13,697 research outputs found
H-MAC: A Hybrid MAC Protocol for Wireless Sensor Networks
In this paper, we propose a hybrid medium access control protocol (H-MAC) for
wireless sensor networks. It is based on the IEEE 802.11's power saving
mechanism (PSM) and slotted aloha, and utilizes multiple slots dynamically to
improve performance. Existing MAC protocols for sensor networks reduce energy
consumptions by introducing variation in an active/sleep mechanism. But they
may not provide energy efficiency in varying traffic conditions as well as they
did not address Quality of Service (QoS) issues. H-MAC, the propose MAC
protocol maintains energy efficiency as well as QoS issues like latency,
throughput, and channel utilization. Our numerical results show that H-MAC has
significant improvements in QoS parameters than the existing MAC protocols for
sensor networks while consuming comparable amount of energy.Comment: 10 pages, IJCNC Journal 201
Adaptive multi-channel MAC protocol for dense VANET with directional antennas
Directional antennas in Ad hoc networks offer more benefits than the traditional antennas with omni-directional mode. With directional antennas, it can increase the spatial reuse of the wireless channel. A higher gain of directional antennas makes terminals a further transmission range and fewer hops to the destination. This paper presents the design, implementation and simulation results of a multi-channel Medium Access Control (MAC) protocols for dense Vehicular Ad hoc Networks using directional antennas with local beam tables. Numeric results show that our protocol performs better than the existing multichannel protocols in vehicular environment
UWB MAC Design Constraints and Considerations
In this paper, we consider the possibility of developing an optimal medium access control (MAC)layer for high data rate ultra-wideband (UWB) transmission systems that transmit minimal power. MAC in UWB wireless networks is required to coordinate channel access among competing devices. The unique UWB characteristics offer great challenges and opportunities in effective UWB MAC design. We first study the background of UWB and available MAC protocols that have been used in UWB. Secondly, we explore the constraints on UWB MAC design. Finally we present the considerations that need to be made in designing an optimal UWB MAC protocol
Self-Stabilizing TDMA Algorithms for Dynamic Wireless Ad-hoc Networks
In dynamic wireless ad-hoc networks (DynWANs), autonomous computing devices
set up a network for the communication needs of the moment. These networks
require the implementation of a medium access control (MAC) layer. We consider
MAC protocols for DynWANs that need to be autonomous and robust as well as have
high bandwidth utilization, high predictability degree of bandwidth allocation,
and low communication delay in the presence of frequent topological changes to
the communication network. Recent studies have shown that existing
implementations cannot guarantee the necessary satisfaction of these timing
requirements. We propose a self-stabilizing MAC algorithm for DynWANs that
guarantees a short convergence period, and by that, it can facilitate the
satisfaction of severe timing requirements, such as the above. Besides the
contribution in the algorithmic front of research, we expect that our proposal
can enable quicker adoption by practitioners and faster deployment of DynWANs
that are subject changes in the network topology
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