¿µ¹®³»¿ë (English Abstract) |
3GPP RLC protocol specification adopted an error control scheme based on selective-repeat ARQ. In the 3GPP¡¯s ARQ, distinctive windows are installed at the transmitting and receiving stations so that each station is prohibited to send or admit a data PDU out of its current window. As a member of selective-repeat ARQ clan, a classical problem of re-ordering is inherent in 3GPP¡¯s ARQ. While a decrease in window size reduces the occupancy of the re-ordring buffer, such a decrease incurs degradation in throughput performance. Aiming at reducing the occupancy of the re-ordering buffer as well as suppressing the deterioration of throughput performance, we propose upper and lower go-back-N schemes as easily implementable supplements to the 3GPP¡¯s ARQ. In the upper (lower) go-back-N schemes, a threshold is created in the receiving station¡¯s window and a data PDU whose sequence number is higher (lower) that the threshold is treated according to a go-back N ARQ. For the evaluation of proposed schemes, we investigate peak occupancy and maximum throughput in ther simulation environments characterized by bursty PUD arrivals and Markov channels reflecting fading phenomenon. From simulation results, we conclude that the upper go-back-N scheme is able to improve the throughput performance of the 3GPP¡¯s ARQ without inflating the occupancy of the re-ordering buffer.
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