Optimized scheduling method for delay-sensitive traffic on high speed shared packet data channels

Abstract

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.

What is claimed is: 
     
         1 . A radio network controller for a packet-based communication system, the radio network controller comprising:
 a scheduler configured to schedule transmission of information packets by assigning a priority generated from an algorithm which uses at least one performance metric for each data packet in a queue for transmission to a plurality of terminals, said at least one performance metric based at least 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 interface configured to provide information packets to at least one transmitter for sequential transmission of the information packets in the queue to the terminals according to the assigned priority.   
     
     
         2 . The radio network controller of  claim 1 , wherein the at least one performance metric comprises a delay metric computed based on time to expiration of the data packet. 
     
     
         3 . The radio network controller of  claim 1 , wherein the at least one performance metric comprises a rate metric computed based the size of the information packet payload. 
     
     
         4 . The radio network controller of  claim 1 , wherein the algorithm comprises a first performance metric and a second performance metric. 
     
     
         5 . The radio network controller of  claim 4 , wherein the first performance metric comprises a delay metric computed based on the time to expiration of the data packet. 
     
     
         6 . The radio network controller of  claim 4 , wherein the second performance metric comprises a rate metric computed based on the size of the information packet payload. 
     
     
         7 . The radio network controller 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 radio network controller 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 radio network controller 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 the information packet payload.   
     
     
         10 . The radio network controller of  claim 1 , wherein the at least one performance metric is exponentially related to a time of expiration of a packet. 
     
     
         11 . The radio network controller of  claim 1 , wherein the radio network interface is configured to provide the information packets to a radio network that comprises the at least one transmitter. 
     
     
         12 . A scheduler for assigning a time slot within a time slot cycle in a packet-based communication network, the scheduler being configured to schedule transmission of an information packet by assigning a priority to a user of the network, the priority being generated by an algorithm using at least one performance metric for each packet stored in a queue for the user, the performance metric being based at least in part on an analysis of a number of complete packets that can be transmitted from a queue if the user assigned to that queue is selected for transmission. 
     
     
         13 . The scheduler of  claim 12 , wherein the scheduler is configured to calculate the priority using the sum of a first performance metric and a second performance metric. 
     
     
         14 . The scheduler of  claim 13 , wherein the scheduler is configured to generate the first performance metric based on the time to expiration of a data packet stored in the queue for a user. 
     
     
         15 . The scheduler of  claim 13 , wherein the scheduler is configured to generate 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. 
     
     
         16 . The scheduler of  claim 13 , wherein the scheduler is configured to generate a priority according to an algorithm wherein the first performance metric is a delay metric. 
     
     
         17 . The scheduler of  claim 13 , wherein the scheduler is configured to generate a priority according to an algorithm wherein the second performance metric is a rate metric. 
     
     
         18 . The scheduler of  claim 12 , wherein the at least one performance metric is exponentially related to a time of expiration of a packet.