针对低功率无线网络并发传输的干扰模型和协议研究

Recent years have witnessed the unprecedented proliferation of lower-power wireless networks (LWNs) such as 802.15.4-based personal area networks and wireless sensor networks. Although the LWNs are primarily designed for energy optimization, they are increasingly deployed for performance-sensitive applications which pose a major challenge for the communication performance of LWNs. Wireless interference is the main factor that influences the communication performance of LWNs. Several advances have been made for understanding the behavior of interference among low-power radios. However, they have not led to the performance improvement of LWNs in practice, largely due to two reasons: First, the interference models are not accurate or incur prohibitively high measurement overhead, thus the performance of upper layer protocols is limited. Second, the existing MAC protocols for LWNs are not designed to exploit the realities complex interference for transmission concurrency. Moreover, most of the existing concurrent transmission techniques are introduced by specific MACs, and cannot be used in general. In this project, we propose to develop concurrent LWNs by enabling potentially interfering wireless to communicate simultaneously. By means of accurate and lightweight interference modeling, the power/frequency adaptive concurrent transmission design under the unified framework, the communication performance of LWNs can get improvement. The result of this project can promote the extension of LWNs in performance-sensitive applications.

近年来，低功耗无线网络(LWNs)得到了空前发展，如基于802.15.4的个人区域网络和无线传感器网络，尽管LWNs设计之初主要考虑对能量进行优化，然而，LWNs正越来越多的用于性能敏感型应用而对通信性能提出了严峻挑战。无线干扰是影响LWNs通信性能的主要因素，虽然现有研究在理解干扰对低功耗无线信号的影响上有了一些进展，但在实际应用中并未导致LWNs性能有较大提高，这主要有两方面原因：首先，干扰模型不准确或测量代价过高，使上层协议的性能受限；其次，现有MAC协议在设计时没有考虑并发传输过程中的复杂干扰问题，且现有的并发传输技术大都由特定MAC协议引出，无法推广使用。本项目拟研究允许潜在干扰的无线信号同时传输的LWNs并发传输方案，通过准确的轻量级干扰测量建模，统一架构下的功率/频率自适应并发传输协议设计，使LWNs的通信性能得到提升。本项目的研究将有助于LWNs在性能敏感型应用中的推广。

本项目对低功耗无线网络进行了一系列的测量和传输方案设计工作。针对无线传感器网络通信性能低的问题，设计了基于相长干涉的并发传输方案，通过选择合理的并发节点组合，使得传输时延和传输能耗都得到优化，另外，还提出了一种可行的利用无人机对传感网数据进行收集的方案；针对窄带物联网运行期间的节点能耗、小区选择、随机接入等性能还不明确的问题，我们设计了软硬件测试平台进行了大规模的网络测试，发现了节点能量消耗严重不平衡的问题、ECL选择非优问题、小区选择频繁摆动问题等，针对这些问题，我们提出了一些可行的方案进行改进，并对所提方案的有效性进行了实验验证；设计了利用商用RFID无线信号进行持续呼吸量监测和木材种类识别的系统，两个系统都具有较高的准确率。本项目的研究有助于LWNs在物联网相关应用中的推广。