Performance Improvement in Broadband Networks Using Forward Error Correction for Lost Packet Recovery

Abstract

In this paper we analyze and provide simulation results for the use of forward error control (FEC) to improve the delay-throughput performance of packetized high-speed networks. The major source of errors in high-speed networks is expected to be buffer overflow during congested conditions, resulting in lost packets. A single lost or errored packet will have to be retransmitted, or may even cause the window it belongs to to be retransmitted, causing a large delay. In high-speed networks, as in satellite and deep-space systems, the effect of retransmission delays is greatly amplified by the small ratio of packet duration to propagation delay. Consequently, the performance of delay sensitive applications, such as distributed processing, will be degraded by the retransmissions associated with the conventional error detection and retransmission (ARQ) protocols. FEC can be used to make the performance of the end-to-end system much less sensitive to packet loss. The result is a significant increase in network throughput and an associated decrease in delay, since retransmissions are avoided. Also, reliable transmission might permit simpler higher-layer processing. Because of the performance gains described above, the use of FEC is a strong candidate for inclusion in high-speed network protocols for delay and loss sensitive applications.