Extension of wireless sensor network by employing RoF-based 4G network

Sensor network based on Zigbee is the key technology in implementing ubiquitous City (u-City). However, if only wireless ad-hoc network is used in large sensor network such as u-City, it requires too many hops causing problems like address assignment and time delay. Above problems are solved when the u-City is divided into multiple clusters, which are then connected with the personal area network coordinator (PANC). The main objective of this paper is to find out possible ways to extend the wireless sensor network (WSN) using radio over fiber (RoF). A PANC is the focal point of a sensor network that receives signals from tree-type Zigbee nodes and transmits them to a control node.