Efficient Polling-Based Information Collection in RFID Systems
Efficient Polling-Based Information Collection in RFID Systems
复制标题
RFID 系统中基于轮询的高效信息收集
DOI：
10.1109/tnet.2019.2906802
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Nie Changhai
中科院分区：
文献类型：
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作者：
Liu Jia;Xiao Bin;Liu Xuan;Bu Kai;Chen Lijun;Nie Changhai
RFID标签已被广泛应用于报告有关被标记物体或周围环境的有价值的信息。要收集这样的信息，关键是要避免开放无线信道中的标签对标签冲突。轮询作为一种广泛使用的防冲突协议，提供了一种查询标签的请求-响应方式。然而，基本轮询需要广播繁琐的标签ID(96位)来查询标签，这是耗时的。例如，仅收集1比特的信息(例如电池状态)，但具有96比特的开销是一个很大的限制。本文研究了如何设计高效的轮询协议来快速收集标签信息。其基本思想是最小化轮询向量的长度，同时避免无用的通信。我们首先提出了一种高效的哈希轮询协议(HPP)，该协议使用哈希索引而不是标签ID作为轮询向量来查询每个标签。轮询向量的长度从96比特下降到不超过16比特(标签数量小于100,000)。然后，我们提出了一种基于树的轮询协议(TPP)来避免HPP中的冗余传输。通过构建二叉轮询树，TPP只传输邻居轮询向量的不同后缀；相同的前缀被保留而不进行任何重传。结果是轮询向量的长度减少到仅3.4比特。最后，我们提出了一种增量轮询协议(IPP)，该协议根据当前轮询向量与前一个轮询向量之间的差值来更新轮询向量。通过对索引进行排序和动态更新，IPP将轮询向量降至1.6位长，比96位ID少60倍。大量的仿真结果表明，我们最好的协议IPP的性能优于最先进的信息收集协议。
RFID tags have been widely deployed to report valuable information about tagged objects or surrounding environment. To collect such information, the key is to avoid the tag-to-tag collision in the open wireless channel. Polling, as a widely used anti-collision protocol, provides a request-response way to interrogate tags. The basic polling however needs to broadcast the tedious tag ID (96 bits) to query a tag, which is time-consuming. For example, collecting only 1-bit information (e.g., battery status) but with 96-bit overhead is a great limitation. This paper studies how to design efficient polling protocols to collect tag information quickly. The basic idea is to minimize the length of the polling vector as well as to avoid useless communication. We first propose an efficient Hash polling protocol (HPP) that uses hash indices rather than tag IDs as the polling vector to query each tag. The length of the polling vector is dropped from 96 bits to no more than 16 bits (the number of tags is less than 100,000). We then propose a tree-based polling protocol (TPP) that avoids redundant transmission in HPP. By constructing a binary polling tree, TPP transmits only different postfix of the neighbor polling vectors; the same prefix is reserved without any retransmission. The result is that the length of the polling vector reduces to only 3.4 bits. Finally, we propose an incremental polling protocol (IPP) that updates the polling vector based on the difference in value between the current polling vector and the previous one. By sorting the indices and dynamically updating them, IPP drops the polling vector to 1.6 bits long, 60 times less than 96-bit IDs. Extensive simulation results show that our best protocol IPP outperforms the state-of-the-art information collection protocol.