where it goes to the Internet (Fig. 13.1). Mesh networks decrease the cost of running the access points, as all access points in the same area share a single broadband connection. Current mesh networks use 802.11a technology to interconnect the mesh backbone [3,4]. However, 802.11a technology is a decade old and was not designed for mesh networks. In particular, 802.11 Medium Access Control (MA...

Cognitive radio technology has been developed in recent years to make efficient use of the wireless spectrum especially for opportunistic spectrum access. Cognitive radio technology enables the secondary (cognitive) users to use the unused licensed spectrum of the primary users. Medium Access Control (MAC) protocol plays a vital role in spectrum utilization, primary user’s (PU) interference man...

Performance of Wireless LAN can be improved at each layer of the protocol stack with respect to energy efficiency. The Media Access Control layer is responsible for the key functions like access control and flow control. During contention, Backoff algorithm is used to gain access to the medium with minimum probability of collision. After studying different variations of back off algorithms that...

Control/command processes require a transmission system with some characteristics like high reliability, low latency and strong guarantees on messages delivery. Concerning wire networks, field buses technologies like FIP offer this kind of service (periodic tasks, real time constraints...). Unfortunately, few wireless technologies can propose a communication system which respects such constrain...

This paper presents the design of a Cooperative Collision Avoidance application, and evaluates its performance with DSRC-recommended 802.11 Medium Access Control (MAC) and with a novel Vehicular SelfOrganizing MAC (VeSOMAC) protocol. VeSOMAC is designed as a fully distributed TDMA protocol that relies on an in-band control exchange technique for autonomous TDMA slot allocation among vehicle-mou...

The IEEE 802.11 wireless LAN (WLAN) is based on carrier sense multiple access with collision avoidance (CSMA/CA) protocol. CSMA/CA uses a backoff mechanism to avoid collisions among stations (STAs). One disadvantage of backoff mechanisms is that STAs must wait for some period of time before transmission, which degrades spectral efficiency. Moreover, a backoff algorithm cannot completely avoid c...

Consider the problem of scheduling sporadic messages with deadlines on a wireless channel. We propose a collision-free medium access control (MAC) protocol which implements static-priority scheduling and present a schedulability analysis technique for the protocol. The MAC protocol allows multiple masters and is fully distributed; it is an adaptation to a wireless channel of the dominance proto...

Corresponding Author: Marcos F. Caetano Department of Computer Science, University of Brasília, Brasília, Brazil Email: [email protected] Abstract: Wireless technologies have permeated a significant number of devices over the years. On the other hand, Medium Access Control (MAC) protocols strive to deal with an increasing number of contending nodes on crowded frequency bands. This work presents ...

In this paper, we present a collision-free asynchronous multi-channel access protocol for Ad Hoc wireless networks using a single transceiver. Our protocol, dubbed AMMAC for Asynchronous Multi-channel Medium Access Control, targets low-cost and low-power deployments where nodes are equipped with a single transceiver. Other distinguishing features of AM-MAC include its simplicity and the fact th...