A novel MIMO DoF model for multi-hop networks

The rapid advances of MIMO to date have mainly stayed at the physical layer or single-hop communications. Such advantages have not been fully realized at the network level, particularly for multi-hop networks. This is mainly due to the lack of a tractable and accurate model that can characterize MIMO's powerful capabilities such as spatial multiplexing (SM) and interference cancellation (IC). Recently a new DoF-based model was proposed to capture MIMO's SM and IC capabilities in multi-hop networks. This model is based on a novel node-ordering concept and only requires simple numeric computation on DoFs. In this article we review previous models for MIMO and then describe this new DoF model. This new DoF model has the potential to enable significant advances in MIMO research in the networking community.