PH-distributed fault models for mobile communication

In this paper we analyze the quality of wireless data transmission. We are primarily interested in the importance of the distance between sender and receiver when measuring data loss rate and the length of lossy and loss-free periods. The ultimate purpose of this type of study is to quantify the effects of mobility. We have sampled data and find that distance certainly is an important indicator but the loss rate of packets is also determined by other factors and does not always monotonically increase with the distance. We further find that while the distribution of the length of lossy periods mostly shows an exponential decay the distribution of the length of loss-free periods does not even always monotonically decrease. Both, the packet loss probability and the distribution of the length of loss-free periods can be well represented using probabilistic models. We fit simple Gilbert-Elliot models as well as phase-type distributions to the data using different fitting tools and provide loss models that can easily be used in simulation and testbed studies.