Performance Analysis of STDMA and RA-TDMA Wireless Protocols in Industrial Scenarios

Industrial applications in the industry 4.0 scope present significant requirements and challenges from the communication technologies perspective: low latency, reliability, and determinism. However, some use cases add requirements on mobility, scalability and openness, such as flexible and large automated warehouses and production lines. Combining these two kinds of requirements calls for wireless technologies that can provide an adequate trade-off. This paper compares two protocols that rate particularly well in such trade-off, namely Self-Organizing Time Division Multiple Access (STDMA) and Reconfigurable and Adaptive Time Division Multiple Access (RATDMA). The comparison was carried out through simulations under a multipath dispersed time-variant industrial channel while subject to a variable Doppler shift. To this end, we used OMNeT++ in combination with the VEINS framework to evaluate several relevant metrics such as packet losses and packet inter-arrival time. Overall, RA-TDMA shows longer disconnections caused by the hand-over between separate networks. Concerning packet losses, the protocols perform similarly, with RA-TDMA outperforming STDMA under overlapping networks or poor clock synchronization.