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
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (123 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the EIRP function was refined through corrections to its definition and usage across several specifications, including TS 37.145-2 and TR 37.843. Specifically, the term "EIRP accuracy directions set" was corrected to "OTA peak directions set," and detailed test procedures, such as the addition of the 2D Compact Range method for EIRP and EIS measurements, were introduced. Furthermore, missing EIRP definitions were added to the terminology in TS 38.104 to clarify its application for New Radio (NR) base stations.
- New Annex to TR 37.843: Power density measurements close to EUT TS 37.843CR0006
- CR to TS 38.113 Cat.B draftCRs R4-1802055 - Draft CR to Section 6.3 in TS 38.113 (NR) Performance criteria for continuous phenomena for Ancillary equipment R4-1802056 - Draft CR to Section 6.4 in TS 38.113 (NR) Performance criteria for transient phenomena for Ancillary equipment R4-1802057 - Draft CR to Section 8.4 in TS 38.113 (NR) Test method for conducted emissions AC mains power input output port R4-1803318 [NR] DraftCR 38113 Test conditions (4) TS 38.113CR0003
- CR to TS 37.105: correction of the "EIRP accuracy directions set" into "OTA peak directions set" TS 37.105CR0109
- Correction to TDD OFF power requirement TS 37.105CR0124
- CR to TS 37.145-2: Corrections on OTA Transmit ON/OFF power TS 37.145CR0042
- CR to TS 37.145-2: correction of the "EIRP accuracy directions set" into "OTA peak directions set" TS 37.145CR0047
+ 21 more changes
In Release 16, the EIRP-related specifications were updated with new radiated emission test methods and requirements, specifically for Integrated Access and Backhaul (IAB) nodes and ancillary equipment. The release introduced clarifications on rated carrier output power symbols and added radiated performance requirements for multi-slot PUCCH transmissions. Furthermore, it removed the outdated BS type 2-O category from New Radio (NR) radiated performance requirements.
- CR on exclusion bands and spatial exclusion for IAB EMC Radiated Immunity testing TS 38.175CR0015
- CR to TS 38.175: Radiated emission, IAB TS 38.175CR0002
- CR to TS 38.175: Radiated emission, ancillary equipment TS 38.175CR0014
- CR to TS 37.145-2: Removal of BS type 2-O in radiated performance requirements for NR TS 37.145CR0152
- CR Modulation fallback for total power dynamic range in 37.145-2 clause 6.4.4.4.2.4 TS 37.145CR0210
- CR to TS 38.104: Corrections on rated carrier output power symbols TS 38.104CR0134
+ 3 more changes
In Release 17, specific updates to the EIRP function included corrections and clarifications for radiated requirements, such as a TDD off power radiated requirement correction and the definition of output power for NR repeaters within the base station specifications. The release also introduced the addition of Power Class 1.5 into the applicability of RF conformance test cases and made corrections to test applicability for FR2 standalone Enhanced Beam Correspondence EIRP conformance tests. Furthermore, it refined technical background related to additional power level calibration for radiated measurements.
- CR to TR 37.941: Addition of technical background related to additional power level calibration in subclause 7.3.1, 8.3 and 8.8 TS 37.941CR0040
- CR to 38.106: TDD off power radiated requirement correction TS 38.106CR0002
- CR to 38.106: Output power definitions for NR repeaters TS 38.106CR0004
- CR to TS 38.106 with updates and corrections for radiated part TS 38.106CR0020
- CR to TS 38.108: removal of NTN SAN output power accuracy requirements for the extreme test conditions, Rel-17 TS 38.108CR0011
- Adding test applicability for UE power saving test cases TS 38.522CR0083
+ 21 more changes
In Release 18, the EIRP-related specifications were updated with new radiated conformance requirements for mIAB-MT (Mobile-Integrated Access and Backhaul Mobile Termination) and for NTN (Non-Terrestrial Networks) uplink performance, specifically for PUSCH. The release also introduced new test case applicability and alignments for uplink MIMO, including for FR1 Carrier Aggregation and FR2, and added requirements for NB-IoT resource block power dynamic range in specific bandwidths.
- Big CR for BS demodulation requirements for Rel-18 MIMO in 38.104 TS 38.104CR0635
- BigCR on mIAB-MT radiated conformance requirement (TS38.176-2, Rel-18) TS 38.176CR0058
- CR on output power dynamic range for IoT NTN TS 36.108CR0010
- CR to 36.181: Test model correction for total power dynamic range requirements TS 36.181CR0004
- (LTE_NBIOT_eMTC_NTN_req-Perf)CR for TS36.181, Correction on Number of RX antennas in header row of tables for radiated demodulation test requirements TS 36.181CR0021
- (NR_FR1_lessthan_5MHz_BW-Core) CR to TS38.104 Add NB-IoT RB power dynamic range for 3MHz TS 38.104CR0681
+ 30 more changes
In Release 19, the key new developments for the EIRP function were the introduction of an expected EIRP mask core requirement for NCR (New Radio Carrier Aggregation Reference) and specific improvements related to the expected EIRP for operating band n104. These enhancements were detailed in updates to the core RF performance specifications for both base stations and user equipment, refining the requirements and test procedures for transmitter power characteristics.
- 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
- CR to TS 38.141-2 on clarification of LP-WUS power boosting TS 38.141CR0674
+ 18 more changes
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 |