CML Micro – Over 50 Years at the Heart of Critical Communications Standards

By Giuseppe Torres, Product Manager, CML Micro

Fifty years ago, critical communications relied on dependable voice analogue radio networks. Today, the sector is defined by global standards, sophisticated semiconductor technologies and increasingly complex hybrid communications architectures supporting emergency services, transport networks, utilities, defence organisations and critical national infrastructure worldwide.

Whether it is a firefighter inside a burning building, a railway controller responding to an incident, a utility operator restoring power after a major outage, a maritime crew operating in harsh conditions or first responders coordinating a large-scale emergency, reliable communications are fundamental to operational safety. In these environments, a loss of communication is far more than an inconvenience; it can compromise decision-making, delay emergency response and ultimately place lives at risk.

This is why professional mobile radio (PMR) and other mission-critical communications technologies continue to play such an important role. Unlike commercial consumer networks, they are engineered for resilience, security, predictable performance and dependable operation under the most demanding conditions, reflecting decades of technical innovation, rigorous standards development and a shared understanding that communications failure is simply not an option.

Few organisations have witnessed, and contributed to, the evolution of critical communications as closely as CML Micro. For more than five decades, the company has worked alongside equipment manufacturers, network operators, industry bodies, as well as end users to resolve some of the sector’s most complex pain points – from developing advanced RF and compound semiconductor technologies to actively contributing to standards development and spectrum regulation.

Standards are the foundation of reliable communications

The earliest two-way radio systems were largely proprietary, with interoperability between different organisations, vendors and infrastructure providers often problematic.

As networks expanded, regulation became essential to ensure systems could operate reliably across different platforms, protocols and frequency ranges. Frameworks such as TETRA (Terrestrial Trunked Radio), APCO Project 25 (P25) and Digital Mobile Radio (DMR) became internationally recognised approaches to security, resilience, spectrum efficiency and interoperability, laying the foundation of trust, resilience and reliability that mission-critical communication platforms continue to depend upon today.

Developing these standards has always involved more than technical specifications. It requires years of operational feedback, field testing and collaboration between equipment manufacturers, semiconductor suppliers, network operators, regulators and end users. Throughout that process, technical innovation has had to be balanced against the practicalities of real-world deployment, platform longevity and long-term operational support. Success depends not only on what is theoretically possible, but on what can be practically and reliably deployed and maintained in challenging real-world environments – one of the defining characteristics of the critical communications sector today.

CML Micro has contributed engineering expertise to this process through participation in ETSI, CEPT, TCCA, TIA TR-8, the dPMR Association, IEC, and IALA from the outset. The company played a key role in the development of TETRA 2 through ETSI Working Group 4, helping ensure new specifications are easily implemented within semiconductor and RF designs, and continues to champion the interests of innovative SMEs within ETSI. This combination of standards development, spectrum regulation and practical engineering knowledge has enabled CML Micro to bridge the gap between technical innovation and commercial deployment.

Technology evolution – from voice communications to hybrid networks

Advances in digital technology have fundamentally transformed mission-critical networks from voice-only systems into sophisticated communications platforms supporting encrypted voice, high-speed data, location services, telemetry and integrated operational workflows. The expansion of mobile broadband gave rise to data-rich applications such as live video, remote diagnostics, situational awareness tools.

These developments led to the emergence of Push-to-Talk over Cellular (PoC), extending communications beyond traditional radio infrastructure and creating new opportunities for broadband-enabled operations. However, these advances also introduced new challenges in meeting the stringent performance, reliability and resilience requirements of mission-critical communications.

There is little doubt that cellular technologies deliver significant advantages where high-bandwidth applications are priorities. However, many mission-critical operating environments, from transport corridors, ports and industrial sites to land-to-air operations, and dense urban areas, introduce stringent operational requirements that commercial cellular networks were never designed to satisfy. In these scenarios, assured coverage, infrastructure independence, predictable latency, network resilience and robust RF performance are not simply desirable characteristics, they are operational necessities.

As a result, the sector is rapidly moving towards hybrid communications architectures that combine the resilience of dedicated radio networks with the data capabilities of mobile technologies. Rather than replacing PMR, organisations are recognising that different communications technologies serve different operational priorities. The challenge is no longer deciding between dedicated radio and broadband but ensuring these increasingly sophisticated systems continue to guarantee optimal performance in harsh environments.

Why dedicated radio still matters

Despite the rapid growth of broadband communications, dedicated radio systems remain fundamental to mission-critical operations. Public safety agencies, transport operators, maritime services, utilities, industrial organisations and defence all operate in harsh environments where communications must remain available regardless of network congestion or challenging RF conditions.

This is where dedicated PMR technologies continue to offer significant advantages over 4G/5G networks. Systems based on TETRA and P25 were specifically engineered for operational resilience, supporting capabilities such as direct mode operation, prioritised traffic handling, deterministic latency, and dependable performance in congested spectrum conditions. Systems like dPMR and DMR can also provide many of these capabilities and may be configured to meet specific operational requirements, often offering a more cost-effective solution where the fill functionality of TETRA or P25 is not required.

The UK’s Emergency Services Network (ESN) programme illustrates the complexity of transitioning mission-critical communications towards mobile-based architectures. Even though cellular technologies undoubtedly introduce valuable new capabilities, replicating the resilience, predictability and operational assurance of mature PMR systems remains a significant engineering challenge.

Consequently, dedicated radio is increasingly viewed not as a legacy technology, but as an essential component of future communications strategies. The next generation of mission-critical communications will almost certainly combine dedicated radio and broadband technologies, making the challenge one of intelligent integration rather than outright replacement.

Supporting critical communications long-term not product cycles

The critical communications sector is facing growing commercial and operational pressures. Equipment manufacturers also face challenges of remaining cost competitive against emerging technologies.  As chip development costs continue to rise, many manufacturers are prioritising higher-volume, faster-growth markets with the prospect of stronger commercial returns if a design is adopted in a major manufacturer’s products. At the same time, mission-critical communications equipment designs are expected to have production lives far longer than mainstream commercial technologies, often with service lifecycles exceeding 15 to 20 years.

This creates significant challenges around component obsolescence, long-term supply continuity, lifecycle support, and the availability of specialist RF engineering expertise. Unlike consumer electronics markets, where rapid replacement cycles are both expected and commercially viable, critical communications infrastructure must remain stable, maintainable, and operationally dependable over decades of continuous service.

For organisations supporting this infrastructure, proven platforms are becoming increasingly valuable: long-term availability, stable RF performance, backwards compatibility and sustained engineering support carry as much weight as new functionality.

This ethos has shaped CML Micro’s approach to product development for many years. Devices such as the CMX994 RF Direct Conversion Receiver and CMX998 Cartesian feedback loop transmitter were developed specifically to meet the demanding performance, reliability and longevity requirements of mission-critical communications, reflecting an engineering philosophy centred on delivering robust, proven technologies that can be confidently deployed and supported throughout extended operational lifecycles.

What’s next for critical communications

Critical communications networks are entering a new phase of technological convergence, where dedicated radio, broadband connectivity, cloud-based applications and increasingly intelligent operational systems must operate seamlessly together to deliver resilient communications services.

The industry’s objective is no longer simply to introduce new capabilities, but to integrate these technologies without compromising the resilience, reliability and operational assurance that mission-critical users expect. Achieving that balance will require continued collaboration between standards bodies, semiconductor companies, equipment manufacturers, network operators and regulators.

This is precisely why engineering expertise such as that offered by CML Micro continues to play such a vital role. Organisations that actively contribute practical implementation experience into standards development are better placed to ensure future technologies remain grounded in the realities of deployment, certification and long-term operational support.

The next generation of mission-critical communications will therefore be defined not simply by technological innovation, but by the industry’s ability to evolve collaboratively while maintaining the trust, resilience and dependability that frontline users require.

Conclusion

Throughout its history, CML Micro has helped shape the evolution of critical communications through specialist RF expertise, long-term engineering commitment, and active participation in standards-led markets.  Alongside this, the company has continued to develop semiconductor technologies that meet the demanding performance, reliability and longevity requirements the sector depends on. Collectively, these strengths have enabled CML to contribute not only to advances in communications technology, but to the resilience and dependability of the systems that support critical operations worldwide.

As communications technologies continue to progress, the success of the critical communications sector will depend not simply on innovation, but on the engineering expertise, robust standards and close industry collaboration needed to deliver systems that remain trusted, resilient and fit for purpose, principles that have long underpinned CML Micro’s approach and will continue to guide its contribution to the next generation of mission-critical communications technologies and standards.

Appendix 1 illustrates CML Micros involvement in the development of critical communications standards

Standards Body	Document Reference	Outline Scope	CML Participation
ETSI ERM-WGDMR (Formerly TGDMR, RES02)	EN 300 086, EN 300 113, EN 300 219 EN 300 296, EN 300 341, EN 300 390, EN 300 471, EN 301 391,	Land Mobile: Core co-existence standards for spectrum access.	Current Rapporteur
ETSI ERMWGDMR	EN 301 783	Amateur Radio	Participant (chair)
ETSI ERMWGDMR	EN 301 166, EN 302 561,	Land Mobile: Core co-existence standards for spectrum access.	Originating author; current Rapporteur
ETSI ERMWGDMR ETSI TCCE04	EN 303 039	Multi-channel transmitters	Originating co-author; current Rapporteur
ETSI ERMWGDMR	EN 303 405	PMR446	Originating author; current Rapporteur
ETSI ERMWGDMR	EN 300 135, EN 300 433,		Participant (chair)
ETSI TC CCS (formerly TC TCCE, EP_TETRA and RES 06)	EN 300 392-2 EN 300 394-1	Core TETRA standards	Participant for TETRA Release 2 (WG4)
ETSI ERMWGDMR ETSI TCCE04	EN 303 758	Land Mobile: Core co-existence standards for spectrum access for TETRA.	Originating co-author; current Rapporteur
ETSI ERMWGDMR	TS 102 361	DMR	Participant (chair)
ETSI ERMWGDMR	TS 102 490 TS 102 658	dPMR	Participant (chair)
ETSI ERMWGDMR	TS 103 236	DCS/CTCSS	Originating co-author; current Rapporteur
CEPT/ECC PT SE21	Rec. 74-01 and various other documents	Spectrum Engineering	Participant
IEC	IEC-62287	AIS Class B	Participant
		VDES	Participant
TIA WG8	P25 family	APCO P25	Former Participant
NXDN Forum	NXDN family	6.25 kHz FDMA from Japan	Former Participant
dPMR Association	dPMR family	6.25 kHz FDMA from ETSI	Former Participant

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Courtesy of CML Micro