Conference Paper

Dynamic Adaptation of Joint Transmission Power and Contention Window in VANET

Dept. of Electr. & Comput. Eng., Old Dominion Univ., Norfolk, VA, USA
DOI: 10.1109/VETECF.2009.5378793 Conference: Vehicular Technology Conference Fall (VTC 2009-Fall), 2009 IEEE 70th
Source: IEEE Xplore


In this paper, we propose an algorithm for joint adaptation of transmission power and contention window to improve the performance of vehicular network in a cross layer approach. The high mobility of vehicles in vehicular communication results in the change in topology of the Vehicular Ad-hoc Network (VANET) dynamically, and the communication link between two vehicles might remain active only for short duration of time. In order for VANET to make a connection for long time and to mitigate adverse effects due to high and fixed transmission power, the proposed algorithm adapts transmission power dynamically based on estimated local traffic density. In addition to that, the prioritization of messages according to their urgency is performed for timely propagation of high priority messages to the destination region. In this paper, we incorporate the contention based MAC protocol 802.11e enhanced distributed channel access (EDCA) mechanism to implement a priority-based vehicle-to-vehicle (V2V) communication. Simulation results show that the proposed algorithm is successful in getting better throughput with lower average end-to-end delay than the algorithm with static/default parameters.

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Available from: Michele Weigle
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    • "(i) Simulation tool: to evaluate performance of the proposed hybrid adaptive beaconing schemes, different simulation tools have been used by the authors. For example, network simulator (ns-2), an open source simulator, has been used in[43,44,47,48]and OPNET (a proprietary software for network performance management) has been employed by[25,49]. "
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    ABSTRACT: Beacon or safety messages are broadcasted in vehicular ad hoc networks (VANETs) to disseminate network state or emergency incident information to other vehicles in the network. The freshness of information depends upon the frequent transmission of beacons. Similarly, to increase the awareness area or communicating with the distant nodes, beacons are disseminated with a high transmission power. However, increasing the beacon transmission power or rate has a negative effect on information communication efficiency because of the finite bandwidth of the wireless link. Therefore, different schemes have been proposed to individually control beacon’s transmission power, transmission rate, or contention window at the MAC layer, or any combination of those, to achieve quality beacon communication in VANETs. The latter case is called hybrid adaptive beaconing schemes. In literature, there are many hybrid adaptive beaconing schemes that control multiple communication parameters to efficiently broadcast beacon messages in VANETs. In this paper, we explicitly survey and summarized various aspects of those schemes. The open and challenging issues are also highlighted in this paper.
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    • "It can risk to deliver the Emergency Safety Application (ESA) messages because they are queued when the congestion in channel occurs or message rate reaches its maximum threshold. As the threshold values are used for the density of vehicles and also for the collision in the channel, the protocol proposed in [7] does not seem to be scalable. Anyhow, the simulation results show the lower delays by prioritizing the different type of message and high throughput. "
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    ABSTRACT: In vehicular ad hoc networks, the dynamic change in transmission power is very effective to increase the throughput of the wireless vehicular network and decrease the delay of the message communication between vehicular nodes on the highway. Transmission range is directly proportional to the transmission power the moving node. If the transmission power will be high, the interference increases that can cause higher delay in message reception at receiver end, hence the performance of the network decreased. In this paper, it is analyzed that how transmission power can be controlled by considering other different parameter of the network such as; density, distance between moving nodes, different types of messages dissemination with their priority, selection of an antenna also affects on the transmission power. The dynamic control of transmission power in VANETs serves also for the optimization of the resources where it needs, can be decreased and increased depending on the circumstances of the network. Different applications and events of different types also cause changes in transmission power to enhance the reach-ability. The analysis in this paper is comprised of density, distance with single hop and multi-hop message broadcasting based dynamic transmission power control as well as antenna selection and applications based. Some summarized tables are produced according to the respective parameters of the vehicular network. At the end some valuable observations are made and discussed in detail. This paper concludes with a grand summary of all the protocols discussed in it.
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    • "Studies have also considered the use of transmitter power control as a mechanism for trading off network connectivity and radio interference between vehicles [5] [10] [11]. The energy efficiency for VANETs however, has typically not been an issue, as vehicle engines provide virtually unlimited energy. "
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