| In this thesis, we consider the wireless transmission issues of ad-hoc and sensor networks. In fact, ad-hoc networks can be operated without infrastructure with capabilities to handle the terminal (node) mobility. Besides, they possess a property of a dynamic network topology. These properties enabled the ad-hoc networks to be used in several critical applications such as disaster-relief operations and military law enforcement. In other hands, sensor networks are characterized by tiny, inexpensive, and advanced communication technology. However, wireless ad-hoc and sensor networks (WASNs) have some issues such as the limited amount of energy, multipath fading, and some other issues when they applied in disaster situations.We address four categories in these issues as follows:1. Reduce power consumption in wireless ad-hoc and sensor networks.2. Combat the multipath fading effect with low complex.3. Mitigate the congestion in wireless ad-hoc networks.4. Manage the ICT Issues in Disaster Situation.Our contributions deal with all these issues. For reducing power consumption, we show mathematical analysis of energy saving, and enhanced error symbol probability. The simulation results prove our analysis. As for the multipath fading, we also show the mathematical analysis of fading channel characteristics and channel model, as well as how to mitigate the multipath fading by modulation and diversity techniques. From the simulation results, we prove the proposed system with amplify-and-forward (AF) relaying can achieve a2.5dB performance gain at the BER10-4, whereas the achievable improvement is almost a4dB at the BER of10-5when using maximal ratio combining.Furthermore, the research continued the mathematical analysis on channel model, first it introduce the basic of decode-and-forward (DF) relaying, analysis AWGN, and considering Rayleigh fading situation. Besides, the combining without diversity and combining with diversity in DF. For both cases, the outage probability is analyzed as well as the optimal power allocation between source and relay is also derived under different assumptions on the channel state information (CSI)Moreover, we propose a collision avoidance framework. This framework has several stages that are designed to enhance the performance over wireless sensor networks. Furthermore, to achieve the goal of optimal distribution a self-organized WASN is simulated. This network consists of several terminals that organize themselves repeatedly to form the network. In a disaster situation, several nodes send messages via the intermediate node, so that the congestion will occur. To address this problem, a cross layer scheme for predicting source transmission’s rate is proposed. The proposed rate makes balance between the packet arrival rate and the packet service rate to be suitable for both sender and receiver. We proved the proposed scheme with analysis and simulation, which showed that it can help to avoid congestion and enhancing the response time. Furthermore, a wearable smart sensor system is proposed. This system has a capability to extract the abnormal vital sign to decrease the overhead in the aggregator. This process can lower the power consumption by sending only the abnormal vital sign.ICT can play a key role in all stages of the disaster management, such as disaster prevention, alleviation and administration when the networks infrastructures are disabled. In this thesis, we design disaster Information and communication framework that has the ability to manage all disaster events with collaboration with all disaster authorities. Besides, we propose solutions for ICT issues in disaster situations. Also, this thesis handle disaster management framework with different analysis and plan systems as a solution to different issues with analysis. At the same time, this system can be used for managing disaster and reduce it effects. Moreover, we pick up the most significant disasters issues and use ICT as solutions for them. |
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