3GPP Glossary

Block Error Rate

The fraction of transport blocks received in error, used as a target metric for link adaptation and MCS selection.

Bandwidth Part

A contiguous subset of the cell bandwidth that a UE is configured to operate within at a given time, enabling power-saving and mixed numerologies.

Channel Quality Indicator

UE feedback indicating the highest modulation and coding scheme the current channel conditions can support.

Channel State Information Reference Signal

A configurable downlink reference signal used for channel quality measurement, beam management, and mobility measurements.

Demodulation Reference Signal

UE- or beam-specific reference signal transmitted alongside data channels to enable coherent channel estimation for demodulation.

Modulation and Coding Scheme

An index mapping to a specific modulation order and code rate combination applied to a transport block.

Master Information Block

The broadcast system information carrying the minimal set of parameters a UE needs before it can read further scheduling information.

Physical Broadcast Channel

The physical channel that carries the MIB, allowing a UE to acquire the minimum system information needed to access a cell.

Physical Downlink Control Channel

The physical channel carrying downlink control information (DCI) that schedules PDSCH/PUSCH resources and delivers other control commands.

Physical Downlink Shared Channel

The main downlink data-bearing physical channel, carrying user-plane and higher-layer control data scheduled via PDCCH.

Physical Layer

Layer 1 of the radio protocol stack, responsible for modulation, coding, and mapping of transport channels onto physical resources.

Precoding Matrix Indicator

UE feedback recommending the precoding matrix the network should apply for closed-loop MIMO transmission.

Physical Random Access Channel

The uplink physical channel used by the UE to initiate random access, enabling uplink timing synchronization and initial access.

Physical Resource Block

The basic unit of frequency-domain resource allocation, consisting of 12 consecutive subcarriers over one slot.

Physical Sidelink Broadcast Channel

The sidelink physical channel used to broadcast synchronization and system information directly between UEs in D2D/V2X communication.

Physical Uplink Control Channel

The physical channel carrying uplink control information such as HARQ feedback, scheduling requests, and CSI reports.

Physical Uplink Shared Channel

The main uplink data-bearing physical channel, used for user-plane data and, when needed, uplink control information.

Rank Indicator

UE feedback indicating the number of spatial layers (transmission rank) that can be supported for MIMO transmission.

Reference Signal Received Power

A UE measurement of the average power of reference signal resource elements, used for cell selection, reselection, and handover decisions.

Reference Signal Received Quality

A UE measurement combining RSRP and received signal strength (RSSI) to indicate signal quality relative to total channel power.

System Information Block

Broadcast messages carrying cell configuration, neighbor cell, and access-control information beyond what the MIB provides.

Signal-to-Interference-plus-Noise Ratio

A measurement expressing the ratio of desired signal power to interference and noise power, used to estimate achievable throughput.

Synchronization Signal Block

The NR block combining PSS, SSS, and PBCH, transmitted periodically to enable cell search, synchronization, and beam management.

Transport Block Size

The number of information bits contained in a transport block, derived from the MCS, allocated resource blocks, and layer count.