Wireless communications and a priority access protocol for multiple mobile terminals in factory automation

Considering the code division multiple access (CDMA) radio communication schemes, this paper proposes a wireless access infrastructure and a protocol for factory automation with several mobile terminals. A factory manufacturing floor usually forms several islands of automation with each having multiple mobile terminals. Each island of automation can be covered by a base station that then connects to a supervisory computer (command center). The base station can then serve as a bridge between the wireless network and the MAP backbone. Adding wireless access capability to a MAP-based network can release the problem of rewiring the moving devices in floor planning and restructuring. Considering a priority structure, we propose a Handshake-Aloha protocol suitable for such wireless factory environment. The numerical results show that it performs much better than the random access schemes such as Aloha protocol in terms of the throughput and delay performance.