Rank-Based Low-Latency Scheduling for Maximum Fronthaul Accommodation in Bridged Network

Fronthaul bridged networks have attracted attention to transport time-sensitive fronthaul streams in the centralized radio access network (C-RAN) architecture. When the functional split is changed and time-division duplex (TDD) is employed in the C-RAN architecture, the data rate in fronthaul becomes variable and the global synchronization of fronthaul streams will occur. In this case, it is critical to reduce the queuing delay among fronthaul streams to efficiently accommodate a number of radio equipments in a bridged network. In this paper, we propose a novel rank-based queue scheduling method for achieving low-latency in a fronthaul bridged network. The proposed scheme considers the frame-level queuing delay caused by global synchronization with the TDD. The worst-case delay of fronthaul flows is minimized, and the number of accommodated fronthaul streams is maximized. We confirmed with computer simulations that the proposed scheme can minimize the worst case delay and increase the number of accommodated fronthaul streams.