面向低功耗无线网络无协调并发介质访问关键技术研究

This program proposes a generic concurrent low power listening mechanism supporting concurrent and conflict-free data transmission service for multiple senders. The basic idea is that rather than continuously and repeatedly transmitting the same data frame, a sender completes a data transmission by periodically alternating a data frame and a series of intentionally constructed wakeup preamble frames. The series of wakeup preamble frames are designed to rendezvous with receiver’s waking moment and transmitted by setting a well-designed low output power so that they won’t interfere neighbors’ data frame transmission. On that basis, as new sender, if the captured channel state indicates the channel is free or only used for the transmission of wakeup preamble frames, it immediately schedules data frame transmission over the free channel or overlapping with the identified wakeup preamble signals, rather than repeating the same carrier sense-defer process. In this way, this program can easily realize concurrent data transmission for multiple neighboring senders without compensating with any other performance indicators.

本项目通过设计唤醒前导帧机制向接收节点预约数据转发服务，也为载波侦听范围内的其它发送节点提供了及时有效的信道传输状况反馈机制，研究适用于低功耗节点的实时信道状态检测方法和信道访问可行性评估策略，最终实现低功耗无线网络无协调并发介质访问控制，解决现有低功耗无线网络信道访问效率低的问题，并进一步结合数据传输协议相关性能的优化方法，从根本上解决现有低功耗无线网络数据传输协议的性能瓶颈，实现低功耗无线网络无调度并发传输的目标。

本项目设计了一个通用的并发低功率监听机制，支持多个发送者的并发和无冲突的数据传输服务。其基本思想是，发送者不是连续重复地传输相同的数据帧，而是通过周期性地交替传输一个数据帧和一系列有意构建的唤醒序言帧来完成数据传输。这一系列唤醒前导帧被设计成与接收方的唤醒时刻相吻合，并通过设置一个精心设计的低输出功率来传输，这样它们就不会干扰邻居的数据帧传输。在此基础上，作为新的发送方，如果捕获的信道状态表明信道是空闲的或只用于传输唤醒前导帧，它就会立即安排数据帧在空闲的信道上传输或与已确定的唤醒前导信号重叠，而不是重复相同的载波感知-defer过程。这样，这个程序可以很容易地实现多个相邻发送者的并发数据传输，而不需要用其他性能指标进行补偿。本项目实现了低功耗无线网络无协调并发介质访问控制，解决了现有低功耗无线网络信道访问效率低的问题，并进一步结合数据传输协议相关性能的优化方法，解决了现有低功耗无线网络数据传输协议的性能瓶颈，达到了低功耗无线网络中无调度并发传输的研究目标。