Designing ultra-low-power GPS solutions for the IoT

Designing ultra-low-power GPS solutions for the IoT

Designing ultra-low-power GPS solutions for the IoT

u-blox’s latest white paper will help you hit the sweet spot between GPS performance, power consumption, and cost.

Particularly in consumer, industrial, and automotive tracking use cases, global navigation satellite system (GNSS) receivers were long considered power hogs. Back in 2010, a single band GNSS receiver in continuous tracking mode consumed just over 120 mW of power. By 2015, that number had come down to around 70 mW. Today, leveraging technological improvements, tracking applications can run on just 25 mW of power.

The past five years have seen the technology’s power autonomy climb to new heights. Today’s low-power GNSS receivers can track a greater number of satellite constellations, each on multiple frequency bands, to deliver greatly improved accuracies faster and with far less power. In some use cases, the GNSS receiver’s power demand can be reduced to a single-digit percentage of the end device’s power budget by relegating power-hungry computations to the cloud.

But meeting ambitious power consumption targets common in low-power asset tracking and related applications can be challenging. For one, there are many ways to integrate a GNSS receivers into an end-product, some of which are more power-efficient than others. Additionally, state-of-the-art GNSS receivers increasingly offer a range of settings that can be configured to optimize their power consumption while meeting use case-specific performance requirements.

Hitting the sweet spot for low-power GPS

In u-blox’s latest white paper on low-power GPS for tracking applications, they present an overview of essential design considerations that can bring down a GNSS receiver’s power demand to a mere fraction of that of a standard GNSS solution. Which of these design considerations applies to a specific use case will depend on a careful balancing of competing factors such as accuracy, dynamic performance, size, and cost.

Optimizing hardware choices and firmware settings

In the first part of the white paper, we focus on hardware-based strategies to develop long battery-life GPS trackers for five groups of use cases, including automotive trackers, sports watches, handheld devices, pet and kids trackers, and logistic goods trackers. In addition to obvious strategies, such as selecting low-power components, we present the pros and cons including a backup battery, a real-time clock, flash memory, and more.

But fine-tuning the hardware will only get you so far. Next, the white paper explores firmware-based approaches to cut power demand. Here, we focus on power-save modes, update rates, multi-GNSS support, and take a closer look at different forms of location services, including assisted GNSS (AGNSS) and cloud-based positioning.

Finally, we summarize our high-level guidance on design considerations the five chosen classes of use cases. These recommendations will give you a head start in discussions with the component supplier. Ultimately, however, the optimal settings can only be determined by considering the precise specifications of the target use case.

Today’s state-of-the-art GNSS receivers typically offer many means of optimizing their power consumption while meeting use case specific performance requirements. To find out precisely which of these design considerations and device configurations apply to your use case and get up to speed on how to balance the four competing factors of performance, size, power demand, and cost, read our white paper on low-power GPS for tracking applications.

Bernd Heidtmann

Product Manager, Product Strategy for Standard Precision GNSS, u‑blox

Courtesy of u-blox

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