The Internet of Finns


Finland’s cellular LTE know-how and Norway’s ultra low power wireless experience have combined to create a low power cellular modem for the IoT

Success in the chip sector isn’t just about executing a carefully considered and resourced strategy, sometimes chance comes into play. 

In 2014, Nordic Semiconductor was working out the next step in its Internet of Things (IoT) strategy. Meanwhile, the high-tech workforce of Oulu, in Finland’s north, was dusting itself down after a round of rationalization by silicon vendors.

In parallel, the 3rd Generation Partnership Project (3GPP), a collaboration of telecoms standard associations, was finalizing
a specification that extended modem categories to include LTE products for low power IoT applications.

By early 2015 these three independent events had come together to kickstart a design project that culminated in the launch of Nordic Semiconductor’s nRF91 Series, a low power, ultra-compact cellular module suited to the unique demands of the IoT. 

Nordic built its reputation on proprietary ultra low power wireless connectivity and in 2010, Nordic’s expertise in this technology became part of the core specification for Bluetooth 4.0, a new version of the popular short-range RF open standard which included a Low Energy element. Later, Nordic’s nRF51 Series Bluetooth LE solutions found favour with thousands of manufacturers of IoT solutions, such as smart lights and smart locks, across the globe.

Search for talent
By 2014, the company was looking for experienced RF engineers to bolster its R&D team tasked with introducing a new generation of Bluetooth LE Systems-on-Chip (SoCs). News of the availability of a rare pool of talented cellular engineers just across the country’s border led to Nordic organizing a recruitment event in Oulu.

Over 200 engineers turned up, including Juha Heikkilä, a veteran 3G and 4G LTE engineer who had started his career with Nokia. When Nokia dropped out of cellular modem design in 2010, selling its assets to Renesas, Heikkilä went too. The pattern was repeated when Broadcom bought Renesas’ modem business for $164 million in 2013. In mid-2014, Broadcom decided to focus its investment elsewhere and closed the Oulu plant leaving Heikkilä looking for a new challenge.

He was joined at the Nordic recruitment event by dozens of engineers with similar backgrounds including some who had worked for Ericsson (which moved out of the business in late 2014). In short, the talent available represented the cream of the world’s cellular engineering expertise at that time.

“I’d been responsible for running 3G and 4G-modem design teams for years,” explains Heikkilä. “I was joined by four similarly-qualified colleagues at the recruitment event. We quickly realized that if Nordic was truly ambitious about its IoT strategy it needed to consider a long-range but low power wireless area network [LPWAN] solution to complement its Bluetooth LE products by enabling Cloud connectivity. Cellular technology was a perfect option.”

Bluetooth LE is ideal for local area networks (LAN) but its short-range and lack of TCP/IP Internet interoperability demands a ‘gateway’ — such as
a smartphone or Wi-Fi router — to send data to the Cloud. For IoT applications, gateways introduce complexity, cost, and (depending on the technology) can compromise reliability. In contrast, cellular technology is secure, reliable, and enables Cloud connectivity without a gateway.
According to companies such as telecoms equipment maker, Ericsson, cellular IoT will rapidly expand to power 75 percent of the 1.8 billion LPWAN-connected devices in service by 2023.

It turned out that Nordic and Heikkilä’s group had been thinking along similar lines about cellular IoT. Nordic’s senior management backed development of an LTE-based product line for IoT applications. By January 2015, Heikkilä, newly installed as Nordic’s Finland General Manager and reporting to Nordic’s CTO, Svein-Egil Nielsen, had assembled a team of 60 Finnish LTE experts and opened a dedicated Nordic office in Oulu. (The headcount today has risen to 165 of which all are engineers bar two administration staff.)

At around the same time the 3GPP formally released its specification for lower power category LTE. Later, as part of the subsequent Release 13, this became LTE category M1 (LTE- M) and narrow band (NB)-IoT. The intention was to remove complexity from the modem hardware and encourage development of low cost, low power devices for the LPWANs needed to service the IoT. The specification focused Nordic’s Finnish team’s efforts on specifically developing LTE-M and NB-IoT cellular products.

Vision into reality
LTE modems present big engineering challenges to design, put into production, and certify. The magnitude of the challenges makes cellular a business only a few companies can afford. In January 2015, the number of global teams that were capable
of designing a high-end LTE modem could be counted on the fingers of one hand. One of those teams now worked for Nordic.

“Our team comprises in part the engineers who developed one of the best high-end LTE modems on the market when they worked for Broadcom,” explains Heikkilä. “They have been working with LTE from
the very beginning.”

While LTE-M and NB-IoT modems are simpler than high-end, high data-throughput cellular units, there’s no getting away from the requirement for extensive LTE expertise when designing such products. According to Heikkilä, the expertise is even more vital for the lower category products because everything has to be highly-optimized to meet the constraints dictated by the specification.

The nRF91 Series is not a stripped down high-end modem. Some competitors have adopted the stripped-down approach, but Heikkilä explains that his preferred methodology is to design “from the ground up”.
“It’s a completely new product area. While you definitely need the high-end expertise, if the low power modem is based on a previous design
you can be led down a road that leads to compromises to meet the constraints of the specification,” says Heikkilä. “We wanted to embark
on the project with no pre-conceived ideas to marry innovation with experience and end up with a product that exceeds the specification’s requirements and offers customers flexibility to power any IoT application they can think of.”

One of the specification’s constraints is power consumption; the modems must be designed to run from small batteries for long periods. This is where Nordic’s Trondheim R&D team’s decade of experience in minimizing the power consumption of Nordic’s Bluetooth LE SoCs came into play. This experience, explains Heikkilä, compressed the project timescales. “We would have got there in the end,” he says, “but without that in-house expertise
it would have taken much, much longer and diverted resources away from the critical and intensive RF design.”

Extending cellular heritage
Designing a low power LTE modem is just the start. The cellular spectrum is licensed and regulated; this is an operational advantage because it ensures quality-of-service, coexistence rules, and security, but it also means products connecting with the networks must be certified by the cellular network carriers. Certification is a daunting prospect for companies entering the sector. Nordic eased some of the certification challenges with a single variant capable of running on all the cellular frequencies used across the globe.

However, as a company new to the carriers and integrators some questions were raised about Nordic’s ability to make the grade. But once the heritage of the Finnish cellular engineering team working for Nordic became clear, those doubts evaporated.

“The key to success isn’t just in making a good job of the engineering side of things,” says Heikkilä. “Yes, LTE engineering is very difficult, optimizing power consumption is very difficult, and component integration is very difficult, but what’s also very difficult is making sure the product can be manufactured in high volume using as little silicon as possible with very high yields.

“The nRF91 Series integrates radio, application processor, Flash and RAM memory, and power management on the same die.
This level of integration pushes the envelope of high volume, high-yield silicon production.”

While high-volume production is still some months away, the product’s development is very advanced and at a January 2018 event in Oslo, Nordic unveiled its nRF91 Series to the world.

The success of the nRF91 Series will see Finland’s cellular heritage — an essential foundation of the five billion smartphones now in circulation —live on as a key enabler of tomorrow’s IoT.

The best high-end LTE modems

Nordic’s cellular IoT R&D team comprises in part engineers who developed one of the best high-end LTE modems on the market