The spectrum-rich millimeter wave (mmWave) frequencies have the potential to alleviate the spectrum crunch that the wireless and cellular operators are already experiencing. However, compared with traditional wireless communication in the sub-6 GHz bands, due to small wavelengths most objects such as human body, cause significant additional path losses (up to 20 dB), which can entirely break the mm Wave link. Also, mmwave links suffer from limited range of communication. In this paper, we resort to network layer solutions to demonstrate the benefits of multi-hop routing in mitigating the blockage issue and extending communication range in mm Wave band. To this end, we develop a hop-by-hop multi-path routing protocol that finds one primary and one backup next-hop per destination in order to guarantee reliable and robust communication under extreme stress conditions. System-level simulations based on the IEEE 802.11ad specifications demonstrate that the proposed routing protocol provides a reliable end-to-end throughput performance, while satisfying the latency requirements.
