This topic presents the communication flow between the 5G base station (gNB) and user equipment (UE) nodes, explaining the uplink (UL) and downlink (DL) transmission.
How does a base station work?
Figure 3.5: Base station establishes one or more tunnels between each UE and the Mobile Core's User Plane. Fourth, the base station forwards both control and user plane packets between the Mobile Core and the UE. These packets are tunnelled over SCTP/IP and GTP/UDP/IP, respectively.
What is a user equipment (UE)?
User Equipment (UE) User Equipment (UE) refers to the end-user devices, such as smartphones, tablets, or IoT devices, that connect to the 5G Radio Access Network (RAN) for wireless communication. The UE communicates with the network infrastructure through the base station, which serves as the access point for wireless connections.
How does a wireless UE work?
First, each base station establishes the wireless channel for a subscriber's UE upon power-up or upon handover when the UE is active. This channel is released when the UE remains idle for a predetermined period of time. Using 3GPP terminology, this wireless channel is said to provide a bearer service.
How does a UE node transmit a BSR?
The UE node transmits a BSR with a predefined periodicity as an out-of-band packet. You can use the connectUE object function of the nrGNB object to set the periodicity of the BSR report. Scheduling grant — Upon receiving the BSR from the UE node, the base station provides grants (an out-of-band packet) to the UE node for the UL transmission.
What is a baseband unit (BBU)?
Baseband Unit (BBU) The baseband unit (BBU) plays a vital role in transmitting data from the RAN node to the core network and relaying data received from the core network to the radio unit for further transmission.
What is ul data transmission?
UL data transmission — This is an in-band packet. The UE node transmits the UL data over the physical uplink shared channel (PUSCH) when it receives the scheduling grant. This figure illustrates the DL transmission. The DL transmission consists of these packets. CSI reference signal (RS) — The gNB node sends CSI-RSs to the UE node.