REFSENS

Reference Sensitivity power level

Physical Layer →
Introduced in Rel-4 Also in: User Equipment

REFSENS is the minimum input signal power at which a user equipment can achieve a specified bit error rate, a key parameter for determining coverage and link budgets in cellular networks.

Category
Physical Layer
Introduced
Rel-4
Where
Radio Access Network › NG-RAN (5G)
Also touches
1 segments
Specifications
79 specs
REFSENS Description Purpose Related Classification Detected Changes Specifications

Description

Reference Sensitivity (REFSENS) is a fundamental performance metric for User Equipment (UE) receivers in cellular networks, defined as the minimum received power level at the antenna connector required to achieve a specified bit error rate (BER) or block error rate (BLER). It is measured under ideal conditions with additive white Gaussian noise (AWGN) and specific reference measurement channels. REFSENS evaluates the receiver's ability to detect and decode weak signals, directly impacting network coverage and link budget calculations. The parameter is specified for various operating bands, modulation schemes, and channel bandwidths across 3GPP technologies including LTE and NR.

The measurement of REFSENS involves applying a test signal at the UE antenna port and gradually reducing the power until the target error rate is reached. This process ensures that the receiver meets minimum sensitivity requirements, which are essential for reliable operation at cell edges or in low-signal environments. Key factors influencing REFSENS include receiver noise figure, implementation losses, and the efficiency of baseband processing algorithms. The parameter is defined for different physical channels, such as PSS/SSS for synchronization and PDSCH for data reception, each with its own sensitivity thresholds.

REFSENS plays a crucial role in network planning and optimization by determining the maximum allowable path loss between the base station and UE. It is used in link budget calculations to estimate cell radius and ensure consistent service quality. By standardizing REFSENS, 3GPP ensures interoperability and performance consistency across devices from different manufacturers. It also drives advancements in receiver design, encouraging improvements in low-noise amplifiers, filters, and digital signal processing to achieve better sensitivity and extend coverage.

Purpose & Motivation

REFSENS was introduced to establish a standardized benchmark for receiver sensitivity, ensuring that all UEs meet minimum performance requirements for reliable network operation. Prior to standardization, variations in receiver design could lead to inconsistent coverage and user experience, particularly in weak signal conditions. 3GPP defined REFSENS to provide a common metric for testing and certification, enabling fair performance comparisons and guaranteeing baseline quality across devices.

The primary problem REFSENS addresses is ensuring that UEs can maintain communication links at the edge of cell coverage, where signal strength is minimal. It solves issues related to dropped calls, poor data rates, and unreliable service in challenging radio environments. Historical context includes the evolution from analog to digital cellular systems, where receiver sensitivity became increasingly critical for supporting higher data rates and complex modulation schemes.

REFSENS also supports network efficiency by enabling accurate link budget calculations, which optimize base station placement and transmit power settings. It motivates continuous improvement in receiver technology, leading to better energy efficiency and longer battery life for UEs. The creation of REFSENS was driven by the need for robust performance in diverse deployment scenarios, including rural areas, indoor environments, and high-interference situations, ensuring that cellular networks deliver consistent service quality worldwide.

Classification

Part ofAWGN

Detected Changes Across Releases

from 3GPP Change Requests

Specific changes extracted from the „Change history“ tables of 3GPP specifications (97 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.

Studied in Rel-4, normative work from Rel-15.

Rel-15 14 changes

In Release 15, the REFSENS (Reference Sensitivity) function was refined with specific corrections and clarifications for Over-the-Air (OTA) testing. These included a correction to the definition of OTA reference sensitivity itself and improvements to the polarization wording for its measurement. Furthermore, the release introduced an additional reference angular step criteria for OTA reference sensitivity testing as detailed in Annex F.2.2.

  • CR of test on BS REFSENS for subPRB feature TS 37.141CR0816
  • CR to TS 37.145-2: Corrections on OTA Transmit ON/OFF power TS 37.145CR0042
  • CR to TS 37.145-2 - polarisation wording improvements for OTA reference sensitivity TS 37.145CR0068
  • Correction to definition of OTA reference sensitivity TS 37.145CR0073
  • Correction to TDD OFF power requirement TS 37.145CR0075
  • CR to TS 37.145-2: additional reference angular step criteria in Annex F.2.2 TS 37.145CR0082

+ 8 more changes

Rel-16 13 changes

In Release 16, the REFSENS (Reference Sensitivity) function for NR (New Radio) was specifically corrected, as indicated by a dedicated Change Request. This correction was part of a broader set of updates to receiver requirements in TS 38.104, which also included clarifications for Over-the-Air (OTA) testing and corrections to interference levels for dynamic range.

  • CR to TS 37.141 with addition of reference to data content for test models TS 37.141CR0884
  • CR to TS 37.141: Correction of references for NB-IoT testing TS 37.141CR0899
  • CR to TS 37.145-2 with addition of reference to data content for test models TS 37.145CR0169
  • CR Modulation fallback for total power dynamic range in 37.145-2 clause 6.4.4.4.2.4 TS 37.145CR0210
  • CR to 37.145-2: Correction on interference level of receiver dynamic range requirement TS 37.145CR0226
  • CR to TS 37.145-2: internal TR references corrections (wrt. TR 37.941 for OTA BS testing), Rel-16 TS 37.145CR0228

+ 7 more changes

Rel-17 7 changes

In Release 17, the REFSENS function saw updates related to clarifying its reference to Fixed Reference Channels (FRCs) in the core requirements specification. Furthermore, specific refinements were made for Railway communications (FRMCS), correcting deployment aspects and related output power limits for the n100 and n101 frequency bands. These changes ensured alignment with updated regulatory references, such as the EU Decision.

  • CR to TS 38.104 on reference to FRCs TS 38.104CR0411
  • CR to TS 38.108: removal of NTN SAN output power accuracy requirements for the extreme test conditions, Rel-17 TS 38.108CR0011
  • Correction to IAB-MT timing reference point in TS 38.174 TS 38.174CR0042
  • (NR_RAIL_EU_1900MHz_TDD-Core) CR to TR 38.852 on correction of reference to EU Decision TS 38.852CR0007
  • (NR_RAIL_EU_1900MHz_TDD-Core) CR to TR 38.852: Corrections on FRMCS n101 deployment aspects and related output power limits, Rel-17 TS 38.852CR0008
  • (NR_RAIL_EU_900MHz-Core) CR to TR 38.853 on correction of reference to EU Decision TS 38.853CR0007

+ 1 more changes

Rel-18 41 changes

In Release 18, the REFSENS (Reference Sensitivity) function was updated to include new operating bands, specifically adding bands 253 and 254 into the relevant test case (7.3A) for UE category M1. The release also introduced updates to complete reference sensitivity test cases with variable Tx-Rx spacing specifically for NB-IoT operating in NTN (Non-Terrestrial Network) bands.

  • CR to add B54/n54 as protected band and correct reference clause in 6.5B.4.3 TS 36.102CR0009
  • (LTE_NBIoT_eMTC_NTN_req-Core) Correction of reference to Suspended version of ITU-R SM.329 Recommendation TS 36.102CR0061
  • CR on output power dynamic range for IoT NTN TS 36.108CR0010
  • (LTE_Relay-Core) Correction of reference to Suspended version of ITU-R SM.329 Recommendation TS 36.116CR0020
  • CR to 36.181: Test model correction for total power dynamic range requirements TS 36.181CR0004
  • Update of reference measurement channels in Annex A.3.12 TS 36.521CR0006

+ 35 more changes

Rel-19 22 changes

In Release 19, the REFSENS function was updated with specific corrections and clarifications for reference sensitivity levels, particularly for NB-IoT operation in NTN (Non-Terrestrial Networks) and in-band NR scenarios. The enhancements included defining reference sensitivity requirements for Base Stations (BS) and Standalone NR (SAN) nodes, including the addition of a new SAN type 1-H for Over-The-Air (OTA) sensitivity testing. Furthermore, corrections were made to the application of these levels for 3 MHz channel bandwidths and to the associated reference measurement channel numbering.

  • (IoT_NTN_FDD_LS_band-Core) Correction of the IoT NTN band 254 NS flag references to the sub-clauses with additional requirements TS 36.102CR0080
  • Addition of power class 1 and power class 2 in test case 6.2B.1 UE maximum output power for category NB1 and NB2 TS 36.521CR0119
  • IoT NTN power density tests - MU and TT update TS 36.521CR0126
  • Duplicated reference TS 36.521CR0136
  • CR to TS 38.141-2 on clarification of LP-WUS power boosting TS 38.141CR0674
  • CR to TR 38.774 on BS rated carrier output power and rated total output power TS 38.774CR0001

+ 16 more changes

Explore further

Broader topics and technologies where REFSENS plays a role.

Defining Specifications

3GPP specifications that define or reference REFSENS, with the latest known release. Sourced from the 3GPP document catalog — see methodology.

SpecificationTitleRelease
TS 25.142 vj00 UTRA TDD Base Station RF Test Methods Rel-19
TS 36.101 vj30 LTE UE Radio Transmission & Reception Requirements Rel-19
TS 36.102 vj10 E-UTRA UE Satellite Access RF Requirements Rel-19
TS 36.108 vj10 Satellite Access Node RF Requirements Rel-19
TS 36.116 vj00 E-UTRA Relay RF Requirements Rel-19
TS 36.117 vj00 E-UTRA Relay RF Test Methods & Requirements Rel-19
TS 36.181 vj30 E-UTRA RF Test Methods for Satellite Access Node Rel-19
TS 36.521 vj00 E-UTRA UE Conformance ICS Proforma Rel-19
TS 36.714 3GPP TR 36.714 Rel-4
TS 36.715 3GPP TR 36.715 Rel-4
TS 36.716 3GPP TR 36.716 Rel-4
TS 36.744 ve00 CBRS 3.5GHz Band Specification for US Rel-14
TS 36.755 vf00 US 600 MHz LTE Band 71 Technical Report Rel-15
TS 36.761 vf00 Extended-Band 12 Study Report Rel-15
TR 36.770 vi00 Technical Report for High Power UE in LTE Band 14 Rel-18
TS 36.790 vf00 LAA/eLAA for CBRS 3.5GHz Band in US Rel-15
TS 36.833 3GPP TR 36.833 Rel-4
TS 36.852 3GPP TR 36.852 Rel-4
TS 36.858 ve00 LTE 2.6 GHz SDL Band Technical Report Rel-14
TS 36.860 3GPP TR 36.860 Rel-4
TS 36.899 3GPP TR 36.899 Rel-4
TS 37.141 vj10 RF Test Methods for Multi-Standard Radio Base Stations Rel-19
TS 37.145 vj10 AAS Base Station Conducted Conformance Testing Rel-19
TS 37.716 3GPP TR 37.716 Rel-4
TS 37.717 3GPP TR 37.717 Rel-4
TS 37.718 3GPP TR 37.718 Rel-4
TS 37.719 vj00 3GPP TR 37.719: Dual Connectivity Band Combinations Rel-19
TS 37.814 vc00 L-band Supplemental Downlink for UTRA/E-UTRA Rel-12
TS 37.825 vg00 High Power UE (PC2) for EN-DC TDD-TDD Rel-16
TS 37.862 vj00 Adding channel bandwidth in existing NR bands Rel-19
TS 37.863 3GPP TR 37.863 Rel-4
TS 37.872 vf10 Technical Report on SUL & LTE-NR DC with SUL Rel-15
TR 37.878 vi00 Technical Report on Rel-18 NR V2X Band Combinations Rel-18
TR 37.880 vh20 High-power UE for fixed-wireless/vehicle use Rel-17
TS 37.898 vj00 Rel-19 HPUE for EN-DC Band Combinations Rel-19
TS 38.101 vj31 NR User Equipment Radio Transmissions Rel-19
TS 38.104 vj20 NR Base Station RF Requirements Rel-19
TS 38.108 vj20 NTN NR Satellite Access Node RF Requirements Rel-19
TS 38.115 vj20 NR Repeater RF Conformance Testing Part 1 Rel-19
TS 38.141 vj20 NR Base Station RF Conformance Testing Part 1 Rel-19
TS 38.174 vj10 NR Integrated Access and Backhaul Radio Spec Rel-19
TS 38.176 vj20 IAB Conformance Testing Specification Rel-19
TS 38.181 vj10 NR Satellite Access Node RF Testing Rel-19
TS 38.191 vj00 NR Ambient IoT RF Characteristics Rel-19
TS 38.194 vj00 Ambient IoT Base Station RF Spec Rel-19
TS 38.521 vj20 NR Physical Layer UE Conformance Testing Rel-19
TS 38.716 3GPP TR 38.716 Rel-4
TS 38.717 3GPP TR 38.717 Rel-4
TS 38.718 3GPP TR 38.718 Rel-4
TS 38.719 vj00 Rel-19 NR SUL Configurations and CA Band Combinations Rel-19
TS 38.741 vj00 NTN L-/S-band for NR Technical Specification Rel-19
TS 38.746 vj00 High Power UE for NR Inter-band CA/DC Rel-19
TS 38.750 vj00 High Power UE for NR Inter-band CA/DC Rel-19
TS 38.755 vj10 NR FR1 DL Fragmented Carriers Study Rel-19
TS 38.774 vj00 Rel-19 LP-WUS/WUR RF Requirements TR Rel-19
TR 38.785 vh00 UE radio transmission for enhanced NR sidelink Rel-17
TR 38.786 vi20 Technical Report for NR Sidelink Evolution Rel-18
TS 38.787 vj00 UE Radio Transmission for Sidelink CA in ITS Band Rel-19
TS 38.793 vj00 Simultaneous Rx/Tx Band Combinations TR Rel-19
TS 38.796 vj00 Rel-19 High Power UE for NR FR1 Rel-19
TS 38.809 vg60 IAB Radio Transmission & Reception Background Rel-16
TS 38.817 3GPP TR 38.817 Rel-4
TS 38.826 vg00 NR Vehicle UE 2Rx Exception Study Rel-16
TR 38.839 vh00 Simultaneous Rx/Tx band combinations Rel-17
TR 38.841 vh00 High power UE for NR inter-band CA Rel-17
TR 38.842 vh00 High Power UE for NR CA with Multiple Bands Rel-17
TR 38.850 vi10 Technical Report for Rel-18 High Power UE Rel-18
TR 38.852 vh50 1900MHz NR band for European Rail Mobile Radio Rel-17
TR 38.853 vh50 900MHz NR Band for European Rail Mobile Radio Rel-17
TR 38.860 vh00 NR; Study on Extended 600 MHz NR band Rel-17
TS 38.863 vj10 NR NTN RF and Co-existence Spec Rel-19
TR 38.868 vh00 Optimizations of pi/2 BPSK uplink power in NR Rel-17
TS 38.873 vg00 NR Band n48 Technical Report Rel-16
TR 38.881 vi00 Technical Report on Lower MSD for Inter-band CA/EN-DC/DC Rel-18
TR 38.886 vg30 NR V2X UE Radio Transmission & Reception Rel-16
TR 38.892 vi00 Technical Report Rel-18
TR 38.894 vi00 Technical Report Rel-18
TR 38.896 vi00 Technical Report for High Power UE (Power Class 2) for NR FR1 FDD Rel-18
TR 38.899 vi00 Technical Report for High Power UE Rel-18