Delay limited capacity of ad hoc networks: asymptotically optimal transmission and relaying strategy

The delay limited capacity of an ad hoc wireless network confined to a finite region is investigated. A transmission and relaying strategy making use of the nodes´ motion to maximize the throughput is constructed. An approximate expression for the capacity as a function of the maximum allowable delay is obtained. It is found that there exists a critical value of the delay such that: (1) for values of the delay d below critical, the capacity does not benefit appreciably from the motion, (2) for moderate values of the delay d above critical, the capacity that can be achieved by taking advantage of the motion increases as d^2/3, (3) the dependence of the critical delay on the number of nodes is a very slowly increasing function (n^1/14). Finally, asymptotic optimality of the proposed strategy in a certain class is shown.