# MoN15: Fifteenth Mathematics of Networks meeting

## Pete Pratt and Kostas Koufos (Bristol) – How does mobility affect the connectivity and temporal correlation of interference in ad hoc networks?

The dynamic nature of ad hoc wireless networks means that connections are continually made and broken due to user mobility. This mobility of devices, for example modelled by the random waypoint mobility (RWPM) model, can induce an inhomogeneous distribution of nodes, and can create regions of high interference causing the network to become disconnected. Motivated by Penrose’s result that the main obstacle for full connectivity in random geometric graphs (dim > 1) are isolated nodes, we consider the probability that a receiver can successfully decode a signal from its nearest transmitter under the Signal-to-Interference-plus-Noise-Ratio (SINR) connection model. It is of particular interest to identify the optimal spatial distribution in order to maximise network performance.
Besides single snapshot SINR statistics, another metric of interest in mobile networks is the variation of the interference field and hence SINR over time. The temporal correlation of interference due to mobility impacts the correlation of the receiver’s outage and subsequently many network performance metrics, e.g., local and multi-hop delay, end-to-end throughput, etc. In areas with blockage, the continued transitions in the propagation conditions due to user mobility, (from line of sight to non-line of sight and vice versa) will reduce the temporal correlation of interference. Importantly, when the user density becomes much higher than the density of blockages, the correlation of the interference levels generated by different users dominates the randomness introduced by the mobility, and the temporal correlation of interference can remain high.

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Contact:
Keith Briggs
()
or
Richard G. Clegg (richard@richardclegg.org)