Relay characteristic impact on energy consumption for heterogeneous networks in a LOS channel

Indoor heterogeneous wireless sensor networks are considered in this letter. We analyze the power consumption for multihop communications with non-regenerative relays that can only amplify the received signal without decoding and coding it. Since sensor nodes are usually battery operated so that energy consumption is a crucial issue, we determine the minimal consumption in the different configurations for a given quality of service. The important aspects of the work is that we propose a narrowband Ricean propagation environment that varies with source-destination distance and take into account hardware aspects, and especially the relays´ efficiency. We show not only that this characteristic has an important impact on the gain that multihop can bring, but also that in a few cases with a high impact on the consumption, the direct link is preferable to the two or three hops scenarios.