Description
A Transmission and Reception Point (TRP) is a fundamental architectural component within the 3GPP Radio Access Network (RAN), specifically defined from LTE (Rel-7) onwards and central to 5G NR. It represents a physical or logical point that handles the transmission and reception of radio signals over the air interface with User Equipment (UE). Conceptually, a TRP is associated with a set of geographically co-located or distributed antenna elements. In traditional macro-cell deployments, a TRP often corresponds to a single base station site or sector. However, in advanced architectures like Coordinated Multi-Point (CoMP), Distributed MIMO, and cloud RAN (C-RAN), a single UE's communication can be managed by multiple TRPs simultaneously, which may be physically separated but logically coordinated by a central unit (CU) or distributed unit (DU). This decoupling of the transmission/reception function from a monolithic cell site is key to network densification and flexibility.
From a technical perspective, a TRP is responsible for the physical layer processing of signals for a specific set of antenna ports. It handles tasks such as digital beamforming, precoding, modulation, and resource mapping for the downlink, and corresponding reception, demodulation, and channel estimation for the uplink. In the 5G NR context, a TRP is closely tied to the concept of a Synchronization Signal Block (SSB) and Channel State Information Reference Signal (CSI-RS), which are transmitted from specific TRPs to allow UEs to measure channel conditions, perform beam management, and report feedback. The gNB (5G base station) can consist of one or multiple TRPs. The 3GPP specifications define procedures for multi-TRP operation, where a UE can be configured with multiple Transmission Configuration Indicator (TCI) states, each linked to a different TRP, enabling robust transmission schemes like spatial diversity or increased data rates through multi-stream transmission.
The role of the TRP is critical for enabling key 5G features. It is the endpoint for beam-based communication, where each beam is effectively managed by a TRP. In integrated access and backhaul (IAB) networks, an IAB node acts as a TRP for its child nodes and UEs. For mobility, handovers and cell reselections are managed based on measurements of reference signals from different TRPs. The network can dynamically activate or deactivate TRPs based on traffic load, enabling energy savings. Furthermore, in network slicing, different slices can be served by specific sets of TRPs to meet diverse service requirements. The management and control of TRPs are handled by higher-layer protocols in the RAN, with interfaces like F1 and E1 in the 5G disaggregated RAN architecture facilitating communication between the CU and DUs that control the TRPs.
Purpose & Motivation
The concept of the TRP was introduced to abstract the physical transmission and reception functionality from the traditional monolithic cell concept. Earlier cellular systems were largely built around the idea of a cell, controlled by a single base station with a fixed set of co-located antennas. This model became limiting for advanced techniques like MIMO, CoMP, and network densification, where signals could originate from or be received by multiple geographically separated antenna arrays. The TRP provides a more granular and flexible reference point for these techniques.
Its creation was motivated by the need to support enhanced spectral efficiency and network capacity. By defining a TRP, 3GPP enabled specifications for schemes where multiple TRPs can serve a single UE (e.g., non-coherent joint transmission in CoMP), improving signal reliability at cell edges and overall throughput. It also facilitates the practical implementation of massive MIMO and beamforming, where a large antenna array is composed of multiple sub-arrays or panels, each potentially treated as a distinct TRP for management purposes.
In the evolution towards 5G and beyond, the TRP is foundational for ultra-reliable low-latency communication (URLLC) and enhanced mobile broadband (eMBB). Multi-TRP transmission allows for redundancy, reducing the probability of link failure. For industrial IoT and mission-critical services, simultaneous transmission from multiple TRPs to a single UE (PDCCH repetition, PDSCH repetition) enhances reliability. Thus, the TRP is not just a terminology update but a core architectural enabler for flexible, high-performance, and reliable radio networks.
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (126 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-7, normative work from Rel-15.
In Release 15, the TRP (Transmission and Reception Point) function was formally introduced with specific measurement procedures and clarifications. This included the definition of TRP measurement methods in Annex F of TS 37.145-2, along with corrections and clarifications on their applicability and terminology. Furthermore, technical reports like TR 37.843 were updated with details on angular step limits and calibration procedures for in-band TRP requirements.
- CR to TS 37.145-2: adding TRP measurement procedures in Annex F. TS 37.145CR0056
- CR to TS 37.145-2: Corrections related to TRP measurements in Annex F TS 37.145CR0094
- CR to TS 37.145-2: Corrections related to TRP measurements in Annex F TS 37.145CR0104
- CR to TS 37.145-2. Clarification of TRP methods applicability in Annex F TS 37.145CR0115
- CR to TS 37.145-2: Correction on usage of terms TRP and EIRP TS 37.145CR0124
- CR to TR 37.843: Editorial clean-up of TRP measurement section in sub-clause 10.8 TS 37.843CR0010
+ 7 more changes
In Release 16, key enhancements for the Transmission and Reception Point (TRP) function included the formal description and updated operational details for **multi-TRP operation**, along with corrections for aspects like the **reference TRP for DL-AoD and Multi-RTT measurement reports**. Furthermore, specific capabilities were introduced, such as a **capability bit for multi-CC simultaneous TCI activation with multi-TRP**, and procedures were refined, including the **coupling of TRP ID and Cell ID in measurement procedures**.
- CR for TS 38.104: Introduce PUSCH performance requirements at 30% throughput test point TS 38.104CR0168
- Correction to NR-ARFCN of the TRP TS 37.355CR0306
- Correction of reference TRP for DL-AoD and Multi-RTT measurement report TS 37.355CR0330
- Description of Multi-TRP operation TS 38.300CR0300
- Clarification on no support of CA, DC or multi-TRP with DAPS TS 38.300CR0307
- Correction on uplink transmission allowed without TA TS 38.300CR0343
+ 18 more changes
In Release 17, specific corrections and clarifications were made to the TRP (Transmission and Reception Point) function, primarily focusing on its role in positioning. These included corrections to the TRP Timing Error Group (TEG) and its associated timing error margin, as well as updates to the TRP Information Type Response Item IE for Positioning. Furthermore, the release introduced test updates for TRP and TRS (Tracking Reference Signal) and a correction related to multi-DCI multi-TRP operation alongside a new UE capability to limit PDCCH monitoring.
- Introduction of Small Data Transmission for MAC spec TS 38.321CR1198
- Missing transmission bandwidth configurations in F1AP TS 38.473CR1124
- Correction on transmission of SSR Assistance Data based on BDS B1C TS 37.355CR0485
- Correction to IAB-MT timing reference point in TS 38.174 TS 38.174CR0042
- Corrections for IIoT on simultaneous PUCCH and PUSCH transmission TS 38.300CR0477
- Simultaneous PUSCH and PUCCH transmissions of same priority on different inter-band cells [SimultaneousPUSCH-PUCCH] TS 38.306CR1013
+ 14 more changes
In Release 18, the TRP function was enhanced with new test configurations and requirements for TRS (TRP Reference Signal), including the introduction of PC3 talk mode requirements for TDD bands and the scaling of PC3 TRP requirements. Furthermore, Release 18 introduced support for a **Mobile TRP** capability, along with corresponding location information support for this mobile node.
- CR to TS 38.161 on New test configurations for Rel-18 TRP TRS TS 38.161CR0007
- CR to TS38.161 on PC3 scaling of the TRP requirement TS 38.161CR0008
- CR to TS 38.161 on Rel-18 FR1 TRP TRS requirements TS 38.161CR0014
- CR to TS 38.161 on introduction of PC3 talk mode TRP requirements for TDD bands TS 38.161CR0017
- Introduction of RedCap UE MBS Broadcast reception [RedcapMBS] TS 38.300CR0753
- Introduction of Mobile TRP TS 38.305CR0155
+ 45 more changes
In Release 19, the advancements for the TRP (Transmission Reception Point) function included the introduction of an alternate TRP and TRS test procedure specifically designed for XR devices and the addition of a split measurement grids method for TRP/TRS measurements. These updates also brought new test cases for transmitter power during simultaneous transmission to multiple directions and refined TRP TRS test requirements for Size 2 UEs. Furthermore, improvements were made to TRP measurement procedures in the relevant technical specification annexes.
- CR to TS 37.145-2: implementation of the preferred test method and TRP annex improvements TS 37.145CR0415
- CR to TS 38.141-2: Improvements on Annex I - TRP measurement procedures TS 38.141CR0701
- CR to TS38.161 for an alternate TRS and TRP test procedure for XR devices TS 38.161CR0025
- CR for split measurement grids method for TRP/TRS measurements TS 38.161CR0027
- CR to TS 38.161 on Rel-19 FR1 TRP TRS requirements TS 38.161CR0030
- CR to TS 38.176-2: Improvements on Annex I - TRP measurement procedures TS 38.176CR0100
+ 12 more changes
Explore further
Broader topics and technologies where TRP plays a role.
Defining Specifications
3GPP specifications that define or reference TRP, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.700 vk00 | XR Services Application Enablement Layer | Rel-20 |
| TS 25.144 vb20 | UE OTA Antenna Performance Requirements | Rel-11 |
| TR 25.914 vj00 | 3G UE Radio Performance Test Methods | Rel-19 |
| TS 34.114 vc20 | Radiated Performance Test Procedure for UE/MS | Rel-12 |
| TS 36.108 vj10 | Satellite Access Node RF Requirements | Rel-19 |
| TS 36.181 vj30 | E-UTRA RF Test Methods for Satellite Access Node | Rel-19 |
| TS 37.105 vj10 | AAS Base Station Transmission & Reception Requirements | Rel-19 |
| TS 37.144 vj00 | UE OTA Antenna Performance Requirements | Rel-19 |
| TS 37.145 vj10 | AAS Base Station Conducted Conformance Testing | Rel-19 |
| TS 37.355 vj20 | LTE Positioning Protocol (LPP) | Rel-19 |
| TS 37.544 vg70 | UE Radiated Performance Test Procedures | Rel-16 |
| TR 37.843 vf70 | AAS BS Radiated RF Requirement Background | Rel-15 |
| TR 37.902 vj00 | OTA TRP/TRS Measurement for LTE Terminals | Rel-19 |
| 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 38.115 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 38.176 vj20 | IAB Conformance Testing Specification | Rel-19 |
| TS 38.181 vj10 | NR Satellite Access Node RF Testing | 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 38.306 vj00 | NR UE Radio Access Capability Parameters | Rel-19 |
| TS 38.321 vj00 | NR MAC Protocol Specification | Rel-19 |
| TS 38.455 vj10 | NR Positioning Protocol A (NRPPa) | Rel-19 |
| TS 38.473 vj10 | 5G F1 Application Protocol (F1AP) | 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 38.771 vj00 | FR2-1 OTA Testing for STxMP UEs | Rel-19 |
| TR 38.801 ve00 | Study on new radio access technology: Radio access architecture and interfaces | Rel-14 |
| TR 38.803 ve40 | Study on Coexistence and RF Feasibility for 5G NR | Rel-14 |
| TR 38.808 vh00 | Study on NR above 52.6 GHz to 71 GHz | Rel-17 |
| TS 38.809 vg60 | IAB Radio Transmission & Reception Background | Rel-16 |
| TR 38.810 vg70 | NR OTA Test Methods Study | Rel-16 |
| TR 38.815 vf10 | NR Frequency Range 24.25-29.5 GHz Study | Rel-15 |
| TS 38.817 | 3GPP TR 38.817 | Rel-7 |
| TR 38.825 vg00 | Study on NR Industrial IoT | Rel-16 |
| TR 38.828 vg10 | CLI and RIM for NR | Rel-16 |
| TR 38.834 vh20 | NR FR1 TRP/TRS Test Methodology | Rel-17 |
| TS 38.843 vj00 | Study on AI/ML for NR Air Interface | Rel-19 |
| TS 38.856 vg00 | Study on local NR positioning in NG-RAN | Rel-16 |
| TR 38.857 vh00 | Study on NR Positioning Enhancements | Rel-17 |
| TR 38.858 vi20 | Technical Report on Evolution of NR Duplex Operation | Rel-18 |
| TR 38.864 vi10 | Technical Report on Network Energy Savings for NR | Rel-18 |
| 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 38.884 vi20 | Technical Report | Rel-18 |
| TR 38.889 vg00 | NR-based access to unlicensed spectrum study | Rel-16 |
| TR 38.900 vf00 | Channel Model Study for >6 GHz | Rel-15 |
| TR 38.901 vj10 | Channel Model for 0.5-100 GHz | Rel-19 |
| TR 38.903 vj00 | Test Tolerances & Measurement Uncertainties | Rel-19 |
| TR 38.922 vj20 | Study on IMT Parameters for NR in Higher Bands | Rel-19 |