Performance analysis of optimal schedulers in single channel dense radio frequency identification environments

Javier Vales-Alonso,Francisco Javier Parrado-García,Juan J Alcaraz

doi:10.1186/1687-3963-2013-11

Javier Vales-Alonso, Francisco Javier Parrado-García + Show 1 more

Open Access

https://doi.org/10.1186/1687-3963-2013-11

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Abstract

Schedulers in radio frequency identification dense environments aim at distributing optimally a set of t slots between a group of m readers. In single-channel environments, the readers within mutual interference range must transmit at different times; otherwise, interferences prevent identification of the tags. The goal is to maximize the expected number of tags successfully identified within the t slots. This problem may be formulated as a mixed integer non-linear mathematical program, which may effectively exploit available knowledge about the number of competing tags in the reading zone of each reader. In this paper, we present this optimization problem and analyze the impact of tag estimation in the performance achieved by the scheduler. The results demonstrate that optimal solutions outperform a reference scheduler based on dividing the available slots proportionally to the number of tags in each reader. In addition, depending on the scenario load, the results reveal that there exist an optimum number of readers for the topology considered, since the total average number of identifications depend non-linearly on the load. Finally, we study the effect of imperfect tag population knowledge on the performance achieved by the readers.

Highlights

Passive radio frequency identification (RFID) is increasingly being used to identify and trace objects in supply chains, in manufacturing process, and so forth
A full-mesh topology of m readers has been selected. It is a typical configuration in facilities, since the reader interferences (RRI) distance is large as discussed in the introduction
The star topology of m readers selected for scenario two represents another practical case, where readers are confined to some areas, and interferences are restricted to some particular pairs, exclusively between R1 and the other readers in this example

Summary

Introduction

Passive radio frequency identification (RFID) is increasingly being used to identify and trace objects in supply chains, in manufacturing process, and so forth. We analyze the improvement obtained when this information is available and the effect on the expected performance when errors occur in tag estimation This resource allocation problem is addressed both for static and dynamic frame length identification procedures (which are described later in Section 2.1) and that the tags remain in coverage of their corresponding reader at least during the whole period of identification (t time-slots). Summarizing, to the best of our knowledge, all previous optimization models ignore the availability of information about the number of tags within the range of each reader This information can be very effectively exploited to construct a scheduler with the goal of maximizing the number of identifications in the interrogation period. Since the dynamic-FSA operation is used (see Section 2.1), the reader seeks to maximize reading throughput and allocates the optimal number of slots in each frame.

Results

Numerical examples

Conclusions