In this paper, UW-MAC, a distributed Medium Access Control (MAC) protocol tailored for UnderWater Acoustic Sensor Networks (UW-ASNs), is proposed. It is a transmitter-based Code Division Multiple Access (CDMA) scheme that incorporates a novel closed-loop distributed algorithm to set the optimal transmit power and code length. UW-MAC aims at achieving three objectives, i.e., guarantee high netwo...

This dissertation discusses some techniques to improve the medium access control in infrastructure multi channel wireless local area networks. Medium Access Control protocols (MAC) coordinate the stations and resolve the channel contentions so that scarce radio resources are shared fairly and efficiently amongst participating users. We propose different models to improve the medium access contr...

1. Research overview Energy efficiency is the chief concern in sensor networks as they have limited power and it often requires tradeoffs with throughput and latency when designing a medium access control (MAC) protocol. The goal of this research is to maximize energy savings based on sleep mode operation and Transmit Power Control (TPC) to save power in Mote-based sensor networks. Two key obje...

Conventional Medium Access Control (MAC) protocols perform quite well for the traffic types they have been designed for, but poorly for other traffic streams with different characteristics. But, the emerging multimedia applications require that the MAC protocol should perform equally well for all types of traffic characteristics. In this paper, we propose an integrated MAC protocol (herein term...

In this paper, we address the congestion control multicast routing problem in wireless ad hoc networks through the medium access control (MAC) layer. We first introduce the Broadcast Medium Window (BMW) MAC protocol, which provides reliable delivery to broadcast packets at the MAC layer. We then extend the wireless On-Demand Multicast Routing Protocol (ODMRP) to facilitate congestion control in...

Emergency services, and automated vehicle platoons are frequently used examples of the need for real-time ad hoc communication, which demand that communication be time bounded overall. The medium access control protocol regulates access to the medium. Time division protocols give deterministic, time bounded delivery of messages. TDMA, time division multiple access forms the basis of the time bo...

Nodes in a wireless network transmit messages through a shared medium. Thus, a Media Access Control (MAC) protocol is necessary to regulate and coordinate medium access. For some application areas it is necessary to have a deterministic MAC protocol which can give guarantees on message delay and channel throughput. Schedule based MAC protocols, based on time synchronization among nodes, are cur...

We evaluate the performance of an opportunistic multi-channel medium access control protocol and compare it to that of the corresponding single-channel MAC (S-MAC) and a nonopportunistic multi-channel MAC (M-MAC). We do this in three different settings: (1) an ideal scenario where no control channel is used and no sensing delay is incurred, (2) a more realistic scheme where users compete for ac...

Cognitive Radio (CR) is a promising technique to address the spectrum scarcity issue by enabling the unlicensed network users (SUs) to dynamic access the spectrum holes. This thesis designs Medium Access Control (MAC) protocols for SUs to utilize the unused spectrum without interfering the licensed network users’ (PUs) transmissions; analyzes the MAC performance based on the queuing theories; a...

This paper gives a short overview of the state of the art of time-division multiple access (TDMA) based medium access control (MAC) protocols for wireless sensor networks (WSN). These sensor networks have special requirements on MAC protocols, which make it impossible to function efficiently with the help of ordinary wireless MAC protocols. Research challenges and state of the art are described...