The impact of propagation environment and traffic load on the performance of routing protocols in ad hoc networks

Wireless networks are characterized by a dynamic topology triggered by the nodes mobility. Thus, the wireless multi-hops connection and the channel do not have a determinist behaviour such as: interference or multiple paths. Moreover, the nodes' invisibility makes the wireless channel difficult to detect. This wireless networks' behaviour should be scrutinized. In our study, we mainly focus on radio propagation models by observing the evolution of the routing layer's performances in terms of the characteristics of the physical layer. For this purpose, we first examine and then display the simulation findings of the impact of different radio propagation models on the performance of ad hoc networks. To fully understand how these various radio models influence the networks performance, we have compared the performances of several routing protocols (DSR, AODV, and DSDV) for each propagation model. To complete our study, a comparison of energy performance based routing protocols and propagation models are presented. In order to reach credible results, we focused on the notion of nodes' speed and the number of connections by using the well known network simulator NS-2.Comment: 13 pages, 5 figures, International Journal of Distributed and Parallel Systems (IJDPS) Vol.3, No.1, January 201

A New Scheme of Group-based AKA for Machine Type Communication over LTE Networks

Machine Type Communication (MTC) is considered as one of the most important approaches to the future of mobile communication has attracted more and more attention. To reach the safety of MTC, applications in networks must meet the low power consumption requirements of devices and mass transmission device. When a large number of MTC devices get connected to the network, each MTC device must implement an independent access authentication process according to the 3GPP standard, which will cause serious traffic congestion in the Long Term Evolution (LTE) network. In this article, we propose a new group access authentication scheme, by which a huge number of MTC devices can be simultaneously authenticated by the network and establish an independent session key with the network respectively. Experimental results show that the proposed scheme can achieve robust security and avoid signaling overload on LTE network