Optimizing Millimeter-Wave Backhaul Networks in Roadside Environments

With the advent of 5G, mmWave communications are being investigated for wireless backhaul. The high data rates possible with mmWave are well suited for backhaul networks, while the large number of small cells necessary to support 5G make connecting fiber to every base station difficult and costly. We investigate backhaul topologies deployed along roadsides to provide 5G service to vehicles. The challenge is to achieve the very high data rates necessary to handle backhaul traffic while managing self interference that can occur due to the near- straight-line topology that arises from a roadside deployment. We investigate wireless backhaul networks that use relay nodes and a regular triangular-wave topology to meet the performance objective. The triangular-wave is a regular topology that can be deployed on regularly-spaced lampposts alongside a road. We derive conditions necessary for the triangular-wave topology to be interference-free and throughput-optimal. We also investigate how the proposed topology performs using lamppost positions taken from a 12 km stretch of highway in Atlanta. Results show that the topology can achieve throughputs very close to the ideal case and is capable of supporting backhaul throughputs of 10+ Gbps in real roadside environments.