传感器网络能量有效空中重编程协议研究

Once a wireless sensor network is set up, embedded nodes and the sensing system requires functional update and reprogramming.This proposal is based on state-of-the-art WSN reprogramming over the air protocols, initiates a novel cross-layer WSN reprogramming over the air protocol regarding MAC，routing and networking layers aiming at nodes and system engergy-efficiency.The study focuses on the research of IEEE 802.15.4 adaptive access mechanism, which can provide MAC layer adaptive optimal contention window algorithm considering competition and random access. Besides, it studys the best node degree selection strategy which can solve the distributed power control issues considering node transmission power. Ultimately, The study assemblages channel access, power control and topology control in one set, builds up a system simulation platform and tests reprogramming over the air algorithms using TinyOS platform. The optimised protocols reduce the collide probability during accessing, attain relatively high throughput capacity and also reduces node energy loss to boost the energy efficiency. The study seeks for new breakthroughs and innovations on key technologies in WSN reprogramming over the air protocol regarding aspects such as channel access and power control, which will also establish new patents and intellectual property right.

无线传感器网络一旦部署，需通过有效方式对节点及传感系统进行更新与功能改造。课题针对现有空中重编程协议进展，以传感器节点能量有效为目标，提出基于MAC层、网络层与传输层的跨层无线空中重编程协议。课题主要研究IEEE 802.15.4自适应接入机制，解决基于竞争与随机访问的MAC层自适应最优竞争窗口算法；研究节点最优节点度选择策略，解决基于节点发射功率的分布式功率控制算法；最终集信道接入、功率控制与拓扑控制于一体，构建系统仿真平台和实际测试平台。课题目标提出优化协议，最大限度的减少接入碰撞概率并获得较高的吞吐量，同时减少节点能量损耗，打破传感节点程序低效更新僵局，在无线传感器网络空中重编程协议关键技术的信道接入、功率控制等方面寻求突破与创新，形成具有自主创新的知识产权与专利。

经过四年来对“传感器网络能量有效空中重编程协议研究”课题的研究，及工程的应用。从理论上来看该研究对已部署传感器网络的能量优化、节点生存期、网络升级等问题有一定的独特之处。针对现有空中重编程协议进展，以传感器节点能量有效为目标，提出基于MAC层、路由层与网络层的跨层无线空中重编程协议。课题主要研究IEEE 802.15.4自适应接入机制，解决基于竞争与随机访问的MAC层自适应最优竞争窗口算法；研究节点最优节点度选择策略，解决基于节点发射功率的分布式功率控制算法；最终集信道接入、功率控制与拓扑控制于一体，构建系统仿真平台和实际测试平台。设计并实现了基于信道接入机制下的自适应最优竞争窗口选择算法。利用空闲概率模型、成功传输时间、持续碰撞时间来获得网络时延模型，基于网络时延模型和CW窗口值得出最优CWI参数。根据空闲时槽间隔和三个门限参数值推导出节点数目估计。实现分布式传输功率控制算法，归纳并成功建立联合分布式传输功率控制和路由选择之间的关系。由节点密度、节点度和M度节点之间的百分比关系推导出最小节点度算法，结合剩余能量检测和网络负载分布建立最优路由选择。建立无线传感器网络的OMNET++仿真平台和TinyOS实验系统，把验证后的技术实用化拓展，实现优化的WSN空中编程协议实际应用，从而使本课题的研究成果有宽广的应用前景，可在无人值守的地区大范围推广。