Joint Optimization of Data Freshness and Fidelity for Selection Combining-Based Transmissions.

Zhengchuan Chen,Min Wang,Yunjian Jia,Mingjun Xu

doi:10.3390/e24020200

Abstract

Motivated by big data applications in the Internet of Things (IoT), abundant information arrives at the fusion center (FC) waiting to be processed. It is of great significance to ensure data freshness and fidelity simultaneously. We consider a wireless sensor network (WSN) where several sensor nodes observe one metric and then transmit the observations to the FC using a selection combining (SC) scheme. We adopt the age of information (AoI) and minimum mean square error (MMSE) metrics to measure the data freshness and fidelity, respectively. Explicit expressions of average AoI and MMSE are derived. After that, we jointly optimize the two metrics by adjusting the number of sensor nodes. A closed-form sub-optimal number of sensor nodes is proposed to achieve the best freshness and fidelity tradeoff with negligible errors. Numerical results show that using the proposed node number designs can effectively improve the freshness and fidelity of the transmitted data.

Highlights

Combining-Based Transmissions.With the emergence of the Internet of Things (IoT) and continuous development of communication techniques, increasingly more facilities are connected to the Internet.At the same time, a flood of information swarms into the fusion center (FC) waiting to be processed.Wireless sensor network (WSN) is a typical data-driven application in IoT, where multiple sensor nodes are deployed dispersedly aiming at observing the information source
Motivated by the opposite trend of two metrics affected by the number of sensor nodes, we aim to find the optimal number of sensor nodes by carefully characterizing the data freshness and fidelity using the age of information (AoI) and minimum mean square error (MMSE) metric
We investigate the effects of system parameters on the overall system freshness and fidelity

Summary

Introduction

Combining-Based Transmissions.With the emergence of the Internet of Things (IoT) and continuous development of communication techniques, increasingly more facilities are connected to the Internet.At the same time, a flood of information swarms into the fusion center (FC) waiting to be processed.Wireless sensor network (WSN) is a typical data-driven application in IoT, where multiple sensor nodes are deployed dispersedly aiming at observing the information source. With the emergence of the Internet of Things (IoT) and continuous development of communication techniques, increasingly more facilities are connected to the Internet. A flood of information swarms into the fusion center (FC) waiting to be processed. Wireless sensor network (WSN) is a typical data-driven application in IoT, where multiple sensor nodes are deployed dispersedly aiming at observing the information source. The observed information is transmitted through wireless channels, reaching the FC for further data gathering and recovery. Typical examples of WSN include forest salinity monitoring, smart parking, intelligent transportation safety supervising, and so on

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Conclusion