无线自组织网基本性能的研究

Wireless ad hoc network is a flexible and self-autonomous networking architecture, where nodes transmit with each other freely via wireless links without any pre-existing infrastructure or centralized administration. As it has very low cost of establishment, is robust against single point of failures, and can be rapidly deployed and flexibly reconfigured, wireless ad hoc network holds great promise for lots of applications including disaster relief and emergency response, battlefield networks, vehicular ad hoc networks, daily pedestrian networks, etc., and thus becomes an indispensable component among the next generation networks. However, due to the important issues of random node mobility, wireless interferences, and channel complexities among unscheduled simultaneous transmissions, the traditional Shannon information theory failed to characterize the fundamental performances in wireless ad hoc networks. Consequently, the fundamental performance limits, like the per node throughput capacity, the delay performance region for any feasible input rate, the end-to-end packet delivery probability under any given packet lifetime, etc., remain unknown for wireless ad hoc networks.Towards this end, in the last decades researchers from among the whole world have been actively exploring such extremely challenging problems and trying to develop a Shannon limit-like network information theory, so as to determine the fundamental performance limits in wireless ad hoc networks. It is noticed that available works mainly focused on exploring the order sense network scaling laws and tell us little about the exact achievable throughput capacity or average delay. In practice, however, exact results of fundamental performance limits are of great interest for network designers. As motivated by such limitations of available studies and in order to take a further step ahead, in this research we aim to develop theoretical frameworks for obtaining closed-form results for all above important performance metrics under various scenarios, such as limited packet lifetime or constrained buffer space, allowing selfish node behaviors, heterogeneous or hybrid node settings, etc.It is expected that this research will contribute to the networking industry by providing an accurate characterization of the fundamental performance limits in wireless ad hoc networks under various important application scenarios, and also by laying the foundation for establishment of emerging ad hoc network information theory.

无线自组织网络具有广泛的应用前景，但是由于节点任意移动及无线信道干扰等客观因素，其基本性能指标如网络容量等目前仍然处于未知。现有工作主要描述网络容量、时延等随节点增加的变化趋势，无法准确反映具体场景下实际可达的基本性能指标，严重制约了无线自组织网络的普及和发展。本研究针对现有工作的这类局限性，开发封闭显式的理论模型，刻画并求解各种实际场景下的网络基本性能。具体研究内容包括网络建模并显式求解给定数据包生命期、给定节点存储空间、允许节点私自行为、广义混合异构自组织网络下，网络吞吐容量、时延性能区间、端到端数据包传送概率等基本性能指标。最后，搭建原型无线自组织网络，验证所开发的理论模型和显式结果。本项目的成功实施，可为未来无线自组织网的设计和优化提供必要的理论指导，并为以后网络信息理论的创建打下必要的基础。

无线自组织网络具有广泛的应用前景，但是由于节点任意移动及无线信道干扰等客观因素，其基本性能指标如网络容量等目前仍然处于未知。现有工作主要描述网络容量、时延等随节点增加的变化趋势，无法准确反映具体场景下实际可达的基本性能指标，严重制约了无线自组织网络的普及和发展。本课题针对现有工作的这类局限性，开发了一系列封闭显式的理论模型，刻画并求解了各种实际场景下的网络基本性能。具体研究成果包括对节点组团运动的分析、D2D设备间直连链路通信研究、物理层通信安全研究、多跳D2D通信研究等，解析上行链路和下行链路的中断概率以及平均速率，分析功率控制、多信道设置、异构基站、用户切换等因素对移动用户中断概率以及平均速率等QoS指标的影响，并确定最优的D2D频谱资源分配方案。本项目的相关研究成果，可为未来无线自组织网的设计和优化提供必要的理论指导，并为以后网络信息理论的创建打下必要的基础。