Multipath aware Scheduling for High Reliability and Fault Tolerance in Low Power Industrial Networks

The Industrial Internet of Things is expected to enable the Industry 4.0 through the large deployment of low-
power devices. However, industrial applications require most of the time high reliability close to 100%, and
low end-to-end delays. Thus, most industrial wireless networks rely on a strict schedule of the transmissions
to avoid collisions, and implement frequency hopping to combat external interference. In multihop topologies,
the network has to decide both when the transmissions have to be scheduled, and which router can forward
the packets. To be fault-tolerant, multipath routing consists in exploiting several paths in parallel. We
exploit here a braided path routing structure, where each router has several possible next hops. Thus, we
can cope with any fault along the path, while still providing a remaining operational path. We propose
also a scheduling algorithm, where multiple transmitters are attached to a single cell, to the same receiver.
The schedule is constructed such that only one transmitter is active at a time, and is consequently collision-
free. Mutualizing the same cell for several transmitters reduces the energy consumption and increases the
network capacity.