Scheduling wireless communications
View Patent ↗A system and method is provided for scheduling transmissions from a plurality of services operating over a widely distributed communications network. A headend communications device (such as a cable modem termination system) arbitrates bandwidth among a plurality of cable modems configurable for bi-directional communications. The headend grants a bandwidth region to a specified cable modem or assigns contention regions for a group of cable modems. Each cable modem contains a local scheduler that sends requests for bandwidth according to local policies or rules. Upon receipt of a grant from the headend, the local scheduler selects packets to be transmitted to best serve the needs of the services associated with the cable modem. Accordingly, a service requesting bandwidth may not be the service utilizing the grant corresponding to bandwidth request. Nonetheless, the local scheduler manages bandwidth allocation among its local services such that all requesting services eventually receive bandwidth.
1. A device for providing one or more services in a wireless communications network, comprising:
a plurality of queues associated with a plurality of services; and
a scheduler coupled to the plurality of queues and configured to:
send a request for bandwidth to transmit data related to a requesting service;
receive a grant of a bandwidth region from a remote node responsive to the request;
evaluate needs of a plurality of services by evaluating a current state of priority queues associated with each of the plurality of services, wherein the plurality of services include the requesting service and at least one other service;
schedule packets for the plurality of services based on the evaluation; and
wirelessly transmit the scheduled packets in the granted bandwidth region to the remote node.
2. The device of claim 1 , wherein the scheduler is configured to evaluate the current state of the plurality of queues by calculating a number of packets in at least one queue.
3. The device of claim 1 , wherein the scheduler is configured to evaluate the current state of the plurality of queues by determining an amount of bandwidth required for transmitting packets in at least one queue.
4. The device of claim 1 , wherein the scheduler is configured to evaluate the needs of the plurality of services by evaluating at least one of throughput and latency.
5. The device of claim 1 , wherein the scheduler is configured to schedule packets from a higher priority queue prior to scheduling packets from a lower priority queue.
6. The device of claim 1 , wherein the scheduler is configured to wirelessly transmit a piggyback bandwidth request with the scheduled packets in the granted bandwidth region.
7. The device of claim 6 , wherein the scheduler is configured to append the piggyback bandwidth request to the scheduled packets.
8. The device of claim 7 , wherein the scheduler is configured to append the piggyback bandwidth request to one or more voice packets.
9. The device of claim 6 , wherein the scheduler is configured to transmit the piggyback bandwidth request as a message.
10. The device of claim 6 , wherein the scheduler is configured to transmit the piggyback bandwidth request in a header frame.
11. The device of claim 1 , wherein the scheduler is configured to transmit multiple piggyback bandwidth requests with the scheduled packets in the granted bandwidth region.
12. A cable modem for providing one or more services, comprising:
a plurality of queues associated with a plurality of services; and
a scheduler coupled to the plurality of queues and configured to:
send a request for bandwidth to transmit data related to cable modem termination system;
receive a grant of a bandwidth region from the cable modem termination system responsive to the request;
evaluate needs of a plurality of services by evaluating a current state of priority queues associated with each of the plurality of services, wherein the plurality of services include the requesting service and at least one other service;
schedule packets for the plurality of services based on the evaluation; and
transmit the scheduled packets in the granted bandwidth region to the cable modem termination system.
13. The cable modem of claim 12 , wherein the scheduler is configured to evaluate the current state of the plurality of queues by calculating a number of packets in at least one queue.
14. The cable modem of claim 12 , wherein the scheduler is configured to evaluate the current state of the plurality of queues by determining an amount of bandwidth required for transmitting packets in at least one queue.
15. The cable modem of claim 12 , wherein the scheduler is configured to evaluate the needs of the plurality of services by evaluating at least one of throughput and latency.
16. The cable modem of claim 12 , wherein the scheduler is configured to schedule packets from a higher priority queue prior to scheduling packets from a lower priority queue.
17. The cable modem of claim 12 , wherein the scheduler is configured to wirelessly transmit a piggyback bandwidth request with the scheduled packets in the granted bandwidth region.
18. The cable modem of claim 17 , wherein the scheduler is configured to append the piggyback bandwidth request to the scheduled packets.
19. The cable modem of claim 18 , wherein the scheduler is configured to append the piggyback bandwidth request to one or more voice packets.
20. The cable modem of claim 17 , wherein the scheduler is configured to transmit the piggyback bandwidth request as a message.
21. The cable modem of claim 17 , wherein the scheduler is configured to transmit the piggyback bandwidth request in a header frame.
22. The cable modem of claim 12 , wherein the scheduler is configured transmit multiple piggyback bandwidth requests with the scheduled packets in the granted bandwidth region.