Implementation of mobile sensing platform with a tree based sensor network

Abstract

This paper develops a new mobile sensing platform employing a tree based sensor network. The mobile sensing platform consists of mobile sensor devices, relay devices, and a sink device. We assume that robots, UAVs, etc. carry a mobile sensor device to measure environment. Therefore, the mobile sensor device can be easily relocated and can perform sensing at any locations. The relay devices can construct a tree based route to the sink device. Functions of the relay devices are data collection from the mobile sensor devices and data forwarding to the sink device. They also implement our special routing protocol and a media access control mechanism to avoid interference of radio signals in a sensor network and to reduce power consumption. We have developed special software for wireless module System on Chip (SoC) for IEEE 802.15.4 because our research target is to design a feasible and reasonable sensor network system. The consumed power of the SoC is 15mA in a transmission, 17mA in a reception, and 6μA in a sleep mode. Therefore, our mobile sensing platform can work with a solar cell and a Li-Po battery. The evaluation results show that our protocol can synchronize timing among relay devices, and can create a tree based route to a sink device. Additionally, they can find that mobile sensor devices can inform measured data to a sink device through relay devices.