中文摘要：

文中采用低成本、低功耗STM8L151作为控制器,高性能、高集成度的射频芯片SI4432作为收发芯片。同时改进了冲突退避算法,考虑当前网络状态,引入概率机制合理选择随机退避时间区间,减少数据包碰撞几率,降低了丢包率。结合实际环境,兼顾接收信号强度指示器（RSSI）阈值与覆盖范围的大小,计算最优发射功率,降低功耗。

英文摘要：

In this paper,low-cost and low-power consumption STM8L151 was used as MCU,and high-performance and highintegrate SI4432 was used as transceiver. In order to decrease the data loss caused by data conflict,considering that the current network status and probability mechanism were introduced to reasonable change back off time interval,back off algorithm was improved. In order to reduce power consumption,the optimize transmission power was calculated following the RSSI threshold and the range of coverage in actual environment.