Telecommunications Standards Summary - October 2025

Looking back at October 2025, the Telecommunications, Audio, and Video Engineering sector saw focused advances in electromagnetic compatibility (EMC) standardization. The month’s highlight was the publication of a single, yet significant, international standard—CISPR 16-1-4:2025—that updates the foundational requirements for radio disturbance and immunity measuring apparatus, particularly regarding antennas and test sites for radiated disturbance measurements.

Although this month’s publication count is modest, its technical depth and broad applicability make it essential for professionals seeking to maintain compliance, modernize measurement practices, and anticipate the sector’s evolving regulatory demands. This article provides a detailed retrospective overview, contextualizing the new edition within ongoing trends and outlining practical implementation considerations.

Monthly Overview: October 2025

October 2025 reflected a trend toward technical refinement and harmonization within the Telecommunications, Audio, and Video Engineering industry, specifically in the domain of EMC measurement infrastructure. The release of CISPR 16-1-4:2025—representing a comprehensive revision of the standard—demonstrates the sector’s sustained commitment to precision in radiated disturbance measurements spanning frequencies from 9 kHz to 18 GHz.

Rather than incremental changes across numerous documents, the period saw concentrated activity focused on a cornerstone standard, indicating a maturity and stabilization of core EMC testing methodologies. Compared to prior months, which may have featured broader or more fragmented updates, October’s targeted publication underscores the critical role of measurement repeatability, uncertainty management, and the compatibility of equipment for global interoperability.

This focus is emblematic of an overall sector direction emphasizing harmonized practices, reduced ambiguity, and enhanced test site validation—relevant both to manufacturing quality systems and regulatory conformity worldwide.

Standards Published This Month

CISPR 16-1-4:2025 – Antennas and Test Sites for Radiated Disturbance Measurements

Specification for radio disturbance and immunity measuring apparatus and methods – Part 1-4: Radio disturbance and immunity measuring apparatus – Antennas and test sites for radiated disturbance measurements

The fifth edition of CISPR 16-1-4, published in October 2025, delivers a comprehensive specification for the characteristics and performance of measurement equipment—spanning antennas and test sites—for evaluating radiated disturbances in the 9 kHz to 18 GHz frequency range. This standard forms a foundational component of international EMC testing, directly impacting manufacturers of telecom, audio, and video devices as well as compliance and test laboratories.

What the Standard Covers

This edition details specifications for the design, selection, calibration, and validation of antennas and test sites used in radiated disturbance measurements. This includes:

• Requirements for linearly polarized antennas (with specific guidance by frequency range)
• Procedures for validation and calibration of test sites, including open-area test sites (OATS), semi-anechoic chambers (SAC), and fully-anechoic rooms (FAR)
• Criteria for cable termination devices, including the introduction of the very high frequency line impedance stabilization network (VHF-LISN)
• Test methods for measurement repeatability, uncertainty evaluation, and site validation across distinct frequency bands
• Refined definitions and expanded terminology relevant to current measurement environments

Key Requirements and Specifications

Among its notable technical changes, CISPR 16-1-4:2025 incorporates:

1. Revised definitions: Enhanced clarity on core terms such as common mode absorption device (CMAD), reference ground, and new definitions related to VHF-LISN and TN‑C‑S power systems.
2. New device introduction: The VHF-LISN as a cable termination device, critical for high-frequency line impedance control.
3. Expanded site validation protocols: More robust acceptance criteria, site attenuation measurements, and uncertainty evaluation methodologies for various test site arrangements.
4. Alignment with drafting rules: Editorial updates for consistency across CISPR documentation, ensuring harmonization with IEC Guide 107 and related standards.

Who Needs to Comply

• Manufacturers and developers of telecommunications, broadcast, audio, and video equipment
• EMC and compliance testing laboratories, both independent and in-house
• Quality managers and regulatory officers responsible for product certification to international EMC standards
• System integrators and procurement specialists specifying measurement equipment or test facilities

Organizations integrating new or revised radios, digital interfaces, power systems, or cable assemblies within telecommunications or AV products will especially benefit by updating practices in line with this standard.

Broader Regulatory Context

As a 'basic EMC publication' per IEC Guide 107, CISPR 16-1-4:2025 is meant to be referenced by product-specific committees and serves as a common basis for type-testing and certification worldwide. Its revision addresses not only advances in technology and measurement sophistication but also supports global harmonization efforts and market access requirements.

Notable Features and Changes

• Revised term definitions for improved clarity (e.g., CMAD, reference ground)
• Introduction of VHF-LISN for cable termination at very high frequencies
• Addition of normative and informative Annexes clarifying site validation, uncertainty, and antenna factors
• Assurance of measurement repeatability and inter-laboratory consistency through detailed calibration and test protocols

Key highlights:

• Upgraded VHF-LISN device specification for improved high-frequency measurement
• Enhanced site validation and uncertainty evaluation methodologies
• Clearer, more consistent terminology for international application

Access the full standard:View CISPR 16-1-4:2025 on iTeh Standards

Common Themes and Industry Trends

October 2025’s standards landscape was characterized by a deepening emphasis on:

• Measurement repeatability: With precise guidance for calibration and validation, the sector continues to reduce sources of error in EMC testing
• Site validation rigor: The complexity and regulatory significance of OATS, SAC, and FAR sites remain central, with new protocols ensuring consistent outcomes across global laboratories
• Cable termination and connection interfaces: The addition of VHF-LISN requirements reflects expanding concerns about high-frequency disturbances associated with modern digital interfaces and increased system integration
• Harmonization and clarity: The editorial and procedural harmonization supports mutual recognition of compliance results and facilitates supply chain interoperability

This month’s developments are congruent with ongoing digitalization in the sector, increased use of high-frequency circuits, and tighter regulatory oversight of product emissions.

Compliance and Implementation Considerations

Given the impact of CISPR 16-1-4:2025, affected organizations should undertake the following steps to ensure ongoing compliance:

1. Review and update existing measurement practices: Align antenna types, calibration procedures, and site validation protocols with the new specifications—paying close attention to definitions and criteria for new devices like VHF-LISN and updated site validation methods.
2. Assess laboratory infrastructure: Evaluate current OATS, SAC, or FAR sites for conformity with the evolved site validation requirements and acceptance criteria.
3. Train personnel: Ensure measurement engineers, test personnel, and quality managers are aware of new terms, test procedures, and calibration mandates.
4. Coordinate with supply chain and certification partners: Since this standard serves as a foundational reference for product compliance, work with external labs and certification bodies to ensure mutual understanding of the updated requirements.
5. Implementation timelines: Organizations should monitor corresponding local or regional adoption timelines and consider grace periods or transitional arrangements as stipulated by their national committees or market access bodies.

Recommended resources for getting started:

• Conduct internal gap analysis against CISPR 16-1-4:2025
• Access full standard and associated technical documentation through iTeh Standards
• Participate in technical seminars or online briefings on EMC best practices
• Engage with product committees and industry associations for clarification of applicability

Conclusion: Key Takeaways from October 2025

The October 2025 publication of CISPR 16-1-4:2025 marks a pivotal advance for those involved in EMC testing within the Telecommunications, Audio, and Video Engineering sector. By delivering renewed clarity, incorporating robust site and antenna validation protocols, and addressing high-frequency cable termination challenges, this edition helps ensure the accuracy, repeatability, and international acceptability of radiated disturbance measurements.

For industry professionals, the implications are wide-ranging: staying abreast of these updates is vital not only for regulatory compliance but also for maintaining best-in-class product quality and market access. Organizations are encouraged to:

• Prioritize review of the new standard and update relevant test procedures
• Invest in retraining and infrastructure enhancements as needed
• Leverage harmonized practices to streamline conformity assessment and facilitate global trade

Staying current with standards such as CISPR 16-1-4:2025 solidifies your organization’s competitiveness and ensures enduring compliance amid a rapidly evolving technology and regulatory landscape.

Explore the details and secure the authoritative standard via iTeh Standards.