Considering a three dimensional TH-UWB wireless sensor network with n static identical randomly located sensor nodes in a sphere of volume normalized by one cubic meter, the formula for upper and lower bounds on the energy dissipation of some sensor node transmitting a data packet containing R bits to the sink node by multihop fashion are derived using Vapnik-Chervonenkis theory and Voroni tessellation covering sensor field.The main finding is that the upper and lower bounds on the energy dissipation are in inverse proportion to the node density n in the network.Thus,large-scale dense TH-UWB wireless sensor network is more preferable.