SAMPLER: An Optimal MAC Algorithm for Wireless Instrumentation Systems

Wireless devices provide flexible solutions for industrial instrumentation applications, such as quality control of manufacture of jet engines. In this context, the dominant issues are providing high-throughput, and reliability in the sense of not losing samples due to buffer overflow at the wireless devices. A random medium access control (MAC) scheme, such as the IEEE 802.15.4, is unlikely to perform well along those metrics. CSMA/CA, the foundation of IEEE 802.15.4, is inefficient at the high-throughput regime. The polling mode of IEEE 802.15.4, on the other hand, ignores the buffer constraints, thereby increasing the risk of buffer overflow. In this paper, we propose SAMPLER, a scheduled MAC protocol that is optimal, in the sense of minimizing sample losses while maximizing throughput, in the typical scenario where a sophisticated access point forms a star topology with the wireless sensors. We describe SAMPLER, its properties and demonstrate its superior performance compared to random-access MAC through simulations.