Feasibility and protocol for wireless communication of multiple mobile terminals in factory automation

This paper studies a CDMA wireless access infrastructure for a factory with several mobile terminals. Factory manufacturing floor usually forms several "islands of automation" with each having multiple mobile terminals. Each island of automation can then be covered by a base station which is attached to the supervisory computer (command center). Based on a priority structure, we propose a wireless access protocol and develop a mathematical model to evaluate its performance. The mathematical model uses several Markov chains which can model the dynamic behavior of the CDMA channel. The numerical results show that it performs much better than other random access schemes such as the Aloha protocol in terms of the packet lost rate and delay performance.