The performance of multipath ARQ protocols to achieve higher throughput in a wireless network and molecular communication

Abstract

In Automatic Repeat reQuest(ARQ) methods, if the receiver receives an erroneous copy then it discards the erroneous copy and acknowledges by sending the negative acknowledgement for the retransmission of duplicate copies. In order to reduce the retransmission of duplicate copies and also to recover the correct copy after storing the erroneous copies, Packet Combining technique is well studied. The limitation of PC is: the technique fails when error(s) location(s) is at the same position of erroneous copies. Thus, the throughput of PC is 50% with one bit error correction capability. On the other hand, modified Packet Combining technique performs pair-wised XOR from the received erroneous copies and it is used to find out the minimum number of bit-erroneous location among the combined erroneous copies. Thus, MPC provides higher error correction capability by correcting two bits error but lower throughput than PC. For improving the throughput of normal ARQ protocols; Aggressive Packet Combining technique has implemented in a wireless network. But, the maximum throughput which can be attained by APC is only 33% if the scheme is recovered the original copy. However, several researchers have also been studied and conclusively established different modification techniques of ARQ and APC to improve the error control and system performance in a wireless network but lacked of addressing the concept of processed or half-corrected erroneous copies after implementing the PC or MPC techniques. In order to utilize the processed erroneous copies, new combined technique of PC, MPC and APC is presented for improving the performance of MPC and APC techniques. The proposed protocol consists of three blocks; PC block, PC+MPC block, and MPC+APC block. Two copies of the same packet are sent from Transmitter to Receiver. If both the copies are found as erroneous then PC technique is used to correct the original copy in the PC block and if it is not obtained a successful copy then the Rx requests for a third copy.