The term Node B(NB) or NodeB is used in UMTS for the radio base station. In theSystem Architecture Evolution( SAE) of Long Term Evolution( LTE) it is the EvolvedNode B(eNodeB or eNB) and in 5G it is the Next Generation NodeB( gNB). In all mobile networks, it is the station connected to the mobile network that communicates directly with the mobiledevice.
The UMTS base station Node B has only limited functionality and is controlled by the radio network controller( RNC). It supplies several UMTS radio cells. It usually consists of three antennas, each of which transmits with a transmission power of 20 W. By adapting the transmitting power to the receiving field strength of the mobile device, the maximum transmitting power of 20 W is normally not exceeded. The situation is different if the NodeB supports High Speed Downlink Packet Access( HSDPA).
Together with the Radio Network Controller (RNC), NodeB forms the UMTS access network UTRAN. The NodeB and the antenna can be in close proximity to each other, but they can also be connected via Remote Radio Heads( RRH), in which case the connection is lossless via a digital link and can have a greater distance.