optimal relay placement, some researchers have already exploited this approach. Thakur et al., in [@thakur-etal10optimal-relay-location-power-allocation], report on the problem of placing a single relay node to maximize the capacity of a broadcast relay channel in a wideband regime. Lin et al., in [@lin-etal07relay-placement-80216], numerically solve the problem of a single relay node placement, under power-law path loss and individual power constraints at the source and the relay; however, our work is primarily focused on multi-relay placement, under the exponential path-loss model and a sum power constraint among the nodes. The linear deterministic channel model ([@avestimehr-etal11wireless-network-deterministic]) is used by Appuswamy et al. in [@appuswamy-etal10relay-placement-deterministic-line] to study the problem of placing two or more relay nodes along a line so as to maximize the end-to-end data rate. Our present paper is in a similar spirit; however, we use the achievable rate formulas for the $N$-relay channel (with decode and forward relays) to study the problem of placing relays on a line having length $L$, under a sum power constraint over the nodes.

The most important difference of our paper with the literature reported above is that we address the problem of [*sequential placement*]{} of relay nodes along a line of an unknown 