Radio Frequency/Free Space Optical and Radio Frequency-only Wireless Sensor Networks: A Comparative Study of Performance

Abstract

Wireless sensor networks (WSNs) consist of networked sensor nodes, deployed to sense a phenomenon and report it to a base station. Sensor nodes are small and usually equipped with small batteries with limited capacity, and therefore, one of the most important design considerations for WSNs is power consumption. WSNs expend energy for communications, data processing and sensing; for commonly used RF communications this task accounts for the largest portion of power expended. Hybrid radio frequency/free space optical (RF/FSO) communications has been proposed to reduce power consumption by the sensor node, and in this paper, the performance of the RF/FSO WSN is compared against an RF-only WSN in terms of network lifetime and coverage. Results show that for the wide range of scenarios considered, the RF/FSO WSN lasts at least twice as long as its RF-only counterpart, despite providing the same level of network coverage. This paper also investigates network parameter selection for optimum RF/FSO network coverage.

Keywords:

• Free space optics
• Network architectures
• protocols
• Sensor networks

Additional information

Notes on contributors

Sashigaran Sivathasan

Sashigaran Sivathasan received his MSc (2001) and DPhil (2008) degrees from the University of London (Imperial College London) and the University of Oxford respectively. He is a Senior Lecturer at Curtin University of Technology (Sarawak Campus, Malaysia). His current research is in the area of wireless sensor networks. E-mail: [email protected]

Dominic O’Brien

Dominic O’Brien received his MA (1991) amd PhD (1993) degrees from the Department of Engineering at the University of Cambridge. From 1993–1995 he was a NATO fellow at the Optoelectronic Computing Systems Center at the University of Colorado. His current research is in the field of optical wireless systems. He is the author or co-author of approximately 130 publications or patents in the area of optics and optoelectronics. He is a Reader in Engineering Science at the University of Oxford, and leads the optical wireless communications group. E-mail: [email protected]