Research on Autonomous Distributed Wireless Ad Hoc Networks

自主分布式无线自组织网络是由协作节点组成的自配置系统，无需任何已建立的基础设施。一个关键的假设是任何两个节点都可以直接通信或使用多跳中继。通过对物理层、媒体访问控制层、网络层等的关注，阐明了无线自组织网络的几个基本特性。主要研究成果总结如下：1。符号速率控制和多跳传输具有在损失吞吐量的情况下扩展业务区域的能力。数值结果表明，符号速率控制与多跳传输之间存在显著差异，只有多跳传输才能提高空间频谱效率。在分布式控制无线自组织网络中，由于相互干扰，每个节点都以自私的方式寻找吞吐量更好的路由，可能会在多条路由之间产生路由选择冲突。为了进一步分析这种行为，发现博弈论是有效的，并应用博弈论来评估可实现的吞吐量。结果表明，当发射功率较低时，分散自适应选路可以达到接近容量的吞吐量。CSMA/CA是广泛应用于自组织网络的媒体访问控制协议。为了满足提高网络吞吐量的需求，提出了多信道和信道绑定技术，以有效地利用现有的多个信道。数值和仿真结果表明，在低业务量条件下，信道绑定技术可以实现低延迟，而在高业务量条件下，多信道技术可以同时提高吞吐量和延迟。TCP被广泛认为是一种用于自组织网络的传输协议。然而，无线网络的链路质量不稳定可能导致效率低于有线网络。提出了一种利用误码包使龙卷风码对误码有效的新译码方法，并通过实验验证了该方法的优越性。少

Autonomous distributed wireless ad hoc networks are self-configuring systems formed by co-operating nodes without any established infrastructure. A key assumption is that any two nodes can communicate directly or using multi-hop relaying. By paying attention to multiple layers, i.e., physical, media access control, network, etc., several essential properties of wireless ad hoc networks are clarified. Major research results are summarized below.1.Symbol rate control and multi-hop transmission have the same ability to expand the service area at the loss of throughput. Numerical results revealed a significant difference between symbol rate control and multi-hop transmission such that only multi-hop transmission can increase the spatial spectral efficiency.2.In distributed control wireless ad hoc networks, there might occur conflicts in route selection among multiple routes if each node seeks for better route with better throughput in a selfish manner due to mutual interference. To analyze … More this behavior, game theory is found to be effective and is applied to evaluate the achievable throughput. It is revealed that when the transmit power is low, decentralized adaptive route selection may attain throughput near the capacity.3.CSMA/CA is widely used for media access control protocol of ad hoc networks. In order to meet the demand to increase the network throughput, multi-channel and channel bonding techniques are proposed to effectively utilize multiple existing channels. Numerical and simulation results indicate that under low-traffic conditions, channel-bonding technique can achieve a low delay, while under high-traffic conditions, the multi-channel technique improve both throughput and delay.4.TCP is widely considered to be a transport protocol for ad hoc networks. However, instable link quality of wireless networks may result in lower efficiency compared to wired networks. A new decoding method which makes Tornado-type codes effective to bit errors by exploiting error packets is proposed and the advantage of the proposed method is confirmed by experiments. Less