一种基于跳频预约模式的RFID读写器网络MAC协议

在大量RFID读写器应用场合,会产生读写器冲突问题,从而影响整个系统的读取率.为了解决读写器冲突问题,提出了一个建立在慢跳频扩频(FHSS)上的MAC协议.该协议采用阅读器同步机制,读写器首先通过不同的时隙竞争预约信道,成功后使用与该时隙对应的频率进行通信,并通知相邻读写器,避免了相邻读写器同时与同一个标签通信,避免了读写器-标签冲突;采用读写器通信和标签通信按频谱分开的机制,使得读写器和标签之间不会产生频率冲突;采用多个频率跳频机制,避免了读写器频率冲突.对该协议进行的分析表明,在读写器负载较大及读写器平均通信时间较长时,该协议的系统输出较高.

New MAC Protocol Based on Frequency Hop-reservation for RFID Reader Networks

The RFID reader collision problem emerges in the large applications; it will decrease the read rate of the whole system A MAC protocol based on the slow frequency hopping spread spectrum (FHSS) was proposed to resolve the reader collision problem.This MAC used reader synchronization mechanism. The reader used the corresponding frequency to communicate with tags if the reader competed with others and reserved the time slot successfully, and informed the neighbor readers to avoid communicating with tag simultaneously, thus prevented the tag interference. This MAC adopted the mechanism that reader transmissions and tag transmissions arc on separate frequency channels and the muti-frenquency hopping, so tags collide with tags but not with readers and readers collide with readers but not with tags, and such separation solves the reader frequency interference. The analysis results of the algorithm show that when the reader load is bigger and the reader average correspondence time is longer, the system throughput is higher.