Maca-Apt

Abstract

In wireless communications, collision is one of the principal sources of energy wastage, which often makes collision avoidance strategies preferred for medium access control (MAC) protocols. In this paper, we propose a collision avoidance-based MAC protocol called MACA-based Adaptive Packet Train (MACA-APT), which has been designed specifically for underwater acoustic networks (UANs). The design explicitly accounts for prominent characteristics of UANs such as long propagation delays and typically high bit error rates. In particular, the former is compensated via the transmission of multiple consecutive packets to multiple different receivers; the latter, instead, is tackled by embedding a cross-layer Stop-&-Wait ARQ scheme within MACA-APT.The performance of the proposed protocol is evaluated via simulations and compared to another MAC protocol, also based on MACA, showing that MACA-APT achieves better performance for low to intermediate packet generation rates, and equivalent performance at higher rates. Moreover, we assess the impact of the packet train size on the performance of either protocol. This result is a first step towards the design of adaptive multi-packet multi-receiver MAC protocols for underwater networks.

DAMAC: A Delay-Aware MAC Protocol for Ad Hoc Underwater Acoustic Sensor Networks

“…Communication overhead [28][29][30] The communication overhead is related to how many packets are required to transmit data between intended parties. The MAC protocols that rely on the handshake-based approach result in high COR.…”

“…The handshake-based approach is widely used to resolve collision issues, but it results in low channel use, low network throughput, and high E2ED due to the characteristics of acoustic channels [28][29][30]33]. Therefore, in this paper we propose DAMAC protocol, which avoids the handshaking packets prior to data transmission and schedules nodes to transmit their packets while reducing the collision rate [14,20,31,32].…”

“…The traditional handshaking MAC protocols, such as S-FAMA [43], Multi-session FAMA (M-FAMA) [45,46], Multiple Access with Collision Avoidance Adaptive Packet Train (MACA-APT) [28], and MACA-based Power Control (MACA-PC) [35], employ RTS/CTS packets to reserve a channel. The RTS packet is used to request channel reservation, while the CTS packet replies to a received RTS packet.…”

“…Due to the characteristics of acoustic channel, packets can be lost and must be retransmitted. When packets are lost in S-FAMA [43], M-FAMA [45,46], MACA-APT [28], MACA-PC [35], and OPMAC [47], the source must retransmit the lost packets via any data channel as illustrated in Figure 3. This process increases the end-to-end delay.…”