Enabling connected intelligence with low-power wide-area IoT connectivity

What you should know:

• Smart meters (e.g., gas and water) and other IoT devices need wide-area connectivity and multi-year battery life, where power consumption is the No. 1 design constraint driving product differentiation and selection.
• The Qualcomm E51 4G Modem-RF (QIM225) is purpose-built for LPWA IoT and ranks among the industry’s most power-efficient chipsets, supporting both eMTC (Cat-M1) and NB-IoT (Cat-NB2).
• In lab testing, the Qualcomm E51 4G Modem-RF delivers over 20% improved power efficiency compared to a leading, widely deployed competing chipset under defined conditions across PSM, low-power and active modes.

Intelligently connecting virtually everything around us is the vision that drives our work at Qualcomm Technologies, and it’s why we deliver a broad portfolio of purpose-built processing and connectivity solutions to meet the needs of diverse industries. 

A key focus area is low-power, wide-area (LPWA) connectivity designed for massive IoT deployments, where deep coverage and multi-year battery life are must-haves. This is where 3GPP-standardized LPWA technologies, narrowband IoT (NB-IoT) and enhanced machine-type communication (eMTC) aim to provide secure, globally interoperable connectivity for sensors, meters, trackers and other low-complexity IoT devices designed to operate for years on a single battery charge.

Power consumption drives differentiation and device selection

For most LPWA IoT applications, power consumption is often the primary design constraint: devices must deliver reliable coverage while having multi-year battery life, so every microamp counts in both low-power and active modes. Lower power extends operating life and reduces maintenance visits—cutting total cost of ownership (TCO)—and it can also enable smaller device form factors by requiring a smaller battery, improving overall aesthetics and sustainability.

That’s why the Qualcomm E51 4G Modem-RF leads in LPWA IoT, purpose-built to support both LTE Cat-M1 and Cat-NB2 with advanced power efficiency. It is developed to pair optimized power consumption with a compact, cost-effective design and rich peripheral support—helping customers build smaller, longer-lasting devices without compromising features.

Proven power efficiency: Qualcomm E51 4G Modem-RF vs. competitors

To quantify the advantage of Qualcomm E51 4G Modem-RF, we measured its power consumption in our lab across different power modes and representative use cases — then benchmarked those results against one of the most deployed eMTC and NB-IoT dual-mode chipsets, the Altair ALT1250.

Power measurements in sleep and active modes

Figure 3 below shows a comparison of the measured results of E51 versus ALT1250’s published specifications. The takeaway is clear: E51 delivers >20% power savings across all power modes, from ultra-low-power modes such as power save mode (PSM) to active transmit/receive states.

A closer look at the power performance curves

In extended discontinuous reception (eDRx) mode, the power profile is defined by both the baseline sleep current and the periodic paging wakeups. A closer look at the curves shows E51 implements power optimizations to reduce total energy in these low-power states — delivering 33% lower deep-sleep current and a more efficient wakeup mechanism with 67% shorter paging wakeup time. The result is smaller current spikes, which reduces overall battery draw while maintaining network reachability.

Real-world battery life simulations for IoT use cases

To go beyond lab measurements, we also ran system-level simulations based on our lab-measured power data to model end-to-end modem behavior in real-life operating profiles. These simulations translate sleep, wake, attach and transmit events into expected battery draw over time — showing how E51 can support battery life required by targeted use cases. In this study, we looked at the power profiles for three different low-power, wide-area use cases and their battery life requirements, including smart meters, remote sensors and asset trackers.

Smart meters: Water and gas meters typically have no main power, so they run on batteries and require ultra-long life — often 15+ years — with infrequent data transmission. For gas meters, paging monitoring is the primary battery drain, so the device commonly operates in eDRX; our simulation shows E51 reaching 15-year battery life with 7.5–11 Ah batteries, depending on the number of uplink transmissions per day. Similarly for water meters, the same 15-year target can be achieved with 0.3–4.5 Ah batteries, primarily by relying on PSM.

Remote sensors: In applications ranging from weather stations and agricultural sensors to grid-monitoring devices, the typical battery life target is up to five years of operation on a compact battery. With PSM and sending infrequent, one-way data uploads, the E51 can achieve this target with as little as 0.2–2.6 Ah of battery capacity, depending on payload size and reporting frequency. This is designed to support smaller device formfactors and can help reduce maintenance needs and total cost of ownership for large-scale remote deployments.

Asset trackers: These devices operate in challenging conditions, continuously uploading location data via GNSS, monitoring temperature, humidity, ambient light and motion through multiple onboard sensors, all while running in power-efficient eDRX mode. Despite this workload, the E51 can achieve up to three months of battery life on just 0.2–0.7 Ah of battery capacity, depending on upload frequency. 

Advancing massive IoT with ultra-low-power connectivity

At Qualcomm, high-performance wide-area connectivity and ultra-low-power design are part of our DNA. This is the foundation needed for delivering cutting-edge products like the Qualcomm E51 4G Modem-RF. Engineered for LPWA use cases, it helps devices run longer on a single battery charge, connect more reliably, and scale deployments more cost-effectively. We’re excited to help power what’s next in IoT, and we’ll continue to share updates as the ecosystem advances toward the vision of connecting virtually everything.

Go Deeper

How does the Qualcomm E51 4G Modem-RF achieve its power efficiency advantage?

We engineered the E51 to implement power optimizations that reduce total energy, resulting in smaller current spikes, reduced overall battery draw and maintained network reachability across PSM, eDRX and active modes. Our lab measurements showcased it delivers >20% better power efficiency than one of the most widely deployed eMTC and NB-IoT dual-mode chipsets on the market.

Are there more LPWA use cases and power efficiency insights beyond what's covered here?

Beyond smart meters, remote sensors and asset trackers, the LPWA IoT landscape continues to expand — and so does our work of pushing the boundaries of power-efficient connectivity. We'll continue sharing new benchmarks, use case coverage and ecosystem updates as the industry advances toward the vision of connecting virtually everything.