Optimizing guard time for TDMA in a wireless sensor network - Case study

When the Time Division Multiple Access (TDMA) protocol is used to schedule communication over a shared medium in wireless sensor networks, clock drift can be tolerated using guard time. A guard time is a short time interval that is added between the TDMA slots. Using guard time requires extra time and energy, which is critical in wireless sensor networks operating on limited energy. In this case study, we apply a formal approach to compute optimal safe guard times, i.e. shortest guard times which avoid message collision and loss due to clock drift in a wireless sensor network. We show the flexibility of the formal approach and its usefulness under several real-world conditions.