20 research outputs found
Evaluation of Quality of Service (QoS) Support for Real-Time or Mission Critical Services over IEEE 802.11e Wireless Networks
No full textInvestigation of quality of services (QoS) support for real-time or mission critical services over IEEE 802.11e wireless networks.
No full textMultimedia application is currently making much impact in this technological era. It has been thekey driving force behind the convergence of fixed, mobile and IP networks. Furthermore, real-timeapplications are making head way in vehicular networks, mission critical applications which usededicated short range communications (DSRC). 802.l i e standards support quality of services(QoS) guarantees in these applications. This is opposed to the problem with 802.11 legacy whichis based on distributed coordination function (DCF), and its inability to prioritized applications forservice differentiation. Simulation was done on various 802.l i e networks which use enhancedDCF (EDCF). In these simulations, it was observed that controlling low priority applicationsenhances the effectiveness of high priority applications. Different MAC and traffic generationparameters were used in various scenarios. It was actually observed that high priority applicationshave greater impacts on the performance of the network and hence performs better when itcomes to delay and throughput requirements. Even when the number of high priority applicationswere reduced, the results obtained was still able to satisfy QoS requirements for each traffic type.Results for different scenarios were taken and discussed. Also, differentiated values of delay,throughput and packet loss were recorded when same and different values of MAC and trafficgeneration parameters were used. In all results the International Telecommunications Union (ITU-T) values of these metrics parameters were kept low. These make the network design suitable forroad safety application where very low delay is required for emergency messages and tolerabledelay in routine messages. The results obtained show th at, this network can be applicable inroad safety, simply because of the low delay, and low loss which implies , messages to cars canbe successfully delivered and also good throughput. 802.11 legacy standard lacks servicedifferentiation that limits QoS support for real-time applications. These simulations were able tohandle the drawback associated with this standard and prefer a better standard which is 802.l i ethat provides differentiated access to the metrics that was used in analyzing QoS in this research
Adaptive data transfer for dedicated short range communications (DSRC)-based vehicle networks.
No full textACARS:Adaptive context - Aware rate selection for DSRC in vehicular networks
No full textThroughput plays a vital role for data transfer in Vehicular Networks which is useful for both safety and non-safety applications. An algorithm that adapts to mobile environment by using Context information has been proposed in this paper. Since one of the problems of existing rate adaptation algorithm is underutilization of link capacity in Vehicular environments, we have demonstrated that in wireless and mobile environments, vehicles can adapt to high mobility link condition and still perform better due to regular vehicles that will be out of communication range due to range checking and then de-congest the network thereby making the system perform better since fewer vehicles will contend for network resources. In this paper, we have design, implement and analyze ACARS, a more robust algorithm with significant increase in throughput performance and energy efficiency in the mist of high mobility of vehicles.</p
Using Derived Mobility Model Metrics to Evaluate the Impact of Transmission Range in Vehicular Networks
No full textEfficient RFID Modulation Scheme for Better Ubiquitous Network Performance
No full textThis paper presents an ongoing investigation into the effect of modulation schemes on Radio Frequency Identification performance and forecast the implication for a ubiquitous network such as the future Internet of Things. The paper plans to employ the use of two popular metrics – Bit Error Ratio and Signal-to-Noise Ratio to evaluate the success rate of the digital data transmission in RFID. The best modulation technique to achieve the best data transmission rates between readers and tags at an optimum power level would be established. It is hoped that the research results when completed would enhance the performance index of the future ubiquitous network
End to End Wireless Multimedia Service Modelling over a Metropolitan Area Network
No full textMultimedia applications have been the key driving force in converging fixed, mobile and IP networks. A major hurdle in the realisation of this convergence is obtaining Quality of Service from a heterogeneous, best-effort service network. Interactive voice requires strict bounds on delay, jitter and packet losses, video adds significant bandwidth requirements to the network, while Internet only makes its best effort to deliver a packet. Hence, the end-to-end QoS management of heterogeneous networks supporting multimedia services is of paramount importance. This paper presents a performance study of multimedia applications over 802.11 networks within metropolitan area networking environment. Specifically, we study QoS performance of VoIP applications over 802.11, while sharing the network resources with HTTP and video applications. Using the OPNET simulator, we simulate a number of realistic application traffic scenarios and study the network performance by analysing QoS parameters including delay, jitter, MOS, and packet loss rati
Performance Analysis of Adaptive Rate Mechanism for IEEE 802.11p in DSRC for Road Safety Application in Vehicular Networks
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