TI中文支持网在上百个节点组网中，每个节点给中继发送信息；是如何实现通道空闲检测的，具体原理是什么。
YiKai Chen：
基本上就是打開RX看看目前通道有沒有信號，沒有的話代表通道空闲
Viki Shi：
According to the IEEE 802.15.4 protocol, the unslotted CSMA/CA algorithm is similar to the slotted CSMA/CA algorithm, besides that it is used in the non-Beacon-enabled mode. In the unslotted CSMA/CA, each time a device wishes to transmit data frames or MAC commands, it waits for a random period. If the channel is found to be idle (done by CCA mechanism), following the random back-off, the device transmits its data. If the channel is found to be busy following the random back-off, the device waits for another random period before trying to access the channel again. Acknowledgment frames are sent without using a CSMA-CA mechanism.
