Telecom EMC Standards Updated: November 2025 Brings Advances in

Telecom EMC Standards Updated: November 2025 Brings Advances in Connector Testing

The field of Telecommunications, Audio, and Video Engineering takes a significant leap forward with the publication of two critical updates to international standards in November 2025. Focused on electromagnetic compatibility (EMC) testing for metallic cables and connectors, these new standards provide updated, rigorous requirements for ensuring robust, interference-free communication networks. With these releases, industry professionals can expect better-defined methodologies for measuring transfer impedance, screening attenuation, and coupling attenuation—factors that are central to modern telecom system reliability.

Overview / Introduction

The Telecommunications, Audio, and Video Engineering sector sits at the heart of global connectivity, managing immense data streams while demanding the highest standards for performance and reliability. As systems become increasingly complex, ensuring electromagnetic compatibility (EMC) has never been more crucial. EMC standards govern how well equipment stands up to interference, maintaining system uptime and data integrity.

In November 2025, two major standards—the latest edition of IEC 62153-4-7:2021—have been published, bringing substantial updates for testing metallic connector assemblies using the triaxial tube in tube method. This article provides telecom professionals, quality managers, engineers, and compliance experts a comprehensive guide to these new EMC standards: what they require, their impact, and how to stay compliant.

Detailed Standards Coverage

IEC 62153-4-7:2021 - EMC Testing of Connectors and Assemblies (Triaxial Tube in Tube Method)

Metallic cables and other passive components test methods – Part 4-7: Electromagnetic compatibility (EMC) – Test method for measuring of transfer impedance Z_T and screening attenuation a_S or coupling attenuation a_C of connectors and assemblies – Triaxial tube in tube method

Scope and Application

IEC 62153-4-7:2021 provides the definitive test methodology for measuring surface transfer impedance, screening attenuation, and coupling attenuation of metallic connectors and cable assemblies using the "tube in tube" triaxial method. This standard applies principally to:

Mated screened connectors (particularly the cable-to-connector joint)
Coaxial, balanced, multipin, and multicore cable assemblies
Components used within telecommunications networks, RF/microwave systems, and data transmission infrastructure

Engineers and quality managers responsible for EMC compliance in cable assemblies and connectors across telecom, broadcasting, and critical infrastructure sectors will rely on these methods to ensure product reliability and regulatory conformity.

Key Requirements

IEC 62153-4-7:2021 describes an advanced test setup where a device under test (DUT) is placed inside a metallic tube, with or without an extension tube, forming a well-defined shielded environment. The:

Transfer impedance (Z_T) is measured to evaluate the shield's effectiveness against magnetic interference, especially at lower frequencies.
Screening attenuation (a_S) is tested for the assembly's capability to attenuate interference, crucial for high data rate and RF systems.
Coupling attenuation (a_C) quantifies the ability to suppress coupling of unwanted signals—vital for balanced or multipin systems.

Notably, the method is flexible for both short and long electrical components by varying tube length and test configuration. The new edition enhances procedures for low frequency and high frequency measurements, calibration, and detailed reporting, driving reproducibility and accuracy in EMC assessment.

Notable Changes from Previous Edition

This third edition of the standard makes comprehensive technical revisions, including:

Extension of coupling attenuation measurements to include unscreened connectors and assemblies
Enhanced procedures for testing at low frequencies (LFCA—Low Frequency Coupling Attenuation)
Application of a 20 dB/dec envelope curve for frequency sweeps and data interpretation
Mitigation techniques for higher order modes at frequencies beyond cut-off
Expanded annexes:
- Annex E: Informative guidance for direct measurement of screening effectiveness
- Annex F: Normative definitions and application of mixed mode S-parameters (critical for advanced VNA testing)
- Annex G: Normative details on required accessories for coupling attenuation measurement
- Annex H: Informative discussion on low frequency screening attenuation

Practical Implications

Organizations involved in manufacturing or qualifying cable assemblies and connectors for communications, broadcast, or data centers will need to:

Revise laboratory and field-testing procedures to align with the updated triaxial tube in tube methodology
Train technical staff on mixed mode S-parameter measurements using Vector Network Analyzers (VNA)
Update procurement specifications to require suppliers to meet or exceed the new screening and coupling attenuation benchmarks

Key highlights:

Modernized testing for transfer impedance and attenuation across wide frequency ranges
Normative mixed mode S-parameters enhance VNA-based testing precision
Clear pathway for evaluating both screened and unscreened assemblies

Access the full standard:View IEC 62153-4-7:2021 on iTeh Standards

IEC 62153-4-7:2021 (Amended) - Expanded EMC Capabilities and Implementation Guide

Expanded Scope and Purpose

The November 2025 consolidated edition of IEC 62153-4-7:2021 incorporates significant amendments (Edition 3.1), providing deeper technical coverage and aligning with advances in industry practice. This version explicitly:

Consolidates IEC 62153-4-7:2015/COR1:2016 and Amendment 1:2018
Integrates updated practices from IEC 62153-4-9:2018 (for advanced coupling attenuation)
Expands applicability to a broader range of connector and assembly types, ensuring future-proofing for evolving telecommunications infrastructure

New and Enhanced Technical Content

Major technical innovations in this release include:

Direct measurement of screening effectiveness for connectors and assemblies:
- Methods for both coaxial and balanced/multiconductor types
Emphasis on Mixed Mode Network Analysis:
- Use of virtual baluns and multiport VNAs for better accuracy and reduced setup complexity
Annex guidance and procedures:
- Annex G: Essential test adapters and termination schemes for precise attenuation measurement
- Annex H: Focused procedures for low frequency applications

Testing and Implementation

Single triaxial tube in tube test setup supports all measurements—reducing equipment and streamlining workflows
Recommends detailed calibration, reporting, and environmental control (testing at 23 ± 3°C)
Supports adaptability for both high-frequency and low-frequency environments (using extension tubes and matching impedance adapters)

Who Needs to Comply?

Telecom component manufacturers (cables, connectors, RF assemblies)
Systems integrators and installers for data centers, telecom networks, cable TV, broadcasting, and industrial communications
Certification bodies and compliance auditors

Key highlights:

Comprehensive update with mixed mode S-parameters and practical annexes
Applicable to both screened and unscreened connectors/assemblies
Streamlined approach to EMC compliance—lab-tested and field-ready

Access the full standard:View IEC 62153-4-7:2021 on iTeh Standards

Industry Impact & Compliance

The newly updated IEC 62153-4-7:2021 standards mark a transformative step for telecommunications and audio-video engineering by establishing:

Greater credibility and traceability in EMC testing procedures
Increased assurance of network reliability by reducing susceptibility to external and internal EMI (electromagnetic interference)
Regulatory alignment: These standards help organizations align with regional and international EMC directives and market requirements
Procurement and supply chain consistency: Cables and connectors verified to the updated standards deliver confidence throughout project lifecycles

Compliance Timelines & Considerations

Organizations should review their EMC testing protocols immediately and plan for a transition period as required by customer or regulatory bodies
New project specifications and procurement contracts should reference Edition 3.1 explicitly from November 2025 forward
Early compliance reduces the risk of costly failures, production delays, or regulatory fines

Risks of Non-Compliance

Increased downtime and network instability due to unmitigated EMI
Regulatory penalties and barriers to international market access
Erosion of brand reputation and loss of customer confidence

Technical Insights

Common Technical Requirements

Adherence to the triaxial tube in tube test method, suitable across diverse frequency ranges (from low frequency up to 4 GHz and beyond with accessories)
Use of mixed mode S-parameter measurements, especially in environments deploying advanced networking equipment
Rigorous calibration and reporting protocols

Best Practices for Implementation

Start with environment assessment: Control temperature and ambient noise for repeatable results
Train staff in mixed mode VNA operation and modern balun usage
Regularly audit sample preparation and adapter quality
Document and retain detailed test reports for third-party verification and regulatory review
Collaborate with supply partners to ensure end-to-end compliance in the full assembly chain

Testing and Certification

Ensure equipment (VNAs, test jigs, baluns) meets minimum performance requirements stated in the annexes
Follow the envelope curve procedures for frequency sweeps to fully characterize attenuation
Consider third-party certification for critical projects or where regulatory mandates apply

Conclusion / Next Steps

The November 2025 publication of IEC 62153-4-7:2021 (including its consolidated edition) delivers the most comprehensive and actionable test framework yet for connector and cable assembly EMC performance. These advances help organizations mitigate risk, strengthen market position, and keep pace with evolving technical demands.

Recommendations for Organizations

Review and update EMC qualification procedures to reference the latest standard versions
Source and qualify products based on new requirements—especially for critical infrastructure or export markets
Invest in training and testing equipment to reflect methodological updates (notably mixed mode VNA measurement)
Monitor updates from iTeh Standards and the IEC, ensuring continuous compliance as technology evolves

Explore the full standards library and receive the latest updates at iTeh Standards

Stay ahead in the field of telecommunications, audio, and video engineering by integrating the November 2025 EMC standards into your compliance program. For detailed standards documents, expert guidance, and ongoing updates, refer to iTeh Standards—the trusted resource for global standards excellence.