Abstract: In WiMAX networks, the biggest challenge is to overcome the effects of fading especially when nodes are mobile. The multipath nature of channel leads to ISI (Inter Symbol Interference) and the severity of ISI effects increases with bandwidth increase and this might get worse when nodes are moving . The radio link between the Base Station and Service Station/Mobile Station can be a LOS or it can be a NLOS. The environmental objects and features like buildings, weather conditions can severely obstruct NLOS signal. In this paper the effect of pedestrian multipath and node mobility in WiMAX network is studied under different codecs schemes in order to evaluate the effect of multipath channel fading when nodes are moving on the QoS parameters end to end delay, jitter, mean opinion score and throughput of a VoIP application. The obtained results showed that multipath fading with mobile nodes has sever effect on throughput and MOS value for all studied codecs and on the other parameters the effect varies depending on the implemented codecs. arabic 14 English 71
N. Aboalgasm, I. Almerhag , A. Daeri(3-2018)

This paper describes the place of MPLS in current state-of-the-art networking as a quality of service means through performing performance analysis of VoIP and video conferencing applications by comparing the effect of different protocols (OSPF, IS-IS, EIRGP) and the effect of various queuing techniques (PQ, WFQ, MWRR) in order to find the good combination of MPLS, routing, and queuing type that provides efficient suitable quality of service levels. The obtained results illustrate a competent combination of MPLS with queuing discipline, and routing could be achieved for each application, such as MPLS and EIGRP with WFQ queuing is an efficient arrangement for video conferencing application
Azeddien M. Sllame, Reema A. Saad, Mariam Abojella Msaad(5-2021)

Even though it is an essential requirement of any computer system, there is not yet a standard method to measure data security, especially when sending information over a network. However, the most common technique used to achieve the three goals of security is encryption. Three security metrics are derived from important issues of network security in this chapter. Each metric demonstrates the level of achievement in preserving one of the security goals. Routing algorithms based on these metrics are implemented to test the proposed solution. Computational effort and blocking probability are used to assess the behavior and the performance of these routing algorithms. Results show that the algorithms are able to find feasible paths between communicating parties and make reasonable savings in the computational effort needed to find an acceptable path. Consequently, higher blocking probabilities are encountered, which is the price to be paid for such savings. arabic 3 English 22
Ibrahim Almerhag(3-2014)