Description
Reference Signal Receiving Quality (RSRQ) is a fundamental Layer 1 measurement in both LTE and 5G NR networks that quantifies the quality of the received cell-specific reference signals. It is defined as the ratio N * RSRP / (E-UTRA carrier RSSI), where N is the number of resource blocks (RBs) of the E-UTRA carrier RSSI measurement bandwidth. In simpler terms, RSRQ compares the power of the desired reference signals (RSRP) to the total received power, including interference and noise, within the same measurement bandwidth. This yields a dimensionless metric, typically reported in dB, that approximates a narrowband signal-to-interference-plus-noise ratio (SINR) for the reference signals.
From an architectural perspective, RSRQ measurement is performed by the User Equipment (UE). The network configures measurement objects, reporting configurations, and measurement gaps via RRC signaling. The UE measures the RSRP on the cell-specific reference signals (CRS in LTE, SSB or CSI-RS in NR) and the Received Signal Strength Indicator (RSSI) across the configured bandwidth. The physical layer performs these measurements, and the results are filtered (using L1 and L3 filtering) before being reported to higher layers. In LTE, RSRQ is a primary measurement for Radio Resource Management (RRM), including cell selection/reselection and handover. In NR, while SS-RSRQ (based on SSB) remains important, CSI-RSRQ has been introduced for more flexible quality assessment, especially in beamformed scenarios.
The role of RSRQ in the network is multifaceted. It provides a critical input for mobility algorithms. While RSRP indicates signal strength, RSRQ indicates how 'clean' that signal is. A cell with high RSRP but poor RSRQ may be heavily congested or suffering from strong interference, making it a less desirable candidate for connection. Therefore, network algorithms often use RSRQ (or its derivatives) to trigger handovers, manage load balancing, and configure cell reselection parameters. It is a more reliable indicator of potential user throughput and connection stability than RSRP alone, especially at cell edges where interference is predominant.
Purpose & Motivation
RSRQ was introduced in LTE Release 8 to solve a fundamental limitation of using only RSRP for radio resource management. RSRP alone indicates the strength of the signal from a serving or neighboring cell but does not account for the level of interference or the overall load on the channel. A cell could have a strong RSRP but be unusable due to excessive interference from neighboring cells operating on the same frequency (co-channel interference). This could lead to poor handover decisions, where a UE connects to a strong but heavily interfered cell, resulting in degraded user experience and dropped calls.
The creation of RSRQ provided a standardized, network-controlled metric that combines signal strength and interference into a single quality indicator. This allowed for more intelligent cell selection and handover, improving overall network performance, capacity, and user-perceived quality. Its purpose expanded in subsequent releases to support new features like Carrier Aggregation (where secondary cell selection considers quality), dual connectivity, and, in NR, to operate in conjunction with beam measurements. RSRQ remains a cornerstone measurement because it addresses the classic trade-off in cellular networks between signal strength and interference, enabling algorithms that optimize for both connectivity and quality of service.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (81 CRs across 6 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-8, normative work from Rel-15.
In Release 15, the RSRQ function was updated with the introduction of the NR-SS-SINR measurement capability for LTE, providing a new metric for signal quality assessment. This was accompanied by corrections to measurement reporting procedures and UE capability signalling related to RSRQ and other measurements. Additionally, the release introduced signalling for time reference provision and made corrections to time reference information for measurement accuracy.
- Introduction of NR-SS-SINR TS 36.214CR0051
- Introduction of time reference provision TS 36.331CR3341
- Signalling for euCA (Enhancing LTE CA Utilization) TS 36.331CR3391
- Additional capability signalling for 1024QAM support TS 36.331CR4031
- RSRP result in SFTD measurement report TS 36.331CR3602
- Corrections on time reference information TS 36.331CR3654
+ 21 more changes
In Release 16, the primary change for RSRQ was the removal of RSS-based RSRQ measurements, as indicated in the CR titles. This change streamlined the measurement framework by deprecating that specific method. No other new introductions or modifications to the RSRQ function itself are detailed in the provided grounding context or list of changes for this release.
- Introduction of RSRP measurement based on RSS TS 36.214CR0055
- Introduction of signalling for high-speed train scenarios TS 36.331CR4326
- Introduction of B1C signal in BDS system in A-GNSS TS 37.355CR0248
- Introduction of B1C signal in BDS system in A-GNSS TS 38.305CR0013
- Corrections to 36.214 for Reference Point for eNB Rx – Tx time difference TS 36.214CR0057
- Removal of RSS based RSRQ measurements TS 36.331CR4748
+ 7 more changes
In Release 17, the primary enhancement related to RSRQ was the addition of a new UE capability for measuring NR-U RSSI/CO (Received Signal Strength Indicator/Channel Occupancy). Furthermore, the release introduced test applicability for L1-SINR measurement cases, which is a distinct measurement quantity from RSRQ.
- Addition of SINR measurement TS 32.425CR0200
- UE Security Capabilities signaling in NG-RAN [UE_Sec_Caps] TS 38.300CR0427
- Addition of NR-U RSSI/CO measurement UE capability TS 36.331CR4729
- Clarify the reference point for timing info in SIB16(-NB) and DLInformationTransfer in IoT NTN TS 36.331CR4937
- Correction on SIB31 signalling only in NTN cell TS 36.331CR4972
- Corrections on applicability of timing error margin of RxTEG in NR-Multi-RTT-SignalMeasurementInformation field descriptions and other Miscellaneous corrections TS 37.355CR0431
+ 6 more changes
In Release 18, the enhancements for RSRQ specifically introduced new test applicability for Reduced Capability (RedCap) devices regarding SS-RSRQ measurements. This addition ensures that the conformance testing framework properly covers the RSRQ measurement performance for these new device types. The release also included general clarifications and updates to measurement reporting and quality thresholds across various scenarios.
- MC service control signalling over 5G MBS TS 23.289CR0020
- Introduction of Measurement Quality and Time Stamp Information to E-CID [ECIDQualTimeStamp] TS 38.305CR0170
- Update to broadcast MBS sessions monitoring and the reception quality of the MBS session TS 23.289CR0057
- Resolve the EN about architecture and reference alignment in clause 4.7.1 TS 23.289CR0058
- Adding references to 3GPP TS 26.502 TS 23.289CR0089
- Update the scope clause with reference to 5G network architecture specs TS 23.289CR0091
+ 13 more changes
In Release 19, the changes related to RSRQ were not focused on modifying its core definition or measurement procedure. Instead, the release included corrections and clarifications to specification references and scopes where RSRQ is utilized, ensuring consistency across documents. Furthermore, specific test case applicability for RRM measurements, including those involving RSRQ in Non-Terrestrial Networks (NTN), was formally added.
- Introduction of B2b signal in BDS system in A-GNSS TS 37.355CR0545
- Introduction of Low-Power Wake-Up Signal and Receiver for NR TS 38.300CR1015
- Add the FRMCS requirements reference TS 23.289CR0121
- Correction of the reference in the scope clause TS 23.289CR0122
- Addition of applicability for Rel-17 RRM L1-RSRP NR-NTN test cases TS 38.522CR0730
- Correction of reference points in 23.289 Rel-19 TS 23.289CR0138
+ 2 more changes
In Release 20, the RSRQ function was enhanced to support the provisioning of connection quality information to authorized Mission Critical (MC) users, as indicated by the change to "Provide the quality of MC client connection to authorized MC users." Furthermore, clarifications were introduced regarding the reception of multicast MBS data, specifically detailing procedures for when the User Equipment is in the RRC_INACTIVE state.
Explore further
Broader topics and technologies where RSRQ plays a role.
Defining Specifications
3GPP specifications that define or reference RSRQ, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TR 21.905 vj00 | 3GPP Technical Terms and Definitions | Rel-19 |
| TS 23.289 vk10 | Mission Critical services over 5G System | Rel-20 |
| TR 23.730 ve00 | Study on extended CIoT architecture | Rel-14 |
| TS 24.312 vj00 | ANDSF Management Objects Specification | Rel-19 |
| TS 25.123 vj00 | Radio Resource Management for TDD | Rel-19 |
| TS 25.133 vj00 | UTRAN RRM Requirements for FDD | Rel-19 |
| TS 25.215 vj00 | UTRA FDD Measurement Definitions | Rel-19 |
| TS 25.225 vj00 | UTRA TDD Physical Layer Measurements | Rel-19 |
| TS 25.331 vj00 | UTRAN RRC Protocol Specification | Rel-19 |
| TS 28.627 vj00 | SON Policy NRM IRP: Requirements | Rel-19 |
| TS 28.628 vj00 | SON Policy NRM IRP Information Service | Rel-19 |
| TS 32.425 vj00 | E-UTRAN Performance Measurements | Rel-19 |
| TS 36.133 vj20 | E-UTRA RRM Requirements | Rel-19 |
| TS 36.201 vj00 | LTE Physical Layer General Description | Rel-19 |
| TS 36.214 vj00 | E-UTRA Physical Layer Measurements | Rel-19 |
| TS 36.331 vj00 | LTE RRC Protocol Specification | Rel-19 |
| TS 36.355 vj00 | LTE Positioning Protocol (LPP) | Rel-19 |
| TS 36.809 vc00 | Study on RF Pattern Matching for LTE Positioning | Rel-12 |
| TS 36.825 vd00 | Study on Additional LTE TDD Configurations | Rel-13 |
| TS 36.842 vc00 | Small Cell Enhancements for LTE Higher Layers | Rel-12 |
| TS 36.867 vd00 | LTE DL 4 Rx Antenna Port Study TR | Rel-13 |
| TS 36.878 vd00 | LTE Performance Enhancements for High Speed Scenarios | Rel-13 |
| TS 37.320 vj00 | Minimization of Drive Tests (MDT) Overview | Rel-19 |
| TS 37.355 vj20 | LTE Positioning Protocol (LPP) | Rel-19 |
| TS 37.870 vd00 | Study on Multi-RAT Joint Coordination | Rel-13 |
| TS 38.101 vj31 | NR User Equipment Radio Transmissions | Rel-19 |
| TS 38.300 vj00 | NG-RAN Overall Description | Rel-19 |
| TS 38.305 vj00 | NG-RAN UE Positioning Stage 2 | Rel-19 |
| TS 38.521 vj20 | NR Physical Layer UE Conformance Testing | Rel-19 |
| TS 38.522 vj11 | UE Conformance Test Applicability Statement | Rel-19 |
| TR 38.869 vi00 | Study on low-power wake up signal and receiver for NR | Rel-18 |
| TR 38.889 vg00 | NR-based access to unlicensed spectrum study | Rel-16 |