Wireless Network Coverage And Signal Blind Study

In recent years, with the rapid development of wireless communication technology, there is an urgent need for high-quality communication links, which can provide "Always Online" services besides high transmission rate, high-capacity and bandwidth multimedia services. It is limited signal coverage under the traditional cellular system that has become an unavoidable issue. Meanwhile, integration technology in heterogeneous wireless networks turns into effective method to solve the problem along with the growing development of cellular networks and Ad Hoc networks.This article in detail describes the problem of the dead spots coverage in heterogeneous networks making using of cellular network with multi-hop relaying assi stive technology based on the integration of cellular networks and Ad Hoc networks, at the same time, the types of relays under the heterogeneous network are summarized. This paper not only systematically introduces wireless channel model, such as path-loss model, shadow fading model and multi-path fading model which adopt in wireless cellular networks and Ad Hoc networks convergence and frequency reuse key technologies, but also indicates short comings in the process of solving the problem of dead spots coverage. Based on comparative study about a variety of relays assistive technologies, a dead spot coverage model applying to heterogeneous network is proposed, a measurement method which can test dead signal quality is put forward. This model not only reduces the call interrupt rate, but also enhances the effective area of cellular network coverage and quality of service.The research contents and main work of the paper are as follows:1. Research on multi-hop relay assistive technology of wireless networks. After analysis of its principle and characteristics in depth, this paper put forward to a model to solve dead spot signal coverage through setting a fixed relay combination with multi-hop Ad Hoc relays. The model analyzed numerically switching node distance, the signal switching time and relay selection algorithm of the node near the dead spot under the environment. Lastly, we used NS2 software to simulate the system model of Ad Hoc relay through one hop relays to fixed relay under signal dead spot coverage of cellular area. The experimental data shows that the model has greatly improved on the performance of cellular network coverage.2. Research on cellular networks and Ad Hoc network convergence in multi-hop path selection problem. Aiming at the problem of network congestion on the local area, insufficient channel and communication interruption due to the weak signal strength around dead spots, this paper proposed the scheme of a communication system architecture solution that combining mobile node with fixed relay to solve the dead spot coverage. The scheme gave set of fixed relay in the cell edge and transferred traffic to hot spot area with fixed relay and cluster heads of Ad Hoc network. The channel will be saved for the node in dead spot. Besides, it can broaden the range of high-speed with Multi-Hop relay in converged network and resolve the dead spot defects existing in wireless networks by using terminal self-organizing.