Description
A Fixed Reference Measurement Channel (FRC) is a fundamental conformance testing tool defined across multiple 3GPP technical specifications. It is not a functional channel used in live network operation but a test configuration. An FRC provides a complete, unambiguous definition of a physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) transmission for the purpose of radio frequency (RF) and demodulation performance testing. The definition includes all necessary parameters to generate a predictable signal: the exact transport block size (TBS), the modulation scheme (e.g., QPSK, 16QAM, 64QAM, 256QAM), the channel coding rate (based on a specific redundancy version), the physical resource block (PRB) allocation, and the reference signal configuration. During testing, the test equipment (a base station emulator) generates the signal exactly as specified by the FRC, and the device under test (UE or gNB) must successfully demodulate and decode it with an error rate below a specified threshold (e.g., Block Error Rate of 10%). The key components of an FRC are its unique identifier (e.g., FRC A1-1, FRC A3-3), the associated reference measurement channel configuration table in the specification, and the corresponding performance requirements table. Its role is to isolate and measure specific receiver capabilities, such as sensitivity, maximum input level, or adjacent channel selectivity, under a controlled and repeatable condition, ensuring all vendors test their equipment against the same benchmark.
Purpose & Motivation
The FRC exists to solve the problem of inconsistent and non-comparable radio performance testing for 3GPP-based devices. Without a fixed reference, different test labs or manufacturers could use slightly different signal configurations, leading to results that cannot be fairly compared and potentially allowing sub-standard devices to pass by exploiting test loopholes. The creation of FRCs was motivated by the need for rigorous type approval testing to guarantee a baseline level of network performance and spectral efficiency. Historically, as cellular technologies evolved from GSM to UMTS and LTE, the testing complexity grew exponentially. FRCs provide a standardized 'test vector' that ensures every UE or base station is evaluated under identical, challenging radio conditions. This guarantees that devices meeting the 3GPP performance specifications will interoperate reliably in real networks, maintaining overall network quality and user experience.
Classification
Release Timeline
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (39 CRs across 4 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the FRC (Fixed Reference Channel) function was introduced for Base Station (BS) Inter-Carrier (IC) receiver testing in TS 36.141. The release also included numerous updates and corrections to FRC definitions and indices within TS 38.104 for NR, specifically for PUSCH mapping types, DMRS configurations, and receiver requirement references. These changes ensured the FRCs properly supported new NR features like CP-OFDM and DFT-s-OFDM waveforms for both FR1 and FR2.
- 36.104 CR for BS IC receiver - FRC definitions TS 36.104CR4694
- Introduction of FRC for BS IC in 36.141 TS 36.141CR1062
- Correction on FRC indices for enhanced performance requirement type B TS 36.104CR4781
- Correction on FRC indices for enhanced performance requirement type B TS 36.141CR1146
- CR to TS 38.104 Combined updates from RAN4 #90bis and RAN4#91 From RAN4 #90bis: - R4-1903105, "Draft CR to TS 38.104: Corrections on terminologies and editorial errors" - R4-1903319, "Draft CR to TS 38.104: removal of unused definition: "minimum EIRP level under extreme condition"" - R4-1903320, "Draft CR to TS 38.104: OSDD information correction" - R4-1903457, "Draft CR to TS 38.104: Removal of FFS for FR2 TDD OFF power level requirement in clause 9.5" - R4-1903499, "Draft CR to 38.104: Correction to unwanted emissions mask for bands n7 and n38" - R4-1903836, "Draft CR to TS 38.104: Correction on description on multi-band operation in section 4.8" - R4-1904024, "Draft CR to TS 38.104 Applicability rules for BS demodulation" - R4-1904234, "draftCR: Correlation matrix for 8Rx in TS 38.104" - R4-1904723, "Draft CR to TS 38.104: Update of performance requirements for DFT-s-OFDM based PUSCH" - R4-1904726, "draftCR for 38.104 on PUSCH requirements with CP-OFDM and FR1" - R4-1904729, "Draft CR on PRACH performance requirements in TS38.104" - R4-1904734, "Draft CR on TS 38.104 Performance requirement for PUCCH format 1" - R4-1904735, "Draft CR on NR PUCCH format2 performance requirements for TS 38.104" - R4-1904739, "Draft CR to TS 38.104 BS demodulation PUCCH format 0 requirements" - R4-1904745, "draftCR: Updates to PUCCH formats 3 and 4 performance requirements in TS 38.104" - R4-1904799, "Draft CR to TS 38.104: FRC update for PUSCH FR1 mapping type B and FR2 DMRS 1+1" - R4-1904816, "Draft CR : Clarification on step 5 and step 6 for delay profiles calculation (38.104)" - R4-1904842, "Draft CR to TS 38.104 BS demodulation CP-OFDM PUSCH FR2 requirements" - R4-1905126, "draft CR to 38.104 for TAE requirements" - R4-1905139, "draft CR to TS 38.104 on EVM measurement (Annex B and C)" - R4-1905140, "Draft CR: editorial correction on FR1 spurious emission requirement in TS38.104" - R4-1905143, "Draft CR for TS 38.104: Addition of NOTE for transmitter intermodulation requirements in certain regions" - R4-1905144, "Draft CR to TS 38.104: FRC reference corrections for the Rx requirements" - R4-1905145, "Draft CR to TS 38.104: Clarification on application of interfering signal offsets for ACS, blocking and intermodulation requirements" - R4-1905148, "Draft CR to TS 38.104: Corrections on out-of-band blocking requirement" From RAN4 #91: - R4-1906002, "Draft CR to 38.104: Subclause 6.7 and 9.8 transmitter intermodulation – correction of interfering signal type" - R4-1906096, "Draft CR to 38.104: Correction of frequency range for OTA spurious emissions" - R4-1906311, "Draft CR to 38.104: Correction on FRC (Annex A)" - R4-1906346, "Removal of n65 in Rel-15 38.104" - R4-1906915, "Draft CR to TS 38.104: Clarification on application of interfering signal offsets for OTA ACS, blocking and intermodulation requirements" - R4-1906918, "Draft CR to TS 38.104: Clarification on type of interfering signal for ACS, in-band blocking and ICS requirements" - R4-1907110, "Draft CR to TS 38.104: correction of the fundamental frequency limit of 2.55GHz for the spurious emissions" - R4-1907246, "Draft CR to TS 38.104: Update of performance requirements for DFT-s-OFDM based PUSCH" - R4-1907249, "Draft CR to TS 38.104: Correction on the terminology in PUSCH FRC tables" - R4-1907252, "Draft CR to TS38.104: Updates of PRACH performance requirements" - R4-1907255, "Draft CR on NR PUCCH format2 performance requirements for TS 38.104" - R4-1907258, "Draft CR on NR UCI on PUSCH performance requirements for TS 38.104" - R4-1907261, "draftCR: Updates to PUCCH formats 3 and 4 performance requirements in TS 38.104" - R4-1907266, "Draft CR on TS 38.104 Performance requirement for PUCCH format 1" - R4-1907267, "Draft CR on TS 38.104 Performance requirement for multi-slot PUCCH format 1" - R4-1907272, "Draft CR to TS 38.104 BS demodulation PUCCH format 0 requirements" - R4-1907275, "Draft CR to TS 38.104 BS demodulation CP-OFDM PUSCH FR2 requirements" - R4-1907277, "draftCR for 38.104 on PUSCH requirements with CP-OFDM and FR1" - R4-1907629, "Draft CR to 38.104: Term “reference signal” replacing by term “ideal signal” in EVM context" - R4-1907634, "Draft CR to 38.104: corrections to the EVM annex" - R4-1907659, "Draft CR to TS 38.104 on Spurious emission Category B in FR2" - R4-1907661, "Draft CR to 38.104 Definition of contiguous transmission bandwidth" - R4-1907662, "Draft CR to 38.104: BS TAE requirements" - R4-1907664, "Draft CR to 38.104: Clarification of interferer RB frequency for narrowband blocking" - R4-1907672, "Draft CR for TS 38.104: Correction on EVM" - R4-1907689, "Correction to CA carrier spacing" TS 38.104CR0029
In Release 16, the FRC function was updated with new reference measurement channel tables for FR2, specifically for PUSCH 2T2R MCS12. The release also included corrections and clarifications to existing FRC tables for FR1 and eLAA, alongside editorial corrections to the terminology and description within the FRC annexes. Furthermore, performance requirements for various channels, including PUSCH with CP-OFDM in FR2, were updated, which inherently rely on these refined FRC definitions.
- CR for 38.104: HST PUSCH demodulation Annex including both FRC and channel model TS 38.104CR0158
- CR for 38.104: HST PUSCH demodulation FRC and channel model annexes TS 38.104CR0166
- CR for 38.104: HST PUSCH demodulation FRC and channel model annexes TS 38.104CR0219
- CR for 38.104: new FRC tables for FR2 PUSCH 2T2R MCS12 TS 38.104CR0136
- Adding FRC table description in Annex in TS38.104 v16.5.0 TS 38.104CR0257
- Correction of eLAA FRC table TS 36.141CR1282
+ 3 more changes
In Release 18, the FRC (Fixed Reference Channel) definitions were significantly updated and aligned across multiple specifications to support new capabilities and ensure consistency. Key additions and corrections included new FRC tables for NTN (Non-Terrestrial Networks), ATG (Air-to-Ground) PUSCH demodulation, and the FR2-2 frequency range, as well as specific updates for NB-IoT and performance criteria. These changes also involved aligning FRC numbers and correcting entries for various modulations, including 256QAM, across technical specifications such as TS 38.104, TS 38.108, and TS 38.181.
- (NB_IOT, NR_FR1_lessthan_5MHz_BW) CR to TS 37.113 on update of FRC used in performance criteria TS 37.113CR0139
- CR to 38.104: FRC number alignments among specifications TS 38.104CR0616
- [NR_ATG-Perf] CR on ATG PUSCH demodulation performance requirements and FRC definition (TS38.104, Rel-18) TS 38.104CR0625
- CR to 38.104: Correction of FRC numbers for 256QAM, R=682.5/1024 TS 38.104CR0615
- CR for 38.108 on RF FR2-NTN FRC alignments TS 38.108CR0087
- (NB_IOTenh3-Core)CR to TS38.113: FRC correction for performance criteria for continuous phenomena for BS TS 38.113CR0083
+ 12 more changes
In Release 19, the FRC function was updated with corrections and clarifications across multiple technical specifications. These included corrections to maximum throughput descriptions, adjustments to FRC parameters for performance requirements in FR1 interlaced PUSCH, High-Speed Train (HST) scenarios, and FR2-2 with transform precoding, as well as updates to specific FRC names and values for QPSK with a code rate of 308/1024. Additionally, a missing note on channel estimation lengths for NB-IoT NPUSCH format 1 FRC was added.
- CR to TS 36.108: Adding a missing Note on channel estimation lengths for NB-IoT NPUSCH format 1 FRC TS 36.108CR0051
- (TEI16-BDaT_FRC_thp) CR to TS 37.113: Correction of the description of maximum throughput for an FRC TS 37.113CR0147
- (NR_unlic-Perf) CR to 38.104: Correction to FRC parameters for FR1 interlaced PUSCH performance requirements TS 38.104CR0705
- (NR_HST_FR1_enh-Perf) CR to 38.104: Correction to FRC parameters for HST FR1 PUSCH performance requirements TS 38.104CR0708
- (NR_ext_to_71GHz-Perf) CR to 38.104: Correction to FRC parameters for FR2-2 PUSCH performance requirements with transform precoding enabled TS 38.104CR0711
- CR to 38.108 to update FRC name for performance requirements (QPSK, R=308/1024) TS 38.108CR0148
+ 1 more changes
Explore further
Broader topics and technologies where FRC plays a role.
Defining Specifications
3GPP specifications that define or reference FRC, 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 |
| TR 25.967 vj00 | Home NodeB RF Requirements Technical Report | Rel-19 |
| TS 36.101 vj30 | LTE UE Radio Transmission & Reception Requirements | Rel-19 |
| TS 36.104 vj10 | Base Station (BS) radio transmission and reception | Rel-19 |
| TS 36.108 vj10 | Satellite Access Node RF Requirements | Rel-19 |
| TS 36.113 vj00 | EMC Requirements for E-UTRA Base Stations | 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 36.124 vj00 | EMC for E-UTRA User Equipment | Rel-19 |
| TS 36.141 vj00 | E-UTRA BS Conformance Testing | Rel-19 |
| TS 36.181 vj30 | E-UTRA RF Test Methods for Satellite Access Node | Rel-19 |
| TS 36.747 ve00 | Enhanced CRS and SU-MIMO IM Performance Requirements | Rel-14 |
| TS 36.790 vf00 | LAA/eLAA for CBRS 3.5GHz Band in US | Rel-15 |
| TS 37.104 vj10 | MSR Base Station RF Characteristics | Rel-19 |
| TS 37.105 vj10 | AAS Base Station Transmission & Reception Requirements | Rel-19 |
| TS 37.113 vj00 | EMC Requirements for Multi-Standard Radio Base Stations | Rel-19 |
| 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 37.802 va10 | MSR BS RF Requirements for Non-Contiguous Spectrum | Rel-10 |
| TS 37.809 vb00 | E-UTRA & MSR BS Class Requirements | Rel-11 |
| TS 37.812 vb30 | Multi-band Multi-standard Radio BS Requirements | Rel-11 |
| TR 37.843 vf70 | AAS BS Radiated RF Requirement Background | Rel-15 |
| TR 37.900 vj00 | Multi-Standard Radio (MSR) Base Station Requirements | Rel-19 |
| TR 37.976 vj00 | MIMO OTA Test Methodology Study | Rel-19 |
| TR 37.977 vj00 | MIMO OTA Test Methodology | 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 38.113 vj00 | NR Base Station EMC Specification | Rel-19 |
| TS 38.174 vj10 | NR Integrated Access and Backhaul Radio Spec | Rel-19 |
| TS 38.175 vj00 | EMC for NR IAB Nodes | 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 38.551 vi30 | User Equipment (UE) Multiple Input Multiple Output (MIMO) Over-the-Air (OTA) performance | Rel-18 |
| TS 38.741 vj00 | NTN L-/S-band for NR Technical Specification | Rel-19 |
| TS 38.817 | 3GPP TR 38.817 | Rel-8 |
| TS 38.826 vg00 | NR Vehicle UE 2Rx Exception Study | Rel-16 |
| TS 38.863 vj10 | NR NTN RF and Co-existence Spec | Rel-19 |
| TR 38.921 vj00 | IMT Parameters Study for 6.4-7.1 & 10-10.5 GHz | Rel-19 |
| TR 38.922 vj20 | Study on IMT Parameters for NR in Higher Bands | Rel-19 |
