  Due to the rapid densification of small cells in 5G and beyond cellular
networks, deploying wired high-bandwidth connections to every small cell base
station is difficult, particularly in older metropolitan areas where
infrastructure for fiber deployment is lacking. For this reason, mmWave
wireless backhaul is being considered as a cost-effective and flexible
alternative that has potential to support the high-rate transmission needed to
accommodate backhaul traffic demands. However, maintaining a high network
survivability is extremely important since networks based on mmWave
communication are susceptible to short-term blockages or node failures caused
by unforeseen events. Therefore, to realize a robust mmWave backhaul network,
several works propose to adopt a triangular-wave topology in roadside
environments, which can eliminate the mutual interference among backhaul links,
and provide robustness to blockage effects. Based on this novel topology, we
investigate a blockage type detection scheme, which reacts to blockage effects
quickly and assists in various path reconfiguration approaches.
