A coding and retransmission protocol for mobile radio data transmission

Mobile radio systems suffer from severe channel impairments. As services are moving toward a full extension of those available over fixed networks, new coding strategies are being developed to support data traffic beside the more usual voice communication. This paper presents a modified type II hybrid FEC/ARQ protocol in which each packet to be transmitted is decomposed into sub-packets each of which can be independently tested for correctness and retransmitted if necessary. The complete coding and transmission scheme is designed to be compatible with the frame format used in GSM networks. The performances of the proposed algorithm are evaluated by computer simulation using the system specifications contained in the ETSI-GSM recommendations. Throughput comparison with a traditional selective repeat (SR) protocol is presented to support the robustness and effectiveness of the presented scheme.