Description
Effective Isotropic Radiated Power (EIRP) is a fundamental parameter in wireless communications that quantifies the radiated power of a transmitter-antenna combination in a specific direction. It is defined as the power that would have to be supplied to a lossless isotropic antenna (a theoretical point source radiating equally in all directions) to produce the same power density as the actual antenna in its direction of maximum gain. EIRP is calculated as EIRP = Transmitter Power Output (TPO) + Antenna Gain (dBi) - Feedline Losses (dB), typically expressed in dBm or dBW. This metric is crucial for understanding the effective signal strength emitted from a base station, user equipment (UE), or any radio device.
In practice, EIRP is used extensively in link budget analysis to determine the achievable signal-to-noise ratio (SNR) and coverage range. For example, in 5G NR, base stations (gNBs) have specified EIRP limits per frequency band to ensure compliance with regulatory requirements and avoid interference with other systems. The calculation involves detailed components: the power amplifier output, combiner losses, jumper cable losses, and the antenna's gain pattern. Antenna gain, measured in dBi, amplifies the signal in certain directions, forming beams in Massive MIMO systems, which directly impacts EIRP. Specifications like 38.101 and 38.104 provide tables of maximum EIRP values for different device classes and deployment scenarios.
EIRP plays a vital role in network planning and optimization. Engineers use it to model propagation paths, ensuring sufficient coverage while adhering to emission limits set by bodies like the FCC or ETSI. In beamforming technologies, EIRP varies per beam direction, requiring dynamic calculations to manage power efficiently. It also relates to Equivalent Isotropically Radiated Power (EIRP), sometimes used interchangeably, though EIRP strictly refers to effective power considering antenna efficiency. Measurements involve specialized equipment like spectrum analyzers and calibrated antennas, as outlined in test specifications such as 38.141. By controlling EIRP, operators balance performance, interference, and regulatory compliance across diverse environments from dense urban cells to rural macro sites.
Purpose & Motivation
EIRP was developed to provide a standardized measure for comparing the radiating capabilities of different antenna systems, accounting for both transmitter power and antenna directivity. Before its adoption, specifications often relied solely on transmitter output power, which failed to capture the actual signal strength in the intended direction due to antenna characteristics. This led to inconsistencies in coverage predictions and regulatory enforcement, especially with the advent of directional antennas in cellular networks. EIRP solves this by offering a comprehensive metric that reflects real-world performance, enabling accurate link budgets and interference management.
Historically, as mobile networks evolved from omni-directional antennas in 2G to sophisticated beamforming in 5G, the need for a precise power metric grew. EIRP addresses limitations in previous approaches by incorporating antenna gain, which is critical for high-frequency bands like mmWave where beamforming is essential for coverage. It supports regulatory compliance by setting maximum power limits to prevent harmful interference and ensure spectrum sharing, such as in unlicensed bands. Its creation was motivated by the telecommunications industry's requirement for a universal parameter to facilitate equipment certification, network deployment, and international roaming, ensuring interoperability across diverse hardware and geographies.
Classification
Release Timeline
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (16 CRs across 3 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, key clarifications and corrections were introduced for the EIRP function, primarily focusing on terminology and measurement procedures. Specifically, the term "EIRP accuracy directions set" was corrected to "OTA peak directions set" in multiple test specifications. Furthermore, missing EIRP and EIS definitions were formally added to the NR base station terminology, and test procedures for EIRP and EIS were detailed for the 2D Compact Range measurement method.
- CR to TS 37.105: correction of the "EIRP accuracy directions set" into "OTA peak directions set" TS 37.105CR0109
- CR to TS 37.145-2: correction of the "EIRP accuracy directions set" into "OTA peak directions set" TS 37.145CR0047
- CR to TS 37.145-2: Correction on usage of terms TRP and EIRP TS 37.145CR0124
- CR to TP 37.843: Correction on usage of term EIRP TS 37.843CR0023
- CR to TR 37.843: Addition of 2D Compact Range. MU, calibration and test procedure for EIRP and EIS. TS 37.843CR0029
- CR to TS 38.104 on Combined updates from RAN4 #90 This document combines the proposed changes in the following Draft CRs from RAN4 #90: - R4-1900284, "Draft CR on NR PUCCH format2 performance requirements for TS 38.104" - R4-1900763, "Draft CR to TS 38.104: Update of performance requirement numbers for DFT-s-OFDM based PUSCH" - R4-1900876, "Draft CR to TS 38.104: On RX spurious emissions requirement" - R4-1900968, "Draft CR for 38.104: Performance requirements for NR PUCCH format 1" - R4-1901329, "Draft CR to 38.104: Annex C.6 correction" - R4-1901330, "Draft CR to 38.104: Abbreviations addition" - R4-1901387, "Draft CR to TS 38.104 BS demodulation PUCCH format 0 requirements" - R4-1901474, "Draft CR to TS 38.104: Corrections on transmitter co-existence and co-location requirements" - R4-1901483, "Draft CR to TS 38.104: Corrections on general intermodulation requirement" - R4-1902239, "Draft CR to TS 38.104: Addition of missing EIRP/EIS definitions in terminology in clause 3.1" - R4-1902241, "Draft CR to 38.104; clarification of BS power limits" - R4-1902245, "Draft CR to 38.104: Correction to FR2 OTA Interfering signal mean power units" - R4-1902246, "Draft CR to 38.104; Correction to definition of OTA reference sensitivity" - R4-1902260, "draft CR to TS 38.104 - update emissions scaling" - R4-1902338, "Draft CR: Update on FR1 range extension for TS38.104" - R4-1902389, "draftCR for 38.104 on PUSCH requirements with CP-OFDM and FR1" - R4-1902394, "Draft CR to TS 38.104 – PUSCH requirements with CP-OFDM for FR2" - R4-1902396, "CR: Updates to PUCCH formats 3 and 4 performance requirements in TS 38.104" - R4-1902444, "Draft CR to TS 38.104: Editorial CR for BS demodulation requirements" - R4-1902561, "Draft CR for updating PRACH performance requirements in TS38.104" - R4-1902571, "Corrections to 38.104 Delay profile calculation" - R4-1902642, "Draft CR to TS 38.104: Correction on multi-band operation related requirements" TS 38.104CR0019
+ 1 more changes
In Release 17, the EIRP function saw clarifications and corrections to test requirements and conformance limits for specific frequency bands. This included specifying EIRP limits for bands n100 and n101 based on ECC regulations and correcting the applicable frequency range for n259 band testing. Furthermore, the applicability of EIRP RF conformance test cases for FR2 standalone Enhanced Beam Correspondence was corrected.
- Correction of FR2 standalone Enhanced Beam correspondence - EIRP RF conformance test case applicability TS 38.522CR0136
- CR to TR 38.852 - clarification on the limits specified from ECC EIRP limits for band n101 TS 38.852CR0002
- CR to TR 38.853 - clarification on the limits specified from ECC EIRP limits for band n100 TS 38.853CR0002
- CR to TR 37.941: correction of n259-related frequency range for MU of the EIRP test requirement, Rel-17 TS 37.941CR0035
In Release 19, the key updates for the EIRP function centered on introducing and refining requirements for the Expected EIRP, particularly for the new frequency band n104. The enhancements included defining an expected EIRP mask core requirement for NCR (Network Controlled Repeaters) in the base specification and making corresponding improvements to the conformance testing specifications for this band.
- CR to TS 38.106 for introduction of expected EIRP mask core requirement for NCR TS 38.106CR0112
- CR to TS 38.104: improvements related to Expected EIRP for band n104 TS 38.104CR0753
- CR to TS 38.106 with improvements for EIRP mask for NCR TS 38.106CR0120
- CR to TS 38.141-2: improvements related to Expected EIRP for band n104 TS 38.141CR0649
- CR to TS 38.141-2: improvements related to Expected EIRP for band n104 TS 38.141CR0678
Explore further
Broader topics and technologies where EIRP plays a role.
Defining Specifications
3GPP specifications that define or reference EIRP, 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 25.101 vj00 | UTRA FDD UE RF Requirements | Rel-19 |
| TS 25.102 vj00 | UTRA TDD RF Characteristics | Rel-19 |
| TS 25.103 v1100 | RF Requirements for RRM | R99 |
| TS 25.104 vj00 | UTRA FDD Base Station RF Characteristics | Rel-19 |
| TS 25.105 vj00 | UTRA TDD Base Station RF Requirements | Rel-19 |
| TS 25.106 vj00 | UTRA FDD Repeater RF Performance Requirements | 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 25.141 vj00 | UTRA FDD Base Station RF Conformance Testing | Rel-19 |
| TS 25.143 vj00 | UTRA FDD Repeater RF Test Requirements | Rel-19 |
| TS 28.302 vj00 | LSA Controller IRP Management Operations | Rel-19 |
| TS 32.855 ve00 | Study on OAM Support for Licensed Shared Access | Rel-14 |
| TS 34.114 vc20 | Radiated Performance Test Procedure for UE/MS | Rel-12 |
| 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 36.106 vj00 | E-UTRA FDD Repeater RF Requirements | Rel-19 |
| TS 36.108 vj10 | Satellite Access Node RF Requirements | Rel-19 |
| TS 36.141 vj00 | E-UTRA BS Conformance Testing | Rel-19 |
| TS 36.143 vj00 | E-UTRA FDD Repeater RF Testing | Rel-19 |
| TS 36.181 vj30 | E-UTRA RF Test Methods for Satellite Access Node | Rel-19 |
| TS 36.755 vf00 | US 600 MHz LTE Band 71 Technical Report | Rel-15 |
| TR 36.763 vh00 | NB-IoT/eMTC Support for Non-Terrestrial Networks | Rel-17 |
| TS 36.790 vf00 | LAA/eLAA for CBRS 3.5GHz Band in US | Rel-15 |
| TR 36.791 vg00 | E-UTRA 2.4 GHz TDD Band for US | Rel-16 |
| TS 36.858 ve00 | LTE 2.6 GHz SDL Band Technical Report | Rel-14 |
| TS 37.104 vj10 | MSR Base Station RF Characteristics | Rel-19 |
| TS 37.105 vj10 | AAS Base Station Transmission & Reception Requirements | Rel-19 |
| TS 37.141 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 37.544 vg70 | UE Radiated Performance Test Procedures | Rel-16 |
| TS 37.812 vb30 | Multi-band Multi-standard Radio BS Requirements | Rel-11 |
| TS 37.814 vc00 | L-band Supplemental Downlink for UTRA/E-UTRA | Rel-12 |
| TS 37.840 vc10 | RF & EMC Requirements for Active Antenna Systems | Rel-12 |
| TS 37.842 vd30 | BS RF Requirements for Active Antenna Systems | Rel-13 |
| TR 37.843 vf70 | AAS BS Radiated RF Requirement Background | Rel-15 |
| TR 37.941 vj20 | RF Conformance Testing Background for Radiated BS Requirements | 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 38.106 vj20 | NR Repeater Radio Transmission and Reception | 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 38.115 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 38.161 vj10 | NR UE TRP and TRS Requirements for FR1 | 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 38.521 vj20 | NR Physical Layer UE Conformance Testing | Rel-19 |
| TS 38.522 vj11 | UE Conformance Test Applicability Statement | Rel-19 |
| TS 38.561 vj00 | UE Conformance for TRP/TRS FR1 | Rel-19 |
| TS 38.741 vj00 | NTN L-/S-band for NR Technical Specification | Rel-19 |
| TS 38.755 vj10 | NR FR1 DL Fragmented Carriers Study | Rel-19 |
| TS 38.771 vj00 | FR2-1 OTA Testing for STxMP UEs | 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 38.807 vg10 | NR beyond 52.6 GHz Study | Rel-16 |
| TR 38.808 vh00 | Study on NR above 52.6 GHz to 71 GHz | Rel-17 |
| TR 38.810 vg70 | NR OTA Test Methods Study | Rel-16 |
| TS 38.811 vf40 | Study on NR Support for Non-Terrestrial Networks | Rel-15 |
| TR 38.815 vf10 | NR Frequency Range 24.25-29.5 GHz Study | Rel-15 |
| TS 38.817 | 3GPP TR 38.817 | R99 |
| TS 38.821 vg20 | NR Support for Non-Terrestrial Networks | Rel-16 |
| TS 38.831 vg10 | UE RF Requirements for FR2 Enhancements | Rel-16 |
| TR 38.834 vh20 | NR FR1 TRP/TRS Test Methodology | Rel-17 |
| TR 38.839 vh00 | Simultaneous Rx/Tx band combinations | Rel-17 |
| TR 38.847 vh20 | NR 47.2-48.2 GHz Frequency Range | Rel-17 |
| TR 38.849 vi50 | Technical Report | 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 38.858 vi20 | Technical Report on Evolution of NR Duplex Operation | Rel-18 |
| TS 38.863 vj10 | NR NTN RF and Co-existence Spec | Rel-19 |
| TR 38.864 vi10 | Technical Report on Network Energy Savings for NR | Rel-18 |
| TR 38.868 vh00 | Optimizations of pi/2 BPSK uplink power in NR | Rel-17 |
| TS 38.870 vj20 | Enhanced OTA Test Methods for NR FR1 TRP/TRS | Rel-19 |
| TR 38.871 vi20 | Technical Report | Rel-18 |
| TR 38.876 vi20 | Technical Report on Air-to-Ground Network for NR | Rel-18 |
| TR 38.877 vi10 | Technical Report | Rel-18 |
| TR 38.881 vi00 | Technical Report on Lower MSD for Inter-band CA/EN-DC/DC | Rel-18 |
| TR 38.884 vi20 | Technical Report | Rel-18 |
| TR 38.886 vg30 | NR V2X UE Radio Transmission & Reception | Rel-16 |
| TS 38.887 vg00 | NR Band n259 Specification (39.5-43.5 GHz) | Rel-16 |
| TR 38.892 vi00 | Technical Report | Rel-18 |
| TR 38.894 vi00 | Technical Report | Rel-18 |
| TR 38.903 vj00 | Test Tolerances & Measurement Uncertainties | Rel-19 |
| TR 38.908 vj10 | NR Band n104 FSS UL Protection | Rel-19 |
| TR 38.912 vj00 | Study on New Radio Access Technology | Rel-19 |
| TR 38.922 vj20 | Study on IMT Parameters for NR in Higher Bands | Rel-19 |
