Performance improvements of data-link layer protocol in WATM

In these days, a mobile communication service has high-speed and multimedia characteristics. Due to the high error ratio of wireless link environments, a DLC protocol that is optimized for a wire network could not be used in wireless link environments. Thus, the DLC protocol that is suitable for mobile communication environments is required. To solve these problems, we propose an efficient WATM DLC layer protocol. The proposed DLC protocol could support various traffic attributes of high-speed multimedia services. That is, the proposed DLC layer protocol provides a piggyback response, the multiple-ack, and a multiple retransmission mechanism based on SR-ARQ. Also, an outband retransmission scheme using dynamic bandwidth is provided for the delay sensitive service and multi-copy transmission is applied in seriously faded radio environments such as handover. According to the simulation results, the suggested schemes show a better performance than the conventional SR-ARQ protocol in view of the cell transmission delay and throughput