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Showing papers by "Celimuge Wu published in 2012"


Proceedings ArticleDOI
01 Dec 2012
TL;DR: A VANET routing protocol which learns the optimal route by employing a fuzzy constraint Q-Learning algorithm which uses a fuzzy logic to evaluate a wireless link is whether good or not by considering multiple metrics of signal strength, available bandwidth and relative vehicle movement.
Abstract: Vehicular ad hoc networks (VANETs) can be used for the purpose of driving assistance, environment monitoring and entertainment. However, due to the vehicle movement, limited wireless resources and lossy feature of wireless channel, providing a reliable multi-hop communication in VANETs is particularly challenging. In this paper, we propose a VANET routing protocol which learns the optimal route by employing a fuzzy constraint Q-Learning algorithm. The protocol uses a fuzzy logic to evaluate a wireless link is whether good or not by considering multiple metrics of signal strength, available bandwidth and relative vehicle movement. Based on the evaluation of each wireless link, the proposed protocol learns the best route using the route request messages and hello messages. Upon reception of a route request message, each node maintains an evaluation value for each possible next hop node. In this way, the protocol can choose the best route, which is difficult to acquire in a typical reactive routing protocol. We show the effectiveness of the proposed protocol by using computer simulations.

25 citations


Proceedings ArticleDOI
25 Oct 2012
TL;DR: A data collection and dissemination framework for cognitive radio sensor systems to fully utilize wireless resources while maintaining a reliably connected and efficient topology for each channel.
Abstract: With the increase of the number of wireless sensing or metering devices, the collection of sensing data using wireless communication becomes an important part of many applications. Cognitive radio technology can be used to facilitate the deployment of a bandwidth efficient sensor system. In this paper, we propose a data collection and dissemination framework for cognitive radio sensor systems to fully utilize wireless resources while maintaining a reliably connected and efficient topology for each channel. In the proposed framework, each sensor node selects a channel considering primary user channel utilization and network connectivity. In this way, the data collection and dissemination can be performed with a high reliability and short delay while avoiding a harmful effect on primary users. We use computer simulations to evaluate the proposed framework.

10 citations


Proceedings ArticleDOI
16 May 2012
TL;DR: A redundancy-based approach to provide a high reliability while maintaining a low end-to-end delay is proposed and implemented on a wireless sensor network which consists of IRIS motes and the performance of the proposed mechanism is evaluated.
Abstract: Wireless sensor networks (WSNs) can be used for a variety of applications For many applications, a high reliability and low delay are required Due to lossy feature of wireless channel, providing a reliable communication is very challenging The most frequently used approach for providing the reliability is to use the acknowledgement based retransmission mechanism which increases the end-to-end delay especially when the number of hops from a sensor to the sink node is large In this paper, we propose a redundancy-based approach to provide a high reliability while maintaining a low end-to-end delay The proposed mechanism uses a redundant transmission when a link is unreliable or the end-to-end delay requirement is strict We implement the proposed mechanism on a wireless sensor network which consists of IRIS motes, and evaluate the performance of the proposed mechanism

6 citations


Proceedings ArticleDOI
01 Nov 2012
TL;DR: A broadcast protocol which does not require position information is proposed which uses two-hop neighbor information to select relay nodes which are used to forward a packet and uses a joint redundancy and opportunistic transmission approach to recover a packet loss.
Abstract: In vehicular ad hoc networks (VANETs), a multi-hop broadcast protocol is required to disseminate traffic warning information to multiple receivers. Reducing broadcast message overhead is important because it could directly affect the packet collision probability and MAC layer contention time at each node. There have been some broadcast protocols for VANETs. However, many of them assume the availability of the global positioning system. In this paper, we propose a broadcast protocol which does not require position information. The protocol uses two-hop neighbor information to select relay nodes which are used to forward a packet. The proposed protocol also uses a joint redundancy and opportunistic transmission approach to recover a packet loss. We show the effectiveness of the proposed protocol by evaluating in a real vehicular ad hoc network.

5 citations


Book ChapterDOI
16 Mar 2012
TL;DR: A Vehicular Ad hoc Network (VANET) is a form of mobile ad hoc network in which vehicles are equipped with wireless communication devices to reduce the number of road accidents and make the driving more efficient by disseminating traffic warning information and service information.
Abstract: A Vehicular Ad hoc Network (VANET) is a form of mobile ad hoc network in which vehicles are equipped with wireless communication devices Vehicular ad hoc networks have been attracting the interest of both academic and industrial communities on account of their important role in Intelligent Transportation Systems (ITS) VANETs are expected to be able to significantly reduce the number of road accidents When vehicles travel at a high speed on roads, drivers have very little time to react to the vehicle in front of them By using vehicular ad hoc networks, emergency information can be propagated along the road to notify drivers ahead of time so that necessary actions can be taken to avoid accidents Vehicular ad hoc networks also make the driving more efficient by disseminating traffic warning information and service information

5 citations