Keywords : QoS


A Proposed Model for the Mutual Dependency Between QoE and QoS in Wireless Heterogeneous Networks

Hasan F. Khazaal; Rawaa I. Farhan; Baraa I. Farhan; Haider Th. Salim ALRikabi; Stavros Kotsopoulos; Stavros Kotsopoulos

Journal of Al-Qadisiyah for Computer Science and Mathematics, 2017, Volume 9, Issue 2, Pages 45-55

Streaming of video over wireless heterogeneous networks coping with the problem of packet loss which affects the perceived video quality. The service providers usually use the Peak Signal to Noise Ratio PSNR as a metric measure for the quality of their provided service. So they use the quality of service QoS of the network as a sign on the quality of their presented service. The QoS deal with the objective tests of the provided service, which mean the measure of PSNR of the presented objects. The presented objects may not get the satisfaction of the network users due to many factors although that the PSNR of the used service is enough for presenting the service. Recently the service providers use the Quality of Experience QoE term which deal with the subjective test of the presented object (i.e. the user satisfaction measure). In this paper we propose a new model to identify the importance or the significance of the role of the QoE assessment for the service providers. To verify our proposed model we did a referendum for 55 participants in order to assess their judgment on the quality of some presented videos. The results of the referendum match the consideration of the proposed model.

A Simulation of a Networked Video Monitoring System Using NS2

Muntasir Jaber Jawad Al-Asfoor

Journal of Al-Qadisiyah for Computer Science and Mathematics, 2017, Volume 9, Issue 1, Pages 117-131

The work presented in this paper has focused on the simulation of video streaming over a hybrid (wired-wireless) network for the purpose of monitoring. A simulation scenario has been designed and implemented using the network simulator (NS2) to realise the network system. The system consists of 5 nodes, 3 of which are video cameras that play two major roles. First of all, capturing moving objects within a radius of 20 metres and secondly to work as a wireless routers within the network. Furthermore, the two nodes have different purposes; the fourth node works as an access point to connect the cameras which are wirelessly connected together and with the access point. However, the fifth node performs the job of a server which is wired-connected to the access point and has the video encoding/decoding and quality of service (QoS) calculations routines.The system has been implemented and tested under simulation environment and two types of assessment have been performed. The first assessment was to measure the quality of service from a networking point of view for which three factors have been used; namely: Packet Loss, End-to-End Throughput and Jitter. The second assessment was to measure the quality of the received videos using Peak signal to Noise Ratio "PSNR" measure. For simulation purposes 3 videos of type H.264 have been used to represent the 3 cameras streams. Evalvid framework is used to transform them into a streaming format to facilitate the evaluation of video streaming over a simulated network. The simulation process has shown a promising results in both network's QoS and video quality with the average packet loss of 0.04%, average time delay of 0.9sec and average jitter of 0.001951. More after, the video quality has shown an average "PSNR" of 30.13 when 1530 frames have been transmitted with STDV of 6.85.