Dynamic Cooperative Retransmission Scheme for TDMA Systems

In this letter, we propose and analyze a dynamic cooperative retransmission scheme for TDMA systems in multi-hop networks. Our scheme cooperatively retransmits a failed packet during a neighbor node´s idle slot, which is selected using a simple mechanism. If an idle slot is not available, cooperative retransmission is attempted during the source node´s time slot. The throughput of TDMA can be significantly improved by cooperative retransmission. We formulate an analytical model for the proposed scheme that can be implemented over Rayleigh fading channels. The results showed that the throughput of TDMA systems was improved significantly if a sufficient number of idle slots were available for cooperative retransmission, although an overhead was introduced.