Performance Analysis on SR ARQ with Any Size of Buffer

Selective Repeat ARQ protocol has been widely used in communication network for reliable data transfer. However the performance of SR ARQ protocol was not well studied. There is some approximate performance analysis for SR ARQ. But under many cases, such as the large bandwidth-delay case, the approximation shows a large inaccuracy. In this paper we study the characteristics of SR ARQ first, then present an analytical computation method for SR ARQ with any finite buffer. An approximate performance formula for SR ARQ is also given. The analytical result on performance analysis gives a relatively accurate relationship between throughput and the physical error ratio, the channel bandwidth, the transfer delay, and any buffer size. Two conventional analytical methods are compared with our methods. Comparison results show that our methods are more accurate.