Error propagation and the achievable throughput-delay trade-off in wireless networks

New results on the achievable trade-off between the per-node throughput T(n) and the average delay D(n) in a static wireless network of n nodes are presented for physical link models. For links modeled by channels with additive white Gaussian noise with power-law attenuation, a trade-off of only D(n) = ⊖ (n (log n) T(n)) is guaranteed for T(n) = ⊖(n^-½). This follows from showing that there is significant information loss in the network due to error propagation, unless the length of the channel code employed is sufficiently high. Constraining the block length to be bounded yields worse trade-offs: only ⊖(n (log n)² T(n)) is guaranteed for optimal throughput, provided there is rich fading diversity.