摘要
适合于RFID低成本要求的Aloha协议中存在标签无法被阅读器多次识别的饥饿现象.在移动RFID系统中,该现象将导致标签漏读这一严重问题,而有效地解决地这一问题需要大幅提高Aloha协议的识别效率.为此考虑RFID无线通信系统中客观存在的捕获效应,提出一种预约时隙分配高效防碰撞协议.该协议基于捕获效应将识别循环分为预约和在读取标签两个阶段,通过帧前预约机制和感知冲突机制有效地减少了读取阶段的无效时隙数.在此基础上,通过选择最优预约随机码位数和预约时隙数,实现了该防碰撞协议的识别效率最优化.此外还给出了适用于本协议的基于捕获效应标签数估计方法.性能评估表明该防碰撞协议的平均识别效率达到92.6%,明显高于现有Aloha协议,因而该协议比现有协议更适合于移动RFID系统.此外该协议在识别速度、通信复杂性和抗干扰能力方面明显优于现有的典型防碰撞协议.通过研制基于该协议的RFID原型系统,利用该系统完成的物理实验结果表明了协议的有效性.
For low cost Aloha protocols,there exists a hunger phenomenon that the reader cannot identify tags within limited times.This phenomenon will cause a serious problem that the reader misses tags in mobile RFID system.It is an effective solution to this problem to improve the identification efficiency of the Aloha protocols.Therefore,this paper proposes an efficient anti-collision protocol based on the reservation of slots allocation considering the capture effect of the RFID wireless communication system.In this protocol based on the capture effect,each identification round is divided into two steps including the reservation and the identification.As results of the reservation,it avoids collision frame slots by using the detection mechanism when reservation collisions occur and empty frame slots by using the reservations of frame slots before readers allocate the frame slots.Furthermore,the optimal bit number of reservation random code and the optimal number of reservation slot are given to achieve the optimal efficiency.In addition,the tag estimation method suitable for the protocol is also proposed considering the capture effect.Performance estimations show that the average efficiency of the protocol is about 92.6% and it significantly outperforms the existing anti-collision protocols in terms of identification speed,communication complexity and anti-interference.Therefore,the protocol is fitter for the mobile RFID systems than the existing protocols.The RFID prototype system adopting the proposed protocol was developed,and the results of the physics experiments based on the prototype system show that the protocol is effective.
出处
《计算机学报》
EI
CSCD
北大核心
2015年第12期2375-2389,共15页
Chinese Journal of Computers
基金
国家自然科学基金(61531016
61271090
61471306)
国家"八六三"高技术研究发展计划重大项目基金(2012AA012305)
四川省科技支撑计划项目(2012GZ0101
2014GZ0006)
成都市科技计划项目(2014-HM01-00144-SF
2014H056)
中央高校科研专项基金(2014NZYQN54)
四川省教育厅科技项目(14ZA0368)
国家民委科研项目(14XNZ022)资助
