E-UTRA

Enhanced Universal Terrestrial Radio Access

Radio Access Network →
Introduced in Rel-8 Also in: User Equipment

E-UTRA is the radio access technology defining the air interface for 4G LTE networks, providing high-speed data, low latency, and efficient spectrum use for mobile broadband services.

Category
Radio Access Network
Introduced
Rel-8
Where
Radio Access Network › NG-RAN (5G)
Also touches
1 segments
Specifications
111 specs
E-UTRA Description Purpose Related Classification Detected Changes Specifications

Description

Enhanced Universal Terrestrial Radio Access (E-UTRA) is the standardized radio access technology for the Long-Term Evolution (LTE) system, commonly known as 4G. It defines the complete air interface protocol stack and physical layer specifications between the User Equipment (UE) and the Evolved Node B (eNB). The architecture is simplified and flat compared to 3G UMTS, featuring a two-node design with the eNB handling all radio-related functions, including radio resource management, admission control, scheduling, and header compression. This design minimizes latency and improves efficiency. E-UTRA supports flexible bandwidths from 1.4 MHz to 20 MHz and utilizes advanced radio techniques like Orthogonal Frequency Division Multiple Access (OFDMA) for downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) for uplink. These techniques provide robustness against multipath fading and improve power amplifier efficiency in mobile devices. The technology also incorporates Multiple-Input Multiple-Output (MIMO) antenna systems, carrier aggregation, and advanced modulation schemes (up to 256-QAM) to achieve peak data rates exceeding 1 Gbps in later releases. Its role is central to delivering the high-speed, low-latency connectivity that defines the 4G experience, enabling services like HD video streaming, online gaming, and real-time communications. The specifications govern everything from physical channel structures and modulation to radio link control, packet data convergence, and radio resource control protocols.

Purpose & Motivation

E-UTRA was created to address the growing demand for mobile broadband data and the limitations of 3G UMTS/HSPA networks. Previous 3GPP technologies, while successful for voice and initial data, struggled with inefficient spectrum usage, higher latency, and architectural complexity that hindered scalability for high-speed data services. The primary motivation was to develop a radio access network that could significantly reduce cost-per-bit, provide vastly improved user experience with lower latency, and support seamless mobility for a fully IP-based network. It was designed from the ground up to support packet-switched traffic efficiently, moving away from the circuit-switched legacy of 2G/3G. This allowed operators to meet the explosive growth in data traffic driven by smartphones and internet applications. E-UTRA's flat architecture simplified network deployment and reduced signaling overhead, enabling more efficient handovers and better support for quality of service (QoS) differentiation for various applications.

Classification

Part ofLTE
Specific typesEN-DC
Related approachesOFDMASC-FDMA

Release Timeline

Detected Changes Across Releases

from 3GPP Change Requests

Specific changes extracted from the „Change history“ tables of 3GPP specifications (55 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.

Rel-15 29 changes

In Release 15, E-UTRA was fundamentally enhanced to enable operation connected to the 5G Core Network (5GCN), a key step in the evolution of the Evolved Packet System. This introduction required defining new procedures for inter-RAT handover and RRC redirection between E-UTRA/5GC and other access types, including NR. Furthermore, the release specified support for EN-DC and addressed UE capabilities and states like RRC_INACTIVE for E-UTRA operating with the 5G core.

  • Addition of NR bands to E-UTRA co-location blocking requirements TS 36.104CR4801
  • E-UTRA - NR Cell Resource Coordination TS 36.300CR1122
  • Introduction of E-UTRA connected to 5GCN TS 36.300CR1151
  • Introduction of E-UTRA connected to 5GCN TS 36.304CR0419
  • Capture NR agreements into 36.331 for E-UTRA connected to 5GC TS 36.331CR3475
  • Enabling E-UTRA capability triggered by emergency call TS 24.301CR2999

+ 23 more changes

Rel-16 11 changes

In Release 16, key enhancements for E-UTRA included improvements to mobility and voice fallback procedures, such as refining UE behavior for E-UTRA cell selection upon mobility from NR failure to support enhanced EPS voice fallback. The release also introduced the Preconfigured Uplink Resources (PUR) RNTI into E-UTRA related UE identities and defined the channel spacing between E-UTRA and NR carriers for improved coexistence. Furthermore, it provided clarifications on RRC processing delays for handover from E-UTRA to NR and corrected test models for higher-order modulations like 256QAM.

  • Re-enable E-UTRA capability upon change of voice domain preference TS 24.301CR3206
  • E-UTRA capability disabling with persistent EPS bearer context TS 24.301CR3429
  • Radio parameters for UE neither served by E-UTRA nor served by NR TS 24.587CR0113
  • Removal of CA bands list for E-UTRA TS 36.104CR4810
  • Removal of CA bands list for E-UTRA TS 36.141CR1188
  • Addition of PUR RNTI in E-UTRA related UE identities TS 36.300CR1297

+ 5 more changes

Rel-17 8 changes

In Release 17, enhancements for E-UTRA focused on operational clarifications and support for specific service scenarios. Key updates included refined procedures for E-UTRA cell selection during emergency service fallback and EPS fallback for emergency calls, as well as improved handling of E-UTRA capabilities triggered by RLOS calls and during handover. Additionally, provisioning for PC5 DRX configuration was extended to cover UEs operating in ProSe scenarios without being served by E-UTRA or NR access networks.

  • Clarification of E-UTRA capability handling TS 24.301CR3545
  • Provisioning PC5 DRX configuration at the UE for broadcast/groupcast when the UE is not served by E-UTRA and not served by NR TS 24.587CR0206
  • Correction on E-UTRA cell selection during emergency service fallback and EPS fallback for emergency call [CellSelection_EmergencyFallback] TS 38.331CR3548
  • Enabling E-UTRA capability triggered by RLOS call TS 24.301CR3691
  • Removing the ENs of E-UTRA capability handling TS 24.301CR3729
  • Adding the USIM file for the UE configuration parameter No E-UTRA Disabling In 5GS TS 24.301CR3748

+ 2 more changes

Rel-18 2 changes

In Release 18, the E-UTRA function saw specific updates including a clarification of the procedure for a UE disabling its E-UTRA radio access capability. Furthermore, conformance testing was enhanced with the introduction of a new E-UTRA slot-based transmission time interval (TTI) test model, designated as Test Model 2-1, for base station testing.

  • Clarification of the UE behavior disabling E-UTRA TS 24.301CR3912
  • CR to TS36.141[R18] E-UTRA slot TTI Test Model 2-1 TS 36.141CR1350
Rel-19 5 changes

In Release 19, the E-UTRA updates primarily focused on improving procedures for satellite E-UTRA cells, specifically aligning attach and service request processes with the term "S&F satellite E-UTRA cell." The release also introduced modifications to prevent the disabling of a UE's E-UTRA capability during specific detach procedures and updated cell re-selection behavior for certain UE types.

  • Update on re-enabling UE's E-UTRA capability TS 24.301CR4096
  • No E-UTRA capability disabling when detaching for eCall inactivity TS 24.301CR4193
  • Aligning attach and service request procedures with the term S&F satellite E-UTRA cell TS 24.301CR4382
  • S&F satellite E-UTRA cells usage TS 24.301CR4469
  • Applicability of E-UTRA - NR SA FR1 E-UTRA cell re-selection to higher-priority NR target cell for 2 Rx UE test case TS 38.522CR0647

Explore further

Broader topics and technologies where E-UTRA plays a role.

Topics
Spectrum & CoexistenceMEC (Edge Computing)LTE / LTE-AdvancedMIMO & BeamformingLawful InterceptSMS & Messaging
Technologies
LTE

Defining Specifications

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

SpecificationTitleRelease
TR 21.905 vj00 3GPP Technical Terms and Definitions Rel-19
TS 23.222 vj80 Common API Framework for 3GPP Northbound APIs Rel-19
TS 24.167 vj00 3GPP IMS Management Object Specification Rel-19
TS 24.301 vj60 NAS protocol for Evolved Packet System Rel-19
TS 24.312 vj00 ANDSF Management Objects Specification Rel-19
TS 24.587 vj30 V2X Services Protocols for 5G System Rel-19
TS 24.801 v810 CT1 SAE NAS Aspects for EPC Rel-8
TS 24.890 vg00 5G NAS Protocol for 5GS Stage 3 Rel-16
TS 25.133 vj00 UTRAN RRM Requirements for FDD Rel-19
TS 25.215 vj00 UTRA FDD Measurement Definitions Rel-19
TS 25.225 vj00 UTRA TDD Physical Layer Measurements Rel-19
TS 25.304 vj00 UTRA Idle Mode Procedures Specification Rel-19
TS 25.331 vj00 UTRAN RRC Protocol Specification Rel-19
TS 25.367 vj00 Home NodeB Mobility Procedures Rel-19
TS 25.413 vj00 Radio Access Network Application Part (RANAP) Rel-19
TS 25.423 vj00 UTRAN RNSAP Specification Rel-19
TR 25.912 vj00 Evolved UTRA and UTRAN Technical Report Rel-19
TS 25.913 v900 Evolved UTRA and UTRAN Requirements Rel-9
TS 28.627 vj00 SON Policy NRM IRP: Requirements Rel-19
TS 28.658 vj00 E-UTRAN NRM IRP Information Service Rel-19
TS 29.514 vj40 5G System; Policy Authorization Service; Stage 3 Rel-19
TS 31.121 vi50 UICC-terminal interface test specification Rel-18
TS 32.277 vj20 Charging Management for Proximity Services (ProSe) Rel-19
TS 32.762 vb70 E-UTRAN NRM IRP Information Service Rel-11
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 36.104 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 36.133 vj20 E-UTRA RRM Requirements Rel-19
TS 36.141 vj00 E-UTRA BS Conformance Testing Rel-19
TS 36.171 vj10 A-GNSS Minimum Performance Requirements for UE Rel-19
TS 36.181 vj30 E-UTRA RF Test Methods for Satellite Access Node Rel-19
TS 36.201 vj00 LTE Physical Layer General Description Rel-19
TS 36.214 vj00 E-UTRA Physical Layer Measurements Rel-19
TS 36.300 vj00 E-UTRAN Radio Interface Protocol Architecture Overview Rel-19
TS 36.302 vj00 E-UTRA Physical Layer Services Rel-19
TS 36.304 vj00 UE Idle Mode Procedures in E-UTRA Rel-19
TS 36.306 vj00 E-UTRA UE Radio Access Capability Parameters Rel-19
TS 36.321 vj00 E-UTRA MAC Protocol Specification Rel-19
TS 36.322 vj00 E-UTRA Radio Link Control Protocol Specification Rel-19
TS 36.323 vj00 PDCP Protocol Specification Rel-19
TS 36.331 vj00 LTE RRC Protocol Specification Rel-19
TS 36.360 vj00 LTE-WLAN Aggregation Adaptation Protocol Rel-19
TS 36.361 vj00 LWIP Encapsulation Protocol Specification Rel-19
TS 36.401 vj00 E-UTRAN Overall Architecture Description Rel-19
TS 36.414 vj00 S1 Interface User Plane Transport Rel-19
TS 36.424 vj00 X2 Interface User Plane Transport Protocols Rel-19
TS 36.445 vj00 M1 interface user plane protocol for MBMS Rel-19
TS 36.521 vj00 E-UTRA UE Conformance ICS Proforma Rel-19
TS 36.714 3GPP TR 36.714 Rel-8
TS 36.715 3GPP TR 36.715 Rel-8
TS 36.716 3GPP TR 36.716 Rel-8
TS 36.744 ve00 CBRS 3.5GHz Band Specification for US Rel-14
TS 36.750 ve10 Study on enhancement of VoLTE 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
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 36.829 vb10 Feasibility Study on LTE UE Interference Cancellation Rel-11
TS 36.852 3GPP TR 36.852 Rel-8
TS 36.853 3GPP TR 36.853 Rel-8
TS 36.855 vd00 E-UTRA Positioning Enhancements Study Rel-13
TS 36.860 3GPP TR 36.860 Rel-8
TS 36.867 vd00 LTE DL 4 Rx Antenna Port Study TR Rel-13
TS 36.894 vd00 Study on LTE Measurement Gap Enhancement Rel-13
TS 36.899 3GPP TR 36.899 Rel-8
TS 36.938 v900 E-UTRAN to 3GPP2/Mobile WiMAX Mobility Rel-9
TS 37.106 vj00 UE RF Requirements for Shared Spectrum Access Rel-19
TS 37.107 vj00 RF Requirements for LAA and NR-U Base Stations 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 37.171 vj00 UE Positioning Performance Requirements Rel-19
TS 37.320 vj00 Minimization of Drive Tests (MDT) Overview Rel-19
TS 37.355 vj20 LTE Positioning Protocol (LPP) Rel-19
TS 37.544 vg70 UE Radiated Performance Test Procedures Rel-16
TS 37.571 vj00 UE Conformance for Positioning Rel-19
TS 37.716 3GPP TR 37.716 Rel-8
TS 37.717 3GPP TR 37.717 Rel-8
TS 37.718 3GPP TR 37.718 Rel-8
TS 37.719 vj00 3GPP TR 37.719: Dual Connectivity Band Combinations Rel-19
TS 37.863 3GPP TR 37.863 Rel-8
TS 37.872 vf10 Technical Report on SUL & LTE-NR DC with SUL Rel-15
TR 37.901 vf10 UE Application Layer Data Throughput Performance Rel-15
TR 37.902 vj00 OTA TRP/TRS Measurement for LTE Terminals Rel-19
TS 38.104 vj20 NR Base Station RF Requirements Rel-19
TS 38.133 vj20 5G UE Radio Requirements for RRC_IDLE Mobility 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 38.171 vj10 5G A-GNSS UE Positioning Requirements 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 38.191 vj00 NR Ambient IoT RF Characteristics Rel-19
TS 38.201 vj00 NR Physical Layer General Description Rel-19
TS 38.304 vj00 UE RRC_IDLE and RRC_INACTIVE Procedures Rel-19
TS 38.331 vj00 NR Radio Resource Control (RRC) Protocol Specification 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 38.717 3GPP TR 38.717 Rel-8
TS 38.718 3GPP TR 38.718 Rel-8
TS 38.719 vj00 Rel-19 NR SUL Configurations and CA Band Combinations Rel-19
TR 38.846 vi10 Technical Report Rel-18
TS 38.870 vj20 Enhanced OTA Test Methods for NR FR1 TRP/TRS Rel-19
TS 38.873 vg00 NR Band n48 Technical Report Rel-16
TR 38.889 vg00 NR-based access to unlicensed spectrum study Rel-16
TR 38.892 vi00 Technical Report Rel-18
TS 43.129 vj00 PS Handover in GERAN A/Gb and GAN Modes Rel-19
TS 48.018 vj00 BSS-SGSN Interface for GPRS Control Rel-19
Patrick Zandl

About the author: Patrick Zandl (b. 1974)

Telecommunications specialist, technology journalist (founder of the Mobil server), and developer who has been running since 2025 — the largest Czech-language resource on AI-assisted programming. Formerly Chief Wizard Architect at Prusa3D and head of development for Turris at CZ.NIC; currently a consultant and instructor on AI implementation in companies.

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