BeamSniff: Enabling Seamless Communication under Mobility and Blockage in 60 GHz Networks

摘要

Recently, millimeter-wave (mmWave) is augmenting popularity in wireless communications since it provides multi-Gbps throughput by exploiting the broad unlicensed 60 GHz spectrum. Highly directional adaptive beamforming antennas are inherently employed in 60GHz to counteract the severe propagation and penetration losses experienced in this spectrum. Compared to traditional omnidirectional antennas, beamforming introduces critical challenges in medium access control, especially in link establishment and maintenance. In particular, node mobility and object blockage become crucial, which necessitates frequent beam steering to re-establish links. The state-of-the-art protocols fail to jointly address both the mobility and blockage challenges. Their approaches trigger exhaustive beam search to pair antenna sectors on every link failure which produces an excessive delay that conceivably disrupts communication and lowers the quality-of-service(QoS). In this paper, we propose BeamSniff, a novel protocol that resolves the mobility and blockage issues jointly while sustaining a seamless communication. Upon link failure, it intelligently estimates the possible cause of link failure and instantly foresees plausible paths to recover the broken link, thereby eliminating the frequent exhaustive beam search which results in reducing the overhead for link maintenance. BeamSniff is assessed extensively in our custom-built 60GHz system platform with a ray-tracing based simulator under various indoor environments. The evaluation manifests the efficiency of the protocol in sustaining seamless communication along with multi-fold throughput gain compared to state-of-the-art protocols. We observe up to 14× throughput increase in typical scenarios involving motion and blockage.