Abstract—4th generation networks postulate high speed ubiquitous coverage for all types of mobility which in turn demands seamless handover of connectivity from one network to another. This has necessitated a detailed performance study of handover among homogeneous and heterogeneous networks. This document summarizes our analysis of various types of handoffs among wireless networks. A detailed study of two poplar wireless access networks namely, WiMax(802.16) and WLAN(802.11) has been performed and the handover mechanisms among them have been studied. To this end, we have analyzed performance of two types of handoffs – horizontal handoff between two homogeneous networks (WLAN-WLAN or WiMax-WiMax) and vertical handoff between two heterogeneous networks (WLAN-WiMax). In order to study the performance of vertical handoff, IEEE 802.21 Media Independent Handover has been employed. Metrics like Average handoff distances for varying power threshold in layer 2 and 3 and packet drop rate for varying speed have been studied and conclusions have been drawn for different scenarios.
Keywords: IEEE802.11e, IEEE802.16, IEEE802.21 Media Independent Handover,Intersystem Handover.
Abstract—Security forms an important part of wireless network communication system. A variety of attacks can be performed on 802.11 MAC thereby compromising the security of the system and also leading to degradation of the system performance. The security attacks can be classified into different categories based on criteria nature of the attack, domain or attack techniques used. In this work we study the performance of IEEE 802.11 MAC with CSMA/CA systems under various jamming attacks. The study will comprise of simulation of jamming attacks and its effect on various system parameters like throughput, latency, offered load, etc.
Keywords—802.11 DCF, 802.11 EDCA, Jamming attacks.