TDMA implementation for simultaneous signal acquisition of machine condition in wireless sensor networks

Abstract

Wireless sensors, installed on machinery, and Time Division Multiple Access (TDMA) transmission make an ideal system for monitoring machine conditions in industrial plants because there is no need for electronic wiring. However, field application of such a system, capable of continuously transmitting data over 100 Hz sample rates, has not been successful so far. In this research, a TDMA network protocol capable of acquiring data from multiple sensors with over 100 Hz sample rates was developed for field application. The protocol was implemented in a single cluster-star topology network and the system was evaluated by node number and transmission distance. The network simulator-2 (ns-2) is used for real field simulation. The cases of non-TDMA and TDMA protocol are compared with four sensor nodes. In the case of a 20-second transmission time, there is little difference between the reception rates of non-TDMA and those of TDMA system. However, the difference was much greater when using a 60-second transmission time.