With the recent interest in large scale sensor networks, renewed attention at the physical layer has been afforded to communication networks wherein messages are transmitted via a chain of relays from source to destination. Due to propagation effects which cause distance dependent attenuation, a multihop approach has the potential to significantly reduce the overall transmission power needed to achieve a certain level of fidelity by decomposing a long distance link into multiple shorter links with improved channels. However, multihopping comes at a price. There is potential for increased delay, error propagation, and interference. Herein, multihopping networks are investigated from multiple perspectives and the challenges unique to such networks are underscored. Exemplar problems include: distributed space-time coding for multihop networks and the associated achievable performance which requires analysis of so-called product channels; a new packet scheduling problem over multihop link to achieve minimal energy consumption; and a novel error exponent analysis of communication over multihop networks which enables the consideration of delay versus performance for such networks. Preliminary results and future directions will be highlighted.
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