Asynchronous blind MAC protocol for wireless sensor networks

Abstract

Abstract-In the past few years, energy conservation has been the main focus of researchers working on wireless sensor networks. One of the main technique to save energy is to deactivate periodically the radio module of sensor nodes: nodes alternate periods of activity and periods of inactivity, which is referred to as their duty-cycle. In this paper, we focus on asynchronous dutycycle mechanisms, as these mechanisms are usually simple, do not require time synchronization and support network changes. We propose an asynchronous MAC protocol based on blind rendez-vous and random wake-up. Our protocol is based on a modification of the IEEE 802.15.4 standard, where activities start at a random time within each activity cycle. Our simulations show that our protocol can achieve a good performance under various scenarios, for small duty cycles (ranging from 0.1% to 5%).

SLACK-MAC: Adaptive MAC Protocol for Low Duty-Cycle Wireless Sensor Networks

“…For the protocol of [26], the packet delivery ratio increases from 79% to 99%. The packet delivery ratio is high: indeed, when nodes meets, they can benefit from this meeting time, as there are few simultaneously active nodes.…”

“…In order to evaluate the performance of SLACK-MAC, we conducted several simulations to compare SLACK-MAC with the protocol of [26] and with X-MAC [17] (as it is one of the most representative asynchronous MAC protocols). We also compared SLACK-MAC with the main MAC protocol with synchronized duty-cycle, which is the standard ZigBee [27].…”

“…Figure 5 (left) shows the packet delivery ratio as a function of the traffic generation period for ZigBee, X-MAC [17], the protocol of [26] and SLACK-MAC. The traffic generation period ranges from 5 seconds (which corresponds to a high traffic generation for a duty-cycle of 1%) to 20 seconds (which corresponds to a relatively low traffic generation for such duty-cycle).…”

“…The MAC protocol proposed in [26] is based on random wake-up times. Each node knows the duration of the cycle, denoted by C, and the duration of its activity within each cycle, denoted by A.…”

“…However, for n 1 to communicate with n 3 , both nodes have to wait until the middle of the third cycle of n 1 . Example of the activities of three neighbor nodes with the protocol of [26], with a dutycycle of 25% (this long duty-cycle is chosen for clarity).…”