Retransmission DBTMA Protocol With Fast Retransmission Strategy to Improve the Performance of MANETs

The Mobile Ad-hoc Networks (MANETs) are often visible to the exposed terminal problem and hidden terminal problem, which exist due to non-transitivity in media access control schemes. This affects the utilization of channel and throughput in media access control protocols, e.g., dual busy tone multiple access protocol (DBTMA). Hence, to improve the fairness and throughput performance of the DBTMA it is very necessary to address the problems associated with hidden and exposed terminals. Hence, in this paper, the quality of service (QoS) is improved by enhancing the capability of the DBTMA for better network service in the MANETs. The proposed method uses an improved DBTMA called Retransmission Dual Busy Tone Multiple Access (RDBTMA) protocol. This is based on two elements namely: busy tones and Ready To Send/Clear to Send (RTS/CTS) dialogues. In addition to this fast retransmission, a strategy is used further to improve its effectiveness. The retransmission strategy is adopted using negative acknowledgment after the collision occurred by the hidden nodes. A hidden node, where the collision occurs at access point, listens to the NACK signal and uses the signal to determine the requirement fast retransmission scheme. The proposed method is simulated and compared against existing methods in terms of various network parameters. The results show that the proposed RDBTMA protocol is effective in terms of the improved QoS in terms of network throughput (21.9%), packet delivery ratio (17.8%), 14.9% less packet loss, and 38% less route discovery delay than the existing methods.