“…By a slight abuse of notation, we also denote by X i = (X i,t ) t≥0 the trajectory of device X i in S. For any pair of devices X i and X j , we then consider the set of contact times Z(X i , X j ) = t ≥ 0: |X i,t − X j,t | < r and X i,t , X j,t are on the same street as the times where the devices are on the same street and r-close together, where r > 0 is another parameter in the model, the connectivity threshold. Let us note that the constraint that contact times require the devices to be on the same street can be seen as a very strict shadowing assumption [17].…”