Ordered CSMA: a collision-free MAC protocol for underwater acoustic networks

Abstract

Since underwater acoustic (UWA) networks have the nature of long propagation delay, low bit rates and error-prone acoustic communication, protocols designed for underwater acoustic networks are significantly different from that of terrestrial radio networks. Limited by these nature of UWA channels, conventional medium access control (MAC) protocols of radio packet network ether have low efficiency or are not able to apply to underwater acoustic networks. It is necessary to develop an efficient MAC protocol for underwater acoustic networks. In this paper, a collision-free MAC protocol for UWA networks called Ordered Carrier Sense Multiple Access (Ordered CSMA) is proposed and analyzed. Ordered CSMA combines the concepts of round-robin scheduling and CSMA. In Ordered CSMA, each station transmits data frame in a fixed order. More specifically, each station transmits immediately after the data frame transmission of last station in the order, instead of waiting for a period of maximum propagation delay. To achieve this, each station is constantly sensing the carrier and listens to all received frames. Due to the characteristics of collision free and high channel utilization, Ordered CSMA shows a great MAC efficiency improvement in our simulations, compared to previous works.

The Feasibility of Exploiting IEEE 802.11n for Addressing MAC Layer Overheads in UASNs

“…There have been many trials to use them for acoustic communications in UASNs [2,7,8]. CSMA requires a node to sense medium for the potential ongoing communication before it attempts to access the medium.…”

L-MAC: Localization packet scheduling for an underwater acoustic sensor network

“…It can be deduced that optimum OCSMA is the optimal solution of the localization time minimization if each anchor is in the acoustic communication range of all the other anchors. Finding the optimum solution of OCSMA is NP-hard [7]. Hence, we again use the concept of the first and best starter for this algorithm, and we compare its performance to ours.…”

“…They show that the performance of a simple MAC protocol, namely carrier sense multiple access (CSMA), is better than T-Lohi [5] (a recently designed underwater MAC protocol). The paper [6] uses a previously proposed scheduling protocol, ordered CSMA (OCSMA) [7], for broadcasting massages from the anchors. In OCSMA, a coordinator finds the transmission sequence based on the full knowledge of the relative positions of the anchors, and informs them of the resulting sequence.…”

An Enhanced Dynamic Token Protocol for Underwater Acoustic Sensor Networks

“…ST-MAC uses spatial-temporal conflict graph and vertex coloring methods to overcome spatial-temporal uncertainty in UWASNs. In [6], an ordered carrier sense multiple access (Ordered CSMA) is proposed for single-hop UWASNs. The Ordered CSMA allows multiple carriers from multiple sources to propagate at the same time.…”