BS

Base Station

Radio Access Network →
Introduced in R99 Also in: User Equipment

BS is the network element that provides radio coverage and connectivity to mobile devices in a cellular network, managing radio resources and serving as the critical link to the core network.

Category
Radio Access Network
Introduced
R99
Where
Radio Access Network › NG-RAN (5G)
Also touches
1 segments
Specifications
172 specs
BS Description Purpose Detected Changes Specifications

Description

A Base Station (BS) is a fundamental component of the Radio Access Network (RAN) in 3GPP systems, responsible for establishing and maintaining wireless communication links with User Equipment (UE) within its coverage area, known as a cell. It performs critical functions such as radio signal modulation/demodulation, channel coding/decoding, power control, handover management, and scheduling of radio resources. The BS interfaces with the core network via backhaul links (e.g., to a Mobile Switching Center in 2G/3G or to a Next Generation NodeB/gNB in 4G/5G architectures) and with neighboring BSs for coordination and mobility support.

Architecturally, a BS comprises several key subsystems: the Radio Unit (RU) handles analog radio frequency (RF) transmission and reception, including power amplification and filtering; the Baseband Unit (BBU) processes digital baseband signals, implementing physical layer protocols, error correction, and resource scheduling; and the control and management unit oversees operation, administration, and maintenance (OAM) functions. In modern deployments, such as 5G, these components may be disaggregated into centralized (CU), distributed (DU), and radio (RU) units under the Open RAN (O-RAN) framework to enhance flexibility and scalability.

The BS operates within defined RF bandwidths, with specific frequency edges (lower and upper) that determine its operational spectrum. It manages multiple access technologies (e.g., FDMA, TDMA, CDMA, OFDMA depending on the generation) to serve multiple UEs simultaneously. Key protocols implemented include the Radio Resource Control (RRC) for connection management, Packet Data Convergence Protocol (PDCP) for header compression and encryption, Radio Link Control (RLC) for segmentation and ARQ, and Medium Access Control (MAC) for scheduling and multiplexing. The BS also performs measurements for link quality, interference management, and supports mobility procedures like handovers, ensuring seamless service continuity as UEs move across cells.

In the broader network ecosystem, the BS acts as the primary point of radio access, translating core network commands into over-the-air transmissions and vice versa. It enforces quality of service (QoS) policies, manages spectrum efficiency, and supports advanced features like carrier aggregation, massive MIMO, and beamforming in later releases. Its performance directly impacts network capacity, coverage, and user experience, making it a focal point for optimization and innovation in cellular standards.

Purpose & Motivation

The Base Station exists to enable wireless mobile communication by providing the necessary infrastructure to connect User Equipment to the telecommunications network. It solves the fundamental problem of extending network services over a geographic area without wired connections to every device, facilitating mobility and ubiquitous access. Historically, early cellular systems (like 1G) used base stations with limited capabilities, but as demand grew for higher data rates, better spectral efficiency, and more advanced services, the BS evolved to address these needs through digital signal processing, smarter resource management, and support for packet-switched data.

Motivated by the limitations of previous approaches—such as analog systems' susceptibility to interference and inefficiency, or early digital systems' inability to handle high-speed data—the BS in 3GPP standards was designed to be a scalable, programmable platform. It enables multiple access schemes, adaptive modulation and coding, and sophisticated antenna technologies to maximize throughput and reliability. The BS also addresses operational challenges like network planning, interference coordination, and energy efficiency, becoming a key enabler for generations from GSM (2G) to 5G and beyond.

Detected Changes Across Releases

from 3GPP Change Requests

Specific changes extracted from the „Change history“ tables of 3GPP specifications (160 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.

Rel-15 35 changes

In Release 15, new Base Station capabilities were introduced, including a BS IC (Interference Cancellation) receiver with defined conformance tests and demodulation requirements. The release also added support for higher order modulation with Downlink 1024QAM and introduced specific BS demodulation requirements for enhanced further enhanced Machine-Type Communication (eFeMTC). Furthermore, BS requirements were updated for features like the subPRB (sub-PRB) operation and the formal introduction of Microcell and Picocell NB-IoT Base Stations.

  • 36.104 CR for BS IC receiver - Definitions TS 36.104CR4692
  • 36.104 CR for BS IC receiver - Demodulation tests TS 36.104CR4693
  • 36.104 CR for BS IC receiver - FRC definitions TS 36.104CR4694
  • CR on BS RF requirments for DL 1024QAM in TS 36.104 TS 36.104CR4754
  • Introduction of BS demodulation requirements for eFeMTC (TS36.104) TS 36.104CR4805
  • 36.141 CR for BS IC receiver - Connection diagram TS 36.141CR1057

+ 29 more changes

Rel-16 18 changes

In Release 16, the Base Station (BS) specifications were expanded to introduce new performance requirements for critical 5G features. This included specific BS demodulation requirements to support Ultra-Reliable Low Latency Communications (URLLC), the 2-step Random Access Channel (RACH) procedure, and operation in Unlicensed spectrum (NR-U). These updates defined the BS's capabilities for handling new physical channels like PUSCH with repetitions and various PUCCH formats under these advanced scenarios.

  • CR to TS 38.104: Introduction of NR-U into BS core specification TS 38.104CR0239
  • CR for 38.104: Ultra high reliability BS demodulation requirements TS 38.104CR0243
  • CR for 38.104: Low latency BS demodulation requirements TS 38.104CR0244
  • CR to TS 38.104 BS demodulation requirements for 2-step RACH TS 38.104CR0245
  • CR on BS demodulation requirements for 2-step RACH for FR2 TS 38.104CR0248
  • CR to TS 38.104: Addition of BS performance requirements for URLLC PUSCH repetition Type A TS 38.104CR0249

+ 12 more changes

Rel-17 33 changes

In Release 17, key Base Station enhancements included the introduction of 1024QAM modulation for NR FR1 conformance testing and the definition of a home class as a type of LA BS. The release also expanded BS RF conformance requirements to support an extension to 71 GHz and introduced specific performance and conformance criteria for NR-U (NR in Unlicensed Spectrum) base stations. Furthermore, it brought updates for NB-IoT BS performance requirements and refined BS channel bandwidth specifications per operating band.

  • Big CR for TS 36.104 for Rel-17 NB-IoT BS performance requirements TS 36.104CR4960
  • Big CR for TS 36.141 for Rel-17 NB-IoT BS conformance testing TS 36.141CR1338
  • CR for 37.141 on BS RF conformance testing for 1024QAM for NR FR1 TS 37.141CR0997
  • Big CR on FR2 HST BS demodulation requirement for TS 38.104 TS 38.104CR0379
  • CR to 37.104: Correction of NR bands for MSR BS TS 37.104CR0947
  • CR to 37.141: Correction of NR bands for MSR BS TS 37.141CR0986

+ 27 more changes

Rel-18 39 changes

In Release 18, key Base Station enhancements included introducing new operational capabilities for LTE and NR base stations in non-terrestrial networks, specifically for High Altitude Platform Station (HAPS) and Aeronautical Telecommunications (ATG) systems. The release also defined new BS types like the FR2 home class Local Area BS and clarified performance and RF requirements for Multi-Band (MB) and Multi-Standard Radio (MSR) base stations, particularly regarding operating band unwanted emissions and demodulation for advanced MIMO. These updates expanded the operational scenarios and refined the technical requirements for next-generation base stations.

  • (TEI18) 36.104 CR to introduce LTE bands for HAPS BS [LTE_HAPS_B34] TS 36.104CR5003
  • (TEI18) 36.141 CR to introduce LTE bands for HAPS BS [LTE_HAPS_B34] TS 36.141CR1410
  • CR for TS 38.104 on adding RF requirements for ATG BS TS 38.104CR0543
  • (NR_ATG-Perf) BigCR to TS 38.104 Introduction of demodulation performance requirements for NR ATG BS TS 38.104CR0565
  • (NR_ATG-Core) CR for TS 38.104 on adding RF requirements for ATG BS TS 38.104CR0566
  • Big CR for BS demodulation requirements for Rel-18 MIMO in 38.104 TS 38.104CR0635

+ 33 more changes

Rel-19 35 changes

In Release 19, key Base Station enhancements include new RF and demodulation performance requirements for SBFD-capable (Subband Full Duplex) Base Stations and for BS supporting ATG (Air-to-Ground) communications with carrier aggregation. The release also introduces BS demodulation requirements using the MMSE-IRC (Minimum Mean Square Error - Interference Rejection Combining) receiver and finalizes the removal of legacy UTRA TDD specifications from Multi-Standard Radio (MSR) Base Stations.

  • CR to TS 38.104: Introduction of Rel-19 ATG BS supporting CA TS 38.104CR0728
  • CR to TS38.104 to introduce BS RF requirement for SBFD-capable BS TS 38.104CR0729
  • CR on 38.104: BS demodulation performance requirements for MMSE-IRC TS 38.104CR0719
  • BigCR to TS38.104 Introduce the BS demodulation requirement for Rel-19 ATG TS 38.104CR0762
  • Big CR on PUSCH requirement for SBFD-capable BS in 38.104 TS 38.104CR0768
  • BigCR Rel-19 NR BS MMSE-IRC in 38.141-2 TS 38.141CR0661

+ 29 more changes

Explore further

Broader topics and technologies where BS plays a role.

Defining Specifications

3GPP specifications that define or reference BS, 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 23.085 vj00 Closed User Group (CUG) Supplementary Service Stage 2 Rel-19
TS 23.107 vj00 UMTS QoS Framework Rel-19
TS 23.171 v1300 LCS Stage 2 Specification for UMTS Rel-4
TS 23.207 vj00 End-to-End QoS Framework for GPRS Rel-19
TS 23.228 vj50 IMS Stage-2 Service Description Rel-19
TS 23.700 vk00 XR Services Application Enablement Layer Rel-20
TS 23.815 v1500 IMS Charging Implications Rel-5
TR 23.910 v1400 UMTS Circuit Switched Bearer Services Overview Rel-5
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 25.111 vj00 LMU RF Characteristics for UTRA FDD Rel-19
TS 25.116 vj00 LCR TDD Repeater RF Characteristics 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 25.142 vj00 UTRA TDD Base Station RF Test Methods Rel-19
TS 25.143 vj00 UTRA FDD Repeater RF Test Requirements Rel-19
TS 25.201 vj00 UTRA Physical Layer General Description Rel-19
TS 25.212 vj00 UTRA FDD Layer 1 Multiplexing & Channel Coding Rel-19
TS 25.222 vj00 UTRA TDD Multiplexing & Channel Coding Rel-19
TS 25.816 v800 UMTS 900 MHz RF Requirements Study Rel-8
TS 25.820 v820 3G Home NodeB Study Report Rel-8
TS 25.821 v800 UMTS1500 Work Item Technical Report Rel-8
TR 25.914 vj00 3G UE Radio Performance Test Methods Rel-19
TR 25.996 vj00 3GPP-3GPP2 Spatial Channel Model Specification Rel-19
TS 28.662 vj10 Generic RAN Network Resource Model (NRM) IRP IS Rel-19
TS 28.663 vj00 Generic RAN NRM IRP Solution Set Definitions Rel-19
TS 28.702 vj00 Core Network NRM IRP Information Service Rel-19
TS 29.007 vj00 PLMN-PSTN/ISDN Interworking Requirements Rel-19
TS 29.109 vj00 GAA Bootstrapping Interfaces (Zh, Dz, Zn, Zpn) Rel-19
TS 32.240 vj40 Charging Management Architecture & Principles Rel-19
TS 32.250 vj00 Circuit Switched Offline Charging Rel-19
TS 32.260 vj10 IMS Charging Management Rel-19
TS 32.272 vj00 Charging for Push-to-Talk over Cellular (PoC) Rel-19
TS 32.273 vj00 MBMS Charging Management Rel-19
TS 32.278 vj00 Monitoring Events Offline Charging Specification Rel-19
TS 32.632 vb00 Core Network Resources IRP: Network Resource Model Rel-11
TS 32.732 vb00 IMS Network Resource Model IRP: Information Service Rel-11
TS 32.792 vb10 Generic RAN Network Resource Model (NRM) IRP Rel-11
TS 32.796 vc00 Generic RAN NRM IRP Solution Set Definitions Rel-12
TS 32.826 va00 Study on Energy Savings Management in LTE/SAE Networks Rel-10
TS 32.835 vc00 HetNet Management Information Selection Rel-12
TS 32.856 vf00 Energy Efficiency Assessment for RAN OAM Rel-15
TR 33.969 vj00 Security for Public Warning System (PWS) Rel-19
TS 34.114 vc20 Radiated Performance Test Procedure for UE/MS Rel-12
TS 34.124 vj00 EMC Requirements for 3G UTRA Terminals 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 36.106 vj00 E-UTRA FDD Repeater RF Requirements 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 36.143 vj00 E-UTRA FDD Repeater RF Testing Rel-19
TS 36.714 3GPP TR 36.714 R99
TS 36.715 3GPP TR 36.715 R99
TS 36.716 3GPP TR 36.716 R99
TS 36.744 ve00 CBRS 3.5GHz Band Specification for US Rel-14
TS 36.747 ve00 Enhanced CRS and SU-MIMO IM Performance Requirements 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 36.789 vd00 LAA Multi-Node Coexistence Test Methodology Rel-13
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 36.800 v1900 Extended UMTS/LTE 800 MHz Band Support Rel-9
TS 36.811 va00 Adding 2 GHz LTE for ATC in North America Rel-10
TS 36.813 va10 L-Band LTE for ATC in North America Rel-10
TS 36.821 v1910 Extended UMTS/LTE 1500 MHz Band Support Rel-9
TS 36.825 vd00 Study on Additional LTE TDD Configurations Rel-13
TS 36.852 3GPP TR 36.852 R99
TS 36.853 3GPP TR 36.853 R99
TS 36.858 ve00 LTE 2.6 GHz SDL Band Technical Report Rel-14
TS 36.860 3GPP TR 36.860 R99
TS 36.863 vc00 CRS Interference Mitigation for Homogeneous Networks Rel-12
TS 36.878 vd00 LTE Performance Enhancements for High Speed Scenarios Rel-13
TS 36.884 vd10 MMSE-IRC Receiver Performance for LTE BS Rel-13
TS 36.899 3GPP TR 36.899 R99
TR 36.942 vj00 E-UTRA System Scenarios Specification Rel-19
TS 37.104 vj10 MSR Base Station RF Characteristics Rel-19
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 37.141 vj10 RF Test Methods for Multi-Standard Radio Base Stations Rel-19
TS 37.461 vj00 Iuant Interface Layer 1 Specification Rel-19
TS 37.544 vg70 UE Radiated Performance Test Procedures Rel-16
TS 37.716 3GPP TR 37.716 R99
TS 37.717 3GPP TR 37.717 R99
TS 37.718 3GPP TR 37.718 R99
TS 37.802 va10 MSR BS RF Requirements for Non-Contiguous Spectrum Rel-10
TS 37.810 vc20 Study on Base Station Specification Structure Rel-12
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 37.842 vd30 BS RF Requirements for Active Antenna Systems Rel-13
TR 37.843 vf70 AAS BS Radiated RF Requirement Background Rel-15
TS 37.862 vj00 Adding channel bandwidth in existing NR bands Rel-19
TS 37.863 3GPP TR 37.863 R99
TS 37.864 3GPP TR 37.864 R99
TS 37.865 3GPP TR 37.865 R99
TS 37.866 3GPP TR 37.866 R99
TS 37.872 vf10 Technical Report on SUL & LTE-NR DC with SUL Rel-15
TR 37.880 vh20 High-power UE for fixed-wireless/vehicle use Rel-17
TS 37.898 vj00 Rel-19 HPUE for EN-DC Band Combinations Rel-19
TR 37.900 vj00 Multi-Standard Radio (MSR) Base Station Requirements Rel-19
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
TR 37.941 vj20 RF Conformance Testing Background for Radiated BS 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 38.113 vj00 NR Base Station EMC Specification Rel-19
TS 38.141 vj20 NR Base Station RF Conformance Testing Part 1 Rel-19
TS 38.151 vj00 NR UE MIMO OTA Performance Requirements 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 38.191 vj00 NR Ambient IoT RF Characteristics Rel-19
TS 38.194 vj00 Ambient IoT Base Station RF Spec Rel-19
TS 38.551 vi30 User Equipment (UE) Multiple Input Multiple Output (MIMO) Over-the-Air (OTA) performance Rel-18
TS 38.716 3GPP TR 38.716 R99
TS 38.717 3GPP TR 38.717 R99
TS 38.718 3GPP TR 38.718 R99
TS 38.719 vj00 Rel-19 NR SUL Configurations and CA Band Combinations Rel-19
TS 38.746 vj00 High Power UE for NR Inter-band CA/DC Rel-19
TS 38.750 vj00 High Power UE for NR Inter-band CA/DC Rel-19
TS 38.753 vj00 Spatial Channel Model Study for NR Demodulation Rel-19
TS 38.761 vj00 MIMO OTA Performance Measurements for UE Rel-19
TS 38.762 vj00 Dynamic MIMO OTA Test Methodology for NR FR1 Rel-19
TS 38.774 vj00 Rel-19 LP-WUS/WUR RF Requirements TR 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
TR 38.803 ve40 Study on Coexistence and RF Feasibility for 5G NR Rel-14
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
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 38.819 vg00 Band n65 for New Radio Technical Report Rel-16
TS 38.826 vg00 NR Vehicle UE 2Rx Exception Study Rel-16
TS 38.827 vg80 NR MIMO OTA Radiated Metrics & Test Methodology Rel-16
TR 38.828 vg10 CLI and RIM for NR Rel-16
TR 38.830 vh00 NR Coverage Enhancements Study Rel-17
TR 38.841 vh00 High power UE for NR inter-band CA Rel-17
TR 38.842 vh00 High Power UE for NR CA with Multiple Bands Rel-17
TR 38.844 vi00 Efficient utilization of licensed spectrum Rel-18
TR 38.846 vi10 Technical Report Rel-18
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 38.860 vh00 NR; Study on Extended 600 MHz NR band Rel-17
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
TS 38.873 vg00 NR Band n48 Technical Report Rel-16
TR 38.877 vi10 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 38.899 vi00 Technical Report for High Power UE Rel-18
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 38.913 vj00 Next Gen Access Tech Scenarios & Requirements 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
TS 45.820 vd10 CIoT for Internet of Things Rel-13