Long-range and energy-efficient optical networking for tiny sensors

Acquiring real time sensory data using remote swarms of tiny sensors depends on efficient wireless networking. Often, battery longevity of the sensors is a critical design requirement, which makes long-range RF transmission inadequate for this task. A common solution is to use short-range and energy-efficient RF protocols within the swarm, then communicate with the outside world via a capable agent or a networking gateway. In this paper we suggest an alternative networking model, which enables the swarm to operate independently, without the assistance of an intermediate proxy. Specifically, we present a networking model in which the sensors in the swarm transmit data using energy-efficient free space optical links (FSO). We discuss the details of aiming optical transmission interfaces in the directions of distant sinks, such as antenna towers, drones and even LEO-satellites. This FSO-based network architecture poses various data collection problems, which are related to the directional nature of optical transmitters and receivers. Using simulations we address several such problems, and demonstrate the viability of the model for sensory data collection.