Optimized scheduling method for delay-sensitive traffic on high speed shared packet data channels
View Patent ↗The present invention supports a scheduling protocol on a wireless communication network to transmit data packets stored in a queue from a user. Two performance metrics are generated and summed to provide a priority. The performance metrics are based on the delay for the data packets stored in the queue and the rate that the data packets can be transmitted on the network. The user with the higher calculated priority for the current time slot has its data packets transmitted.
1. A packet-based wireless communication system comprising:
a scheduler for scheduling transmission of information packets by assigning a priority generated from an algorithm which utilizes at least one performance metric for each data packet in a queue for transmission to a plurality of wireless terminals, said at least one performance metric based in part on an analysis of a time period before one of said packets in the queue will be dropped from the queue; and
a radio network for wireless transmission of information packets to a plurality of wireless terminals, said radio network being connected to the scheduler for sequentially transmitting information in the queue to the wireless terminals according to the assigned priority.
2. The packet-based wireless communication system of claim 1 wherein the at least one performance metric comprises a delay metric computed based on time to expiration of each data packet in a queue for transmission to a plurality of wireless terminals.
3. The packet-based wireless communication system of claim 1 wherein the at least one performance metric comprises a rate metric computed based on the size of an information packet payload.
4. The packet-based wireless communication system of claim 1 wherein the algorithm comprises a first performance metric and a second performance metric.
5. The packet-based wireless communication system of claim 4 wherein the first performance metric comprises a delay metric computed based on the time to expiration of each data packet in a queue for transmission to a plurality of wireless terminals.
6. The packet-based wireless communication system of claim 4 wherein the second performance metric comprises a rate metric computed based on the size of an information packet payload.
7. The packet-based wireless communication system of claim 1 wherein the algorithm adds the value of a first performance metric and second performance metric as part of the priority assignment determination.
8. The packet-based wireless communication system of claim 7 wherein the algorithm establishes a priority based on the sum of the first performance metric and the second performance metric, wherein the first performance metric is a delay metric and the second performance metric is a rate metric.
9. The packet-based wireless communication system of claim 8 wherein:
the delay metric is calculated using the time to expiration of the data packet; and the rate metric is calculated based on the projected size of an information packet payload.
10. A method for assigning a time slot within a time slot cycle in a packet-based communication network comprising the steps of:
scheduling transmission of an information packet from a radio network by assigning a priority to a user of the network generated by an algorithm using each data packet stored for the user, said algorithm using at least one performance metric for each data packet in a queue storage for said user, said performance metric based in part on an analysis of the number of complete packets that can be transmitted from a queue if the user assigned to that queue is selected for transmission; and
controlling said radio network using a radio network controller to transmit said information packet assembled from at least one data packet in said queue storage for said user.
11. The method for assigning a time slot within a time slot cycle in a packet-based communication network of claim 10 , further comprising the step of:
calculating the priority using the sum of a first performance metric and a second performance metric.
12. The method for assigning a time slot within a time slot cycle in a packet-based communication network of claim 11 , further comprising the step of:
generating the first performance metric based on the time to expiration of a data packet stored in the queue for a user.
13. The method for assigning a time slot within a time slot cycle in a packet-based communication network of claim 11 , further comprising the step of:
generating the second performance metric based on the number of data packets stored in the queue for a user that can be transmitted in an assembled information packet.
14. The method for assigning a time slot within a time slot cycle in a packet-based communication network of claim 11 , further comprising the step of:
generating a priority according to an algorithm wherein the first performance metric is a delay metric.
15. The method for assigning a time slot within a time slot cycle in a packet-based communication network of claim 11 , further comprising the step of:
generating a priority according to an algorithm wherein the second performance metric is a rate metric.
16. A method of packet-based wireless communication comprising the steps of:
storing data packets for a user in a queue controlled by a radio network controller; and
assigning a priority for a user to allocate system resources, that includes sequentially transmitting one or more data packets for a user with a highest priority in a current time slot, using a first performance metric and a second performance metric, wherein one of said first or second performance metrics is based in part on an analysis of a time period before one of said packets in the queue will be dropped from the queue.
17. The method of packet-based wireless communication of claim 16 , further comprising the step of:
calculating said first performance metric based on time to expiration of data packets for a user stored in said queue.
18. The method of packet-based wireless communication of claim 16 , further comprising the step of:
calculating said second performance metric based on the number of data packets for a user that can be transmitted in an information packet for a current time slot.
19. The method of packet-based wireless communication of claim 16 , further comprising the steps of:
calculating said first performance metric based on time to expiration of data packets for a user stored in said queue; and
calculating said second performance metric based on the number of data packets for a user that can be transmitted in an information packet for a current time slot.
20. The method of packet-based wireless communication of claim 16 further comprising the step of:
generating said priority according to an algorithm summing the first performance metric and the second performance metric.