Assignment Strategies for Mobile Data Users in Hierarchical Overlay Networks: Performance of Optical and Adaptive Strategies

In this paper, we present a framework and several analytical results pertaining to the performance of two assignment strategies based on the user's velocity and the amount of data to be transmitted. The main contribution is to prove that the minimum average number of users in the system, as well as the minimum expected system load for an incoming user, are the same under both assignment strategies. We provide explicit analytical expressions as well as unique characterizations of the optimal thresholds on the velocity and amount of data to be transmitted. These results are very general and hold for any distribution of user profiles and any call arrival rates.