Optically Backhauled Moving Network for Local Trains: Architecture and Scheduling

The concept of moving cell in cellular systems has been discussed for 5G group mobility where rapidly moving platforms such as trains carry a large number of user terminals. It has been considered to employ wireless backhaul for moving cell, the problem of which is its limited and unstable bandwidth. To realize high bandwidth with wireless backhaul, a large number of base stations (BSs) are required along the railway. Therefore, this paper proposes the concept of optically backhauled moving network (OBMN) for local trains to efficiently provide backhaul links for local trains. In the OBMN, an autonomous BS (ABS) is set on the top of a train and is connected to a gateway via optical backhaul. While the user terminals onboard move, the ABS set on the train always satisfies the moving demands through high-bandwidth optical backhaul. The effectiveness of the proposed architecture and scheduling was confirmed by examining two case studies in the suburban and urban areas in Tokyo. The number of required BSs and deployment cost are reduced by half with the proposed OBMN compared with the existing static deployment.