Impact Of Propagation Environment Research Articles

Impact of Propagation Environment on the Performance of Direction Oriented Forwarding through Minimum Number of Edge Nodes (DOF-MEN) Routing Protocol In Ad Hoc Networks

One sort of wireless ad-hoc network is called MANET (Mobile Ad-hoc Network), which is an autonomous network made up of wireless nodes and routers connected by wireless connections. Transmission of data in effective way is important. The DOF-MEN (Direction Oriented Forwarding through Minimum Number of Edge Nodes) protocol is the protocol which lessens the amount of messages for route discovery. It attempts to choose just single node as the next following hop. The node's address is added by the sender. Therefore, only the chosen node will receive and subsequently transmit the data. This protocol increases the throughput, Packet Delivery Ratio, and cuts down on the Routing Overhead. Several aspects affect the routing protocol's execution accuracy in mobile ad hoc networks (MANET). The propagation model is a crucial thing to be considered among many. MANET experiences an enormous loss in performance due to blockage between transmission devices and fluctuation in the receiver's signal intensity. Therefore, it's crucial to determine how Radio Propagation Model and study of performance of routing protocol in MANET. Here we do simulation and analysis using NS2 (Network Simulator 2). The outcome demonstrates that the MANET routing protocol's performance is more influenced by the propagation model.

On the Covariance Matrix and Diversity Performance Evaluation of Compact Multiport Antenna Systems

In this communication, we present a new electromagnetic methodology that determines the covariance matrix of compact multiport antenna (MPA) systems at the early design stage. Further insight into this field is provided, as contrary to existing methodologies, it rigorously relies on the reciprocity principle of MPA systems. Thus, the impact of propagation environment, termination conditions, and MPA radiation characteristics as independent factors affecting performance is physically incorporated. Provided the availability of mathematical expressions for the cumulative distribution function and probability density function of received signal-to-noise ratio (SNR), performance can then be analytically studied via the diversity antenna gain (DAG) in terms of: 1) SNR enhancement at a specific outage probability (OP) level (that is DAG-OP) and 2) average SNR reduction for achieving a specific average bit error rate (BER) (that is DAG-BER). Illustrative examples with performance evaluation of compact MPA systems are presented. The adopted diversity technique is the transmit antenna selection/maximal ratio combining, which is analytically studied employing realistic MPA systems for the first time. Comparisons with existing published results further demonstrate the validity and usefulness of the proposed methodology.

Impact of Propagation Environment on Energy-Efficient Relay Placement: Model and Performance Analysis

The performance of a relay-based cellular network is greatly affected by the relay location within a cell. Existing results for optimal relay placement do not reflect how the radio propagation environment and choice of the coding scheme can impact system performance. In this paper, we analyze the impact on relaying performance of node distances, relay height and line-of-sight conditions for both uplink and downlink transmissions, using several relay coding schemes. Our first objective is to propose a geometrical model for energy-efficient relay placement that requires only a small number of characteristic distances. Our second objective is to estimate the maximum cell coverage of a relay-aided cell given power constraints, and conversely, the averaged energy consumption given a cell radius. We show that the practical full decode-forward scheme performs close to the energy-optimized partial decode-forward scheme when the relay is ideally located. However, away from this optimum relay location, performance rapidly degrades and more advanced coding scheme, such as partial decode-forward, is needed to maintain good performance and allow more freedom in the relay placement. Finally, we define a trade-off between cell coverage and energy efficiency, and show that there exists a relay location for which increasing the cell coverage has a minimal impact on the average energy consumed per unit area.