Massive video analytics systems, comprised of many densely deployed cameras and supporting edge servers, are driving innovation in many areas including smart retail stores and security monitoring. To support such systems the challenge lies in collecting video footage in a way that maximizes end-to-end application goals, and scales this performance as camera density increases to meet application needs. This paper presents Spider, a multi-hop, millimeter-wave (mmWave) wireless relay network design that meets these needs. To mitigate physical mmWave link blockage, Spider integrates a low-latency Wi-Fi control plane with a mmWave relay data plane, allowing agile re-routing around blockages. Spider proposes a novel video bit-rate allocation algorithm coupled with a scalable routing algorithm that works hand-in-hand toward the application-level objective of maximizing video analytics accuracy, rather than simply maximizing data throughput. Our experimental evaluation uses a combination of testbed deployment and trace-driven simulation and compares against both Wi-Fi and mmWave mesh schemes that operate without Spider’s algorithms. Results show that Spider is able to sup-port camera densities up to 176% higher (gains of 2.76×) than the best-performing comparison scheme, allowing it alone to meet real-world camera density targets (4–250 cameras/1,000 sq. ft., depending on application). Further experiments demonstrate Spider’s scalability in the presence of failures, with a 5.4–100× reduction in average failure recovery time.

Mobile operators are poised to leverage millimeter wave technology as 5G evolves, but despite efforts to bolster their reliability indoors and outdoors, mmWave links remain vulnerable to blockage by walls, people, and obstacles. Further, there is significant interest in bringing outdoor mmWave coverage indoors, which for similar reasons remains challenging today. This paper presents the design, hardware implementation, and experimental evaluation of mmWall, the first electronically almost-360 degree steerable metamaterial surface that operates above 24 GHz and both refracts or reflects incoming mmWave transmissions. Our metamaterial design consists of arrays of varactor-split ring resonator unit cells, miniaturized for mmWave. Custom control circuitry drives each resonator, overcoming coupling challenges that arise at scale. Leveraging beam steering algorithms, we integrate mmWall into the link layer discovery protocols of common mmWave networks. We have fabricated a 10 cm by 20 cm mmWall prototype consisting of a 28 by 76 unit cell array, and evaluate in indoor, outdoor-to-indoor, and multi-beam scenarios. Indoors, mmWall guarantees 91% of locations outage-free under 128-QAM mmWave data rates and boosts SNR by up to 15 dB. Outdoors, mmWall reduces the probability of complete link failure by a ratio of up to 40% under 0-80% path blockage and boosts SNR by up to 30 dB.