Packet Scheduling Algorithm with Modified Time-Utility Function to Improve NRT Throughput in OFDMA System

We propose a packet scheduling algorithm to improve the throughput performance of non-real time (NRT) traffic while satisfying quality of service (QoS) of real-time (RT) traffic in orthogonal frequency division multiple access (OFDMA) system compared to the conventional algorithm. In order to support both RT and NRT packets adaptively in the varying traffic situation, the proposed algorithm adjusts the length of marginal scheduling time interval (MSTI) for the time-utility function (TUF), which is related to the urgency of packets in time at a base station. In the proposed algorithm, if both the number of NRT traffic packets in buffers for each user become zero, the lengths of MSTI for voice traffic and video traffic are adjusted to the maximum available delays of voice and video traffic. Computer simulation results show that the proposed algorithm is able to provide less packet loss rate for RT traffic and better throughput performance for NRT traffic.