Backhaul - The transport network connecting the Radio Access Network (RAN) to the mobile core network. In a Distributed RAN (D-RAN) architecture, it connects the cell site to the core. In a Centralized-RAN (C-RAN) architecture, it connects the physical or virtual centralized/cloud 4G/5G Baseband Units (BBUs) to the 4G/5G core.

Base Transceiver Station (BTS) - Radio-frequency signal source device. Usually a high powered device connected to the operator’s network.

Baseband Unit (BBU) - A unit of the telecom systems that processes baseband signals and can be deployed in a distributed (D-RAN) or centralized/cloud (C-RAN) manner.

Bi-Directional Amplifier (BDA) - Devices that receive, boost and amplify over-the-air signals in both directions from tower to device and from device to tower.