Deployment Design of Functional Split Base Station in Fixed and Wireless Multihop Fronthaul

A new functional split mobile base station (MBS) has been getting attention for 5G and beyond 5G(BSG) to reduce an optical bandwidth. The MBS is split into three components: a central unit (CU), a distributed unit (DU), and a radio unit (RU). The link between a DU and a RU is connected by an optical fiber and well known as fronthaul. In particular, RUs will be densely deployed in antenna site to increase the mobile data rate. There is inefficiency in the bandwidth usage in the fronthaul link because all the RUs are not always in activated state. Therefore, a mobile operator needs a cost-effective fronthaul network. Employing the wireless multihop system has been studied to construct 5G/B5G fronthaul network. Both optical and wireless links should be employed since it is challenging to replace all of the optical link to the wireless link. However, the method of the deployment of the DU site to reduce the optical fiber cost has not been considered. This paper proposes a novel efficient deployment design of DU site incorporating wireless multihop connection in order to satisfactory reduce optical fiber deployment cost.