Low Complexity Fair Scheduling in LTE/LTE-A Uplink Involving Multiple Traffic Classes

The bulk of the research on long term evolution/long term evolution-advanced [(LTE)/(LTE-A)] packet scheduling is concentrated in the downlink and the uplink and is comparatively less explored. In uplink, channel aware scheduling with throughput maximization has been widely studied while considering an infinitely backlogged buffer model, which makes the investigations unrealistic. Therefore, we propose an optimal uplink packet scheduling procedure with realistic traffic sources. First, we advocate a joint channel and buffer aware algorithm, which maximizes the actual transmitted bit-count. Thereafter, we introduce delay constraints in our algorithm to support real-time traffic. We further enhance our algorithm by incorporating the varied delay and throughput requirements demanded by mixed traffic classes. Finally, we introduce priority flipping to minimize bandwidth starvation of lower priority traffic in the presence of higher percentage of high priority traffic. We observe that a delay constraint may render the optimization-based proposals infeasible. Therefore, to avoid infeasibility, we replace the delay constraint with delay outage minimization (DOM). DOM aims at minimizing the packet drop due to delay violation. Moreover, DOM also helps in reducing the problems to a well-known assignment problem, which can be solved by applying the Hungarian algorithm. Hence, our approach delivers an optimal allocation with low computational complexity.