  Recently, it has been shown that a quantize-map-and-forward scheme
approximately achieves (within a constant number of bits) the Gaussian relay
network capacity for arbitrary topologies. This was established using Gaussian
codebooks for transmission and random mappings at the relays. In this paper, we
show that the same approximation result can be established by using lattices
for transmission and quantization along with structured mappings at the relays.
