Optimal Delay–Throughput Tradeoffs in Mobile Ad Hoc Networks

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, we investigate the delay–throughput tradeoffs in mobile <emphasis emphasistype="boldital">ad-hoc</emphasis> networks. We consider four node mobility models: 1) two-dimensional independent and identically distributed (i.i.d.) mobility, 2) two-dimensional hybrid random walk, 3) one-dimensional i.i.d. mobility, and 4) one-dimensional hybrid random walk. Two mobility time scales are included in this paper. i) Fast mobility, where node mobility is at the same time scale as data transmissions. ii) Slow mobility, where node mobility is assumed to occur at a much slower time scale than data transmissions. Given a delay constraint <emphasis><formula formulatype="inline"><tex>$D$</tex> </formula></emphasis>, we first characterize the maximum throughput per source–destination (S-D) pair for each of the four mobility models with fast or slow mobiles. We then develop joint coding–scheduling algorithms to achieve the optimal delay–throughput tradeoffs. </para>