In the recent years the development in communication systems has received considerable attention from the research community and this results the development of low cost, minimal weight, low profile antennas that are capable of maintaining high performance over a wide spectrum of frequencies. This technological trend has focused much effort into the design of a Micro strip patch antenna. In this Paper a design have been considered, results of this design have been compared with each other by using IE3D an electromagnetic simulation package previously by Zeland Software Inc presently by. Mentor Graphics Inc. and design parameters are calculated using MATLAB software. We compared the results of the design in the frequency band 2GHz to 3.5GHz and we will suggest the best configuration of antenna with suitable Return Loss (RL), VSWR, Bandwidth, Gain, 2D and 3D Radiation Pattern that can be used in practice for communication purpose specially for mobile communication.
A Mobile ad hoc network (MANET) is a self-configuring network of mobile devices connected by wireless links. The communication in ad hoc network is uncertain because established route could be broken anytime. There could occur a lot of delay between active route breakage & backup route discovery, causing the loss of a lot of data packets. In our proposed scheme (Reliable-AODV), we try to maximize the probability of finding a backup route before the active route breakage. Proposed scheme make use of two levels of threshold for each: node's Battery Power and Received Signal Power. A close analysis of the proposed scheme gives that it improves the packet delivery fraction and reduces end-to-end delay for data packets.
With the growing popularity of IEEE 802.11 WLAN Standards, securing authentication process between client, authenticator and authentication server has become of utmost importance. For securing the authentication process, Extensible Authentication Protocol (EAP) supports an open architecture allowing multiple EAP authentication methods to be used. EAP re-authentication protocol provides a consistent, method-independent and low-latency re-authentication mechanism for authentication in 802.11 wireless networks. Mechanisms of authentication usually exist above the physical layer. In few cases utilizing spread-spectrum technique, authentication process may exist at physical layer but incurring an additional cost on bandwidth. The present work aims to evaluate the performance of authentication protocols by comparing the security cost of EAP re-authentication protocol with EAP-TLS protocol at different processor speeds. We analyze a physical-layer authentication algorithm that utilizes channel probing and hypothesis testing to determine whether current and prior communication attempts are made by the same transmit terminal. We further report an enhanced physical-layer authentication scheme for multi-carrier wireless systems, which is capable of working with moderate terminal mobility. Numerical Results using simulation tool MATLAB in a typical indoor environments show that the scheme based on the Neyman-Pearson test is more robust against terminal mobility, and is able to detect spoofing attacks efficiently with small system overhead when the terminal moves with a normal pedestrian speed. The impact of system parameters on the performance has also been investigated.
