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Contention-based MAC protocol in UWSNs: Slotted_CS_ALOHA proposed protocol

Energy in MAC protocols becomes an important research issue because sensor nodes are mostly take their power from batteries that are not easily to be recharged. The aim of this paper is to improve MAC protocol in underwater sensor networks by enhancing the performance of ALOHA protocol, which considered as one of the most popular MAC protocols. This work proposed a method for preserving the energy consumption in underwater sensor networks. We propose a protocol that we called Slotted_CS_ALOHA. This approach based on three stages before the original Aloha cycles is working, the first stage is buffer that if the node has any numbers of packet it will be able to send them continuously to the buffer. The second stage has two parallel steps the first one is a slot time that check if slot time begins or not. The second one is CS to check if channel free or not by sending small message (RTS and CTS) to make sure that channel is free. The third stage considered as another buffer. Our simulation results demonstrate that the proposed protocol efficiently reduces energy consumption especially in dense networks, increases the throughput ratio, increases the alive nodes ratio, and reduces the dropped node. On the other hand, our proposed cannot decrease the average delay.