Temporally enhanced erasure codes for reliable communication protocols
In forward error correction (FEC), redundant encoded packets are transmitted to and decoded by receiver(s) so that up to a certain number of lost packets can be recovered by using those redundant packets. The data stream is divided into blocks, and encoded packets are generated within each block. Hence, the encoding and decoding are performed on block-by-block basis. In this paper, a new mechanism named as temporally enhanced FEC (TEFEC) is proposed as an enhancement to the existing block-based FEC codes such as erasure codes. In TEFEC, the scopes of encoding and decoding are expanded beyond block boundaries, and they may overlap with scopes of neighboring blocks. To show its feasibility, TEFEC is applied to erasure codes to enhance their error correction capability, and new codes named as temporally enhanced erasure codes (TEEC) are developed and presented in this paper. In addition, to show its advantages, a reliable protocol was designed and simulated by combining both automatic repeat request and TEEC techniques. In terms of average packet retransmission rates and end-to-end delays for packet delivery, it is shown that the protocol employing TEEC outperforms block-by-block based protocols in most of the cases.
erasure codes communication protocol fec error recovery arq