Do Water Meters Still Need External Transmitters?

By Igor Poliscuk

For decades, water metering followed a simple logic: install a mechanical meter, attach an external communication module (commonly referred to as a meter transmitter or endpoint), and connect the two with a wire. This architecture worked as intended, allowing utilities to digitize meter readings without replacing the meter itself. For its time, it was the right solution.

Today, however, expectations for transparency and reliability in water-metering infrastructure have risen. As a result, a fundamental question is emerging across the industry: if modern ultrasonic meters are already smart, why are we still adding intelligence outside the meter?

The Rise Of External Communication Modules

External communication modules became dominant during the early phases of AMR and AMI deployments. At that time, both utilities and contractors needed flexibility in protocols. Communication technologies were still evolving, and utilities wanted the option to switch networks without replacing the mechanical meter. External radio modules made this possible.

For its flexibility, this modular approach also suited contractors, who could visit a site and swap the radios for new ones without interfering with the meter itself.

At the time, the model made perfect sense. However, the flexibility came at a cost — it introduced complexity and maintenance costs.

The Hidden Complexity No One Talks About

What appears to be a simple and flexible system is, in practice, way more complex. And here we have a perfect example. Instead of a single ultrasonic smart meter, you have an architecture with multiple components:

• a mechanical meter
• an external communication module (meter transmitter/endpoint)
• connection wires
• separate battery systems
• two installation procedures (one for the meter and one for the transmitter)
• network repeaters

Each element adds extra steps for installation and maintenance, increasing the risk of errors and failures.

The Reliability Gap

The operational reality is straightforward: the more components a metering system contains, the more potential points of failure it introduces. Wires can break, get wet, or become damaged during maintenance. Meter transmitters bring separate batteries and extra installation steps, while repeaters add even more potential points of failure.

By contrast, modern integrated ultrasonic meters simplify operations: one device, one battery, a single-step installation, no moving parts, and manufacturer-tested reliability. And this is where the narrative takes a new direction — towards advanced integrated solutions.

Communication Has Evolved — Architecture Must Follow

As meters become smarter, the supporting network architecture must evolve too. Open protocols like LoRaWAN illustrate this shift: it offers higher penetration, better range, greater network capacity, and ecosystem flexibility without relying on proprietary repeaters (reducing dependence on repeater-based architectures).

The value of open standards goes beyond interoperability — they also provide resilience. AES-128 encryption is publicly documented and peer-reviewed, avoiding security through obscurity, reducing vendor lock-in, and supporting greater supply chain resilience.

By contrast, proprietary radios typically rely on black-box encoding, which can limit transparency and make external validation more difficult.

If infrastructure systems are to meet future needs, openness and security are essential — and this trend is increasingly reflected in modern AMI deployments.

Why The Market Is Moving Beyond External Radios

The market is clearly shifting away from standalone meter transmitters used in traditional AMR systems. All this happens because advanced solutions deliver real benefits: they improve efficiency, simplify installation, reduce lifecycle costs, decrease failure points, and increase data quality.

Market data reflects a structural shift in water-metering technology. According to Berg Insight, the number of water AMI endpoints in North America and Europe is expected to grow from about 66 million in 2024 to nearly 139.5 million by 2030, more than doubling in a few years. This growth reflects a transition from walk-by and drive-by AMR systems toward fixed-network AMI infrastructure, where communication is increasingly integrated directly into the metering device.

As these deployments expand, utilities increasingly adopt meters with integrated communication capabilities, reducing reliance on standalone meter transmitters that were commonly used in earlier walk-by and drive-by AMR systems.

From An Economics Perspective: One Device vs. Three

Legacy architecture typically includes a mechanical meter, a radio module, connection wiring, and additional mounting hardware used to secure the system in place.

In contrast, integrated architecture offers one ultrasonic smart meter with all the essential functions combined in a single device. In most cases, no repeaters or external antennas are needed. Only in harsh underground conditions, an external antenna might be added in order to extend the signal without adding a second powered device.

This comparison shows maturity — how advanced technologies may reduce structural complexity and simplify installation while maintaining network reliability and flexibility in challenging environments.

Questions Operators Should Ask

There are strategic questions designed for operators — and this isn’t about the brands or specific technologies. It’s about system architecture. Utilities and property operators should focus on the real metrics that drive operational cost and consider the following:

• How many components exist per metering point?
• How many batteries must be maintained?
• How many potential failure modes exist in the system?
• How many different hardware SKUs must be stocked?
• How many service visits are related to communication issues rather than meter performance?

The answers to these questions reveal the true cost and complexity of the infrastructure, highlighting why integrated, single-device solutions make strategic sense in today’s environment.

Are Meter Transmitters Approaching The End Of An Era?

There’s no doubt — external communication modules were necessary during the early stages of the digital transformation. It worked as intended at the right time and in the right conditions.

However, now the reality changes. Meters are intelligent, networks are open, penetration is stronger, security is high, and communication lives inside the smart meter. While external transmitters will continue to play a role in retrofit and legacy scenarios, their importance in new deployments is decreasing.

The industry doesn’t need clamp-on intelligence anymore. Instead, it increasingly prioritizes integrated reliability within the metering device. And as intelligence moves under the glass, the meter's external transmitter naturally begins to fade.

Igor Poliscuk is a notable figure in the IoT sector from Lithuania, Europe. With more than 15 years of experience in the IoT industry, he has gained deep knowledge and built a broad network, earning him a reputation as a professional expert. In recent years, Poliscuk has been driven by a focus on smart water management and demonstrating advanced solutions that can make a tangible impact on the submetering and utility businesses. As the CEO of Mainlink, he has been instrumental in deploying IoT technologies to optimize resource management and enhance property safety and efficiency.