Modelling the behavior of a beacon-based link sensing mechanism with variable sensing range

The links in an ad hoc or wireless mesh network are normally kept alive by the exchange of beacon-messages between neighboring nodes. These beacons are prone to collisions with traffic from hidden nodes. If several beacons are lost due to overlapping transmissions, the node expecting the beacons erroneously assumes that the link is down. This is called an apparent link-failure. This paper provides an analytical model of apparent link-failures in a mesh network. The paper also extends the model with an algorithm for finding the upper and lower bound for apparent link-failures in an arbitrary mesh topology. The model is verified using simulations. The validity of the model is investigated using different link models. Since the radio sensing and transmission range of a node influence its ability to detect ongoing transmissions, the paper also analyze how the sensing range affects the apparent link-failure model.