摘要
为减少重复识别标签的时间,在动态帧时隙Aloha的RFID标签防冲突协议的基础上提出了一种自适应的动态帧时隙Aloha(adaptive dynamic framed Aloha,ADFA)的防冲突协议.在ADFA协议中,阅读器每成功识别一个标签就自适应地给该标签分配一个时隙号,该时隙号规定了标签在一次识别过程中被阅读器识别的顺序,若当前识别过程中待识别的标签与上一次识别过程中的标签相比有较多的重复,ADFA协议就可以减少冲突和空时隙,从而减少标签识别时间.另外,为进一步减少ADFA协议识别标签的时间,还对其作了改进,在改进的ADFA协议中,提出了一种低复杂度标签估计和最优帧长方案.理论分析和仿真结果均表明,ADFA协议在重复识别标签时能够减少识别时间,改进ADFA协议的标签估计方法能够减少计算复杂度,而其最优帧长方案能使系统的吞吐量得到提高.
When a radio frequency identification（RFID） system identifies multiple tags,tag collisions will happen.The RFID system generally applies a tag anti-collision protocol to resolve the multi-tag collisions.To reduce identified time,this paper proposes a new adaptive dynamic framed Aloha（ADFA） for RFID tag collision arbitration.Based on dynamic framed Aloha protocol,ADFA adaptively allocates each identified tag a slot number.During the next reading round,the tags will be identified according to the slot number,which can reduce collision and idle slots when a reader repeatedly tags.In many RFID applications where a reader may repeatedly identify tags,such as supply chain operation,object tracking and locating,the proposed protocols can reduce time of re-identifying tags.Furthermore,to reduce more identified time,we improve ADFA protocol and propose a tag quantity estimate with low computational complexity and an optimal frame length.The tag estimate is based on Vogt method,and can reduce computational complexity by narrowing the search range of the tag quantity.And the optimal frame length scheme can achieve maximum throughput under the condition that the slot durations are different.The theoretical computation and simulation results both show that ADFA can reduce identified time when repeatedly reading tags,and the tag estimate in the improved ADFA can lower computational complexity.In addition,the optimal frame length in the improved ADFA can also advance system throughput.
出处
《计算机研究与发展》
EI
CSCD
北大核心
2011年第5期802-810,共9页
Journal of Computer Research and Development
基金
云南省教育厅科学研究基金项目(2010Y423)
