Riot starts with a claim to industry’s lowest power NB-IoT and eMTC baseband chip

Riot Micro's RM1000

Internet of Things (IoT) newcomer, Riot Micro is claiming that a radical design approach applying BLE/Wi-Fi architecture has delivered a new cellular IoT solution with cost/power levels that are characteristic of short-range wireless systems. Here Peter Wong, CEO, tells  Jeremy Cowan how Riot has reinvented itself as an IoT chipset maker.

Semiconductor start-ups are rare things these days. But Vancouver, Canada-based Riot Micro has made its IoT market debut with what it claims is the industry’s lowest power baseband modem chip for cellular IoT.

The company began life a decade ago working on LTE IP technology to licence to the general market. Then three years ago, in search of faster growth Riot changed direction and brought in Peter Wong as CEO. “We retooled and refinanced,” he tells IoT Now, “grew to about 30 people, and developed a chip for cellular IoT, based on LTE NB1 and eMTC specifications.”

Peter Wong, Riot Micro’s CEO

“Why IoT?” we ask.

“Because that’s where the majority of growth was. If you look at other cellular technologies – you know Cat 3, 4 , 5, 6 – as you go higher and higher for the smartphones and tablets of the world it gets harder and harder for a start-up to compete realistically. The key differentiators are integration and powerful processors with Snapdragons etc., and going up against the Qualcomms of the world didn’t make a whole lot of sense,” says Wong.

“When the standards started to evolve for M2M (machine-to-machine communications) it looked like there could be a significant inflexion point where the requirements changed significantly and where processor technology was not the King of the Game. It was about optimising for more performance and lower power, and of course much, much lower cost.”

“Cost being a huge factor in services with low ARPUs (average revenues per user),” IoT Now suggests.

“Exactly. That drove why we formed the team that we did. LTE is a relatively sophisticated protocol and technology relative to other wireless technologies like BLE and WiFi. But when you break it right down and look at NB1 and eMTC we felt there was a ton of simplification you could do technically and implementatikon-wise and speed-wise. When you’re driving 200kbps or even 1Mb you can take certain design approaches that are extremely power-efficient and really help drive the cost down. The memory is an example. We optimised the LTE protocol stack so that it only does NB1 and MTC. We could minimise the amount of memory required. Our protocol stack operates entirely within the memory within our chip.”

So the Riot Micro RM1000 has been built using Bluetooth Low Energy (BLE) and Wi-Fi architecture techniques to deliver a cellular IoT solution with the low power and cost levels of short-range wireless systems. The RM1000 is now being offered to module manufacturers and OEMs designing narrowband IoT (NB-IoT) and eMTC systems that can include automotive, asset management, home automation, industrial, point-of-sale, smart energy, and vending applications.

Asked who the company sees as its key rivals, Peter Wong tells IoT Now it would be companies like Sequans, and Altair which was acquired by Sony. (Also see: CLOE IoT tracker platform to be demoed at Mobile World Congress Americas, and Altair unveils miniature chipset platform designed to support future IoT applications.)

Design cuts power consumption ‘by up to 50%’

To develop the RM1000, privately-owned Riot Micro assembled a team of engineers – many of them ex-BlackBerry employees – with extensive expertise in Bluetooth, Wi-Fi and LTE design to create an LTE PHY and L2/L3 protocol stack specifically optimised to meet the 3GPP release 13 requirements for Cat-NB1, NB-IoT and Cat-M1 eMTC.

By providing granular control over system resources, the innovative hardware-based architecture minimises active power consumption in all use cases. This design approach significantly reduces silicon area and active power consumption compared to alternative signal processor-based solutions.

“Riot Micro’s innovative approach, leveraging proven design techniques from BLE and
Wi-Fi into the world of LTE, will drive down system cost and power. We want to enable
cellular IoT mass deployment. That will require the cost and energy needs driven to
similar levels as BLE, and our approach gets us there,” says Peter Wong, CEO of Riot
Micro. “We are thrilled with the feedback from lead customers and partners, who’ve confirmed that we offer the only viable NB-IoT platform to enable the price points and
battery life required for mass deployment of IoT applications.”

How to optimise size, power and cost

Riot’s RM1000 is a hardware-centric baseband controller, tightly coupled to an optimized
LTE protocol stack running on an ultra-power efficient integrated processor. The PHY
layer implemented completely in hardware enables minimal eDRX cycle power
consumption and extremely fast wake/sleep transition times. These power savings mean
that IoT modules based on the RM1000 can run longer on lower capacity batteries,
further saving on system cost. Riot’s hardware-based architecture assures that power
consumption is always minimised regardless of traffic patterns and use cases.

Alternative solutions typically require a 100MHz+ processor speed, external memory,
and on-chip PLLs for a high-speed clock, increasing silicon area, power consumption,
and cost. Software-based PHY solutions also have longer startup and shutdown due to
firmware load and processing, which ultimately costs battery life.

IoT Now asks what have been the biggest challenges?

“Test equipment, to be honest. And that still seems to be a bit of a challenge, although it’s getting better. Because of where we were in the development curve for NB1 and MTC, the availability and maturity of test equipment was a real challenge. So we had to work with test equipment vendors’ very early on with some of their beta software. Eventually things matured and it’s getting to a much better point now,” says Wong.

The RM1000 is available now, supplied to OEMs and module manufacturers developing
custom solutions, in an 8mm x 8mm 68 pad QFN package or a 3.5×3.2 mm WLCSP
package. The company offers customer support services, including reference
designs, for evaluation and module design.

Comment on this article below or via Twitter: @IoTNow_OR @jcIoTnow


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