using data received on the first downstream channel prior to performing the dynamic channel change operation.

6. The method of claim 4 wherein implementing the dynamic channel change operation further comprises:

determining whether said second downstream channel is currently being used for receiving communications from the Head End.

7. The method of claim 4 further comprising transmitting a dynamic channel change response to the Head End in response to receiving the dynamic channel change request.

8. The method of claim 1 wherein said access network is a wireless network.

9. The method of claim 1 wherein said access network is a cable network, said plurality of nodes are cable modems, and wherein said Head End comprises a Cable Modem Termination System (CMTS).

10. The method of claim 1 further comprising:

receiving a request from the Head End to switch from the first upstream channel to a second upstream channel; and

switching to said second upstream channel and said second downstream channel at substantially the same time.

11. The method of claim 10 further comprising:

switching from the first upstream channel to a second upstream channel for transmitting data to the Head End; and

switching from the first downstream channel to the second downstream channel for receiving data from the Head End.

12. The method of claim 10 wherein the switching of the upstream and downstream channels results in a switching between a first domain and a second domain of the access network.

13. The method of claim 12 further comprising initiating a domain registration procedure after successfully switching the upstream and downstream channels.

14. The method of claim 13 further comprising initiating a ranging procedure after successfully switching the upstream and downstream channels.

15. The method of claim 10 wherein the first and second downstream channels are not in synchronization.

16. The method of claim 1 wherein communication between the Head End and the first and second nodes is implemented using a DOCSIS protocol.

17. The method of claim 1 wherein the downstream channel change is implemented at the first node without rebooting or re-initializing the first node.

18. A system for facilitating communications between a network node and a Head End of an access network, the access network including a plurality of nodes which communicate with the Head End via at least one upstream channel and at least one downstream channel, the access network including a first node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the access network further including a second node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the at least one downstream channel including a first downstream channel and a second downstream channel, wherein the first downstream channel is associated with a first channel identifier, and the second downstream channel is associated with a second channel identifier, the at least one upstream channel including a first upstream channel associated with a third channel identifier, wherein the third channel identifier is different from the first channel identifier and second channel identifier, the system comprising:

at least one processor;

at least one interface configured or designed to provide a communication link to at least one other network device in the data network; and

memory;

the system being operable to;

communicate between the Head End and the first and second nodes via the first downstream channel;

receive, at the first node, a first communication from the Head End via the first downstream channel, said first communication including a request to perform a dynamic channel change operation, said dynamic channel change (DCC) request including a request to perform a downstream channel change operation to cause the first node to switch from the first downstream channel to the second downstream channel;

implement, at the first node, the downstream channel change operation in response to the dynamic channel change request;

determine whether data transmitted from the Head End is successfully received at the first node via the second downstream channel;

communicate between the Head End and the first node via the second downstream channel in response to a determination that data transmitted from the Head End can be successfully received at the first node via the second downstream channel; and

communicate between the Head End and the second node via the first downstream channel after successful completion of the downstream channel change operation at the first node; and

switch, at the first node, from the second downstream channel to the first downstream channel in response to a determination that data transmitted at the Head End can not be successfully received at the first node via the second downstream channel.

19. The system of claim 18 wherein the first downstream channel has associated therewith a first frequency, and wherein the second downstream channel has associated therewith a second frequency, the system being further operable to:

maintain the first and second frequencies associated with the first and second downstream channels during the implementing of the downstream channel change operation at the first node.

20. The system of claim 18 being further operable to:

perform a load balancing operation which includes transmitting the dynamic channel change request to the first node in order to cause the first node to switch from the first downstream channel to the second downstream channel.

21. The system of claim 18 being further operable to:

switch from the first downstream channel to the second downstream channel to receive communications from the Head End at the first node via the second downstream channel.

22. The system of claim 18 being further operable to:

communicate, at the first node, with the Head End using data received on the first downstream channel prior to performing the dynamic channel change operation.

23. The system of claim 21 being further operable to:

determine whether said second downstream channel is currently being used for receiving communications from the Head End.

24. The system of claim 21 being further operable to:

transmit a dynamic channel change response to the Head End in response to receive the dynamic channel change request.

25. The system of claim 18 wherein said access network is a wireless network.

26. The system of claim 18 wherein said access network is a cable network, said plurality of nodes are cable modems, and wherein said Head End comprises a Cable Modem Termination System (CMTS).

27. The system of claim 18 being further operable to:

receive a request from the Head End to switch from the first upstream channel to a second upstream channel; and

switch to said second upstream channel and said second downstream channel at substantially the same time.

28. The system of claim 27 being further operable to:

switch from the first upstream channel to a second upstream channel for transmitting data to the Head End; and

switch from the first downstream channel to the second downstream channel for receiving data from the Head End.

29. The system of claim 27 wherein the switching of the upstream and downstream channels results in a switching between a first domain and a second domain of the access network.

30. The system of claim 29 being further operable to:

initiate a domain registration procedure after successfully switching the upstream and downstream channels.

31. The system of claim 30 being further operable to:

initiate a ranging procedure after successfully switching the upstream and downstream channels.

32. The system of claim 27 wherein the first and second downstream channels are not in synchronization.

33. The method of claim 18 wherein the downstream channel change is implemented at the first node without rebooting or re-initializing the first node.

34. The system of claim 18 wherein communication between the Head End and the first and second nodes is implemented using a DOCSIS protocol.

35. A method for facilitating communications between a network node and a Head End of an access network, the access network including a plurality of nodes which communicate with the Head End via at least one upstream channel and at least one downstream channel, the access network including a first node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the access network further including a second node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the at least one downstream channel including a first downstream channel and a second downstream channel, wherein the first downstream channel is associated with a first channel identifier, and the second downstream channel is associated with a second channel identifier, the at least one upstream channel including a first upstream channel associated with a third channel identifier, wherein the third channel identifier is different from the first channel identifier and second channel identifier, the method comprising:

communicating between the Head End and the first and second nodes via the first downstream channel;

transmitting a dynamic channel change request, said dynamic channel change request including a request to perform a downstream channel change operation in order to cause the first node to switch from the first downstream channel to the second downstream channel;

communicating between the Head End and the first node via the second downstream channel after successful completion of the downstream channel change operation at the first node; and

communicating between the Head End and the second node via the first downstream channel after successful completion of the downstream channel change operation at the first node.

36. The method of claim 35, wherein the method further comprises:

determining whether data transmitted at the Head End is successfully received on the second downstream channel; and

switching from the second downstream channel to the first downstream channel in response to a determination that data transmitted at the Head End can not be successfully received on the second downstream channel.

37. The method of claim 35 wherein communication between the Head End and the first and second nodes is implemented using a DOCSIS protocol.

38. The method of claim 35 wherein the downstream channel change is implemented at the first node without rebooting or re-initializing the first node.

39. A system for facilitating communications between a network node and a Head End of an access network, the access network including a plurality of nodes which communicate with the Head End via at least one upstream channel and at least one downstream channel, the access network including a first node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the access network further including a second node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the at least one downstream channel including a first downstream channel and a second downstream channel, wherein the first downstream channel is associated with a first channel identifier, and the second downstream channel is associated with a second channel identifier, the at least one upstream channel including a first upstream channel associated with a third channel identifier, wherein the third channel identifier is different from the first channel identifier and second channel identifier, the system comprising:

at least one processor;

at least one interface configured or designed to provide a communication link to at least one other network device in the data network; and

memory;

the system being operable to;

communicate between the Head End and the first and second nodes via the first downstream channel;

transmit a dynamic channel change request, said dynamic channel change request including a request to perform a downstream channel change operation in order to cause the first node to switch from the first downstream channel to the second downstream channel;

communicate between the Head End and the first node via the second downstream channel after successful completion of the downstream channel change operation at the first node; and

communicate between the Head End and the second node via the first downstream channel after successful completion of the downstream channel change operation at the first node.

40. The system of claim 39 being further operable to:

determine whether data transmitted at the Head End is successfully received on the second downstream channel; and

switch from the second downstream channel to the first downstream channel in response to a determination that data transmitted at the Head End can not be successfully received on the second downstream channel.

41. The system of claim 39 wherein communication between the Head End and the first and second nodes is implemented using a DOCSIS protocol.

42. The system of claim 39 wherein the downstream channel change is implemented at the first node without rebooting or re-initializing the first node.

43. A system for facilitating communications between a network node and a Head End of an access network, the access network including a plurality of nodes which communicate with the Head End via at least one upstream channel and at least one downstream channel, the access network including a first node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the access network further including a second node adapted to communicate with the Head End via at least one downstream channel and at least one upstream channel, the at least one downstream channel including a first downstream channel and a second downstream channel, wherein the first downstream channel is associated with a first channel identifier, and the second downstream channel is associated with a second channel identifier, the at least one upstream channel including a first upstream channel associated with a third channel identifier, wherein the third channel identifier is different from the first channel identifier and second channel identifier, the system comprising:

means for communicating between the Head End and the first and second nodes via the first downstream channel;

means for receiving, at the first node, a first communication from the Head End via the first downstream channel, said first communication including a request to perform a dynamic channel change operation, said dynamic channel change (DCC) request including a request to perform a downstream channel change operation to cause the first node to switch from the first downstream channel to the second downstream channel;

means for implementing, at the first node, the downstream channel change operation in response to the dynamic channel change request;

determining whether data transmitted from the Head End is successfully received at the first node via the second downstream channel;

means for communicating between the Head End and the first node via the second downstream channel in response to a determination that data transmitted from the Head End can be successfully received at the first node via the second downstream channel; and

means for communicating between the Head End and the second node via the first downstream channel after successful completion of the downstream channel change operation at the first node; and

means for switching, at the first node, from the second downstream channel to the first downstream channel in response to a determination that data transmitted at the Head End can not be successfully received at the first node via the second downstream channel.