A Hybrid MAC Scheme for Emergency Systems in Urban VANETs ... · A Hybrid MAC Scheme for Emergency...
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A Hybrid MAC Scheme for Emergency Systems in Urban VANETs Environment
Saifullah Khan*, Muhammad Alam†, Nils Müllner‡ and Martin Fränzle** Carl von Ossietzky University Oldenburg, Germany
†Instituto de Telecomunicaçoes, University of Averio, Portugal‡ Mälardalen University 721 23, Västerås, Sweden
HyMAC Scheme Modes
Proposed Scheme
• The proposed scheme is called Hybrid MAC (HyMAC).• To reduce the Interference between neighboring
interfaces.
• Minimizing flooding of its control packets.
• Input: Expected load on each channel.
• Output: Channels assignment and channel utilization.
• uses a time-triggered scheduling, which is controlled
by time points.
• The objective here is to switch the network mode for
MAC layer between CCH and SCHs.
• The nodes should communicate without extra delay
and utilize less channel consumption.
• CCH and SCHs are treat as CSMA and TDMA.
• Priority should be the same for the all emergency
messages, so scheduling for these messages in a fully
distributed way.
• CCH should be utilize completely all the time.
Motivation & Objectives
Performance Evaluation
Contact: Saifullah Khan [[email protected]]Carl von Ossietzky University of Oldenburg, Germany.
Mode 1: Channel mode in normal situation.
Mode 2: Channel mode in emergency situation.
(a) Control channel utilization vs. node density (b) Collision probability of the SCHs vs. node density (c) Control channel utilization vs. transmission probability (d) Throughput vs. offered transmission load (e) Data delivery ratio vs. number of nodes.
a b c
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