A Summer of Satellite for the IoT

It was a summer of satellite developments for the Internet of Things (IoT), as big cellular integration projects were announced by two renowned Narrowband IoT (NB-IoT) chipset manufacturers on the same day. On August 19, 2020, Sony Semiconductor Israel declared that it was working with startup Skylo Technologies to develop and deploy NB-IoT-based chipsets that use a gateway to connect to satellites in Geostationary Orbit (GEO) to realize a global network of “NB-IoT over satellite” connectivity. With identical timing, MediaTek stated it had successfully completed a field trial with long-standing satellite incumbent Inmarsat to achieve bi-directional communication between a terrestrial satellite-enabled NB-IoT device and Inmarsat’s Alphasat L-band satellite. NB-IoT is definitionally a “wide-area” technology, and the use of satellite to backhaul its signals over 35,000 kilometers into space—and back again—genuinely takes the concept to the next level!

Sony Semiconductor Israel was born out of the US$212 million acquisition of Altair Semiconductor by Sony Corporation in 2016, approximately 10 years after Altair was founded by ex-Texas Instruments (TI) employees. Rebranded as Sony Semiconductor Israel in July 2020, Altair has become Sony Corporation’s dedicated IoT semiconductor division. Sony benefits from the acquisition of Altair’s mature IoT chipset product line, which represents years of dedicated development, while Altair acquires the backing and financial security of one of the world’s largest electronics manufacturers. Its Skylo partnership is the first major engagement for Sony Semiconductor Israel since being renamed; Skylo itself was only formally announced in January 2020, after acquiring US$103 million in capital investment led by Softbank having raised US$116 million in total since its founding in 2017.

MediaTek and Inmarsat need little introduction: the former is the world’s fourth largest fabless semiconductor manufacturer, while the latter operates a constellation of 13 communication satellites and has been run as a private service provider since 1999. Altair and MediaTek have been NB-IoT competitors since late 2017/early 2018. MediaTek currently sells its single-mode MT2625 NB-IoT chip and NB-IoT+2G MT2621 chip, while Altair offers its dual-mode NB-IoT and Cat.M ALT1250 chip. Skylo, meanwhile, is a new entrant and proponent of Satellite NB-IoT, offering the Skylo Hub, Skylo Data Platform, and Skylo Network. Skylo Hub is as a self-installable satellite terminal and hotspot for Bluetooth, Wi-Fi, and cellular devices, incorporating GPS and an accelerometer, its innovation being Skylo’s “digitally-steered antenna technology,” while the Skylo Data Platform lets enterprises manage their Hubs and the Skylo Network is effectively leased capacity on existing geostationary satellites.

Both initiatives are seeking to influence the 3rd Generation Partnership Project’s (3GPP’s) Release 17 standards, which are due for publication at the end of 2021. Historically, the terrestrial and space-based portions of the 3GPP’s Universal Mobile Telecommunications System (UMTS) were developed separately, coexisting but not compatible. Consequently, the extent to which each was able to complement the other has been strictly limited, necessitating bespoke, hybrid devices to bridge the technology divide. However, the overarching goal of 5G is to unite the increasingly fragmented world of mobile communication under a single standard: cellular networks have shifted to ever-higher frequency bands, spread across ever-more disparate spectrum blocks, in their evolution from 2G to 3G to 4G and beyond. While satellite communication has its own frequency bands to avoid interference, spanning all the way from 1GHz (L-band) to 40 GHz (Ka-band).

The actual market need for seamless global coverage and ubiquitous service availability for IoT connectivity and Low-Power Wide Area (LPWA) technologies is the second driver behind both Sony and Skylo and MediaTek and Inmarsat seeking to combine cellular with satellite. Skylo’s Vice President of Engineering, Moshe Noah, says its collaboration with Sony Semiconductor Israel “provides an entirely new method of connectivity for IoT customers around the world,” while Vice President of Product Management and Marketing at Sony Semiconductor, Israel Dima Feldman, states, “Skylo has extended our chip functionality over satellites to expand the connectivity reach to the most remote locations”. All four parties believe there is a presently unserved opportunity to connect billions of sensor-based IoT devices that could otherwise never be if we try to rely on terrestrial networks alone.

Lastly, there is the ever-present IoT bugbear of cost. Combining the cost-effectiveness and massive scalability of NB-IoT with the strategic deployment of intermediary satellite gateways gives the best of both worlds: global service at minimal cost, at least in theory. Jonathon Beavon, Senior Director for Inmarsat Product Group, asserts that its field tests with MediaTek’s standard NB-IoT chips prove that “technology from mobile networks works effectively over GEO satellites with little modification and will provide a very cost effective path.” In competitor Skylo’s estimation, the cost of NB-IoT over satellite is 95% lower than the cost of using traditional satellite connectivity for the IoT. Both demonstrations showcase the utility of GEO satellite constellations, with no need to deploy new Low Earth Orbit (LEO) satellite clusters thanks to NB-IoT’s low data rate placing minimal strain on the existing GEO infrastructure.

Under 5G, space-based mobile communications are referred to as Non-Terrestrial Networks (NTNs). Ownership of Intellectual Property (IP) that successfully becomes part of each next-generational mobile communications standard is hotly contested, and in 5G the emphasis to date has been on the development of new terrestrial cellular networking techniques. Little attention has been paid to the non-terrestrial portion of the standard, which now emerges as one of the few remaining niches where companies can still contribute to 5G, and thereby secure the rights to valuable long-term royalties, and the opportunity (once enshrined in standards) to sell more NB-IoT and satellite transceiver-based hardware alongside more satellite service subscriptions. The companies that own the IP have the option of passively collecting royalties or actively positioning themselves as the best vendors to buy hardware and services from.

Promoting the use of NB-IoT where cellular networks cannot reach may help NB-IoT break out of the Chinese market and succeed globally, no longer held back by network rollout or roaming issues. It may also help NB-IoT emerge from the shadow of 2G and Cat.1, the stubborn persistence and low cost of the former and the decent future-proofing and international support for the latter being considered “good enough” for enterprises to hold off on the adoption of NB-IoT (and Cat.M) for the time being. Opening up NB-IoT to genuinely new markets untapped and unchallenged by other cellular standards allows it to generate a unique, parallel connectivity business. NB-IoT is the perfect partner for GEO constellations, which are too expensive to routinely augment the capacity of, allowing satellite, too, to break out into massive connectivity. Global GEO constellations are already in place and are ready and waiting to receive NB-IoT-originated data streams.

Unifying cellular and satellite, conceptually within standards and practically in the real-world, has been earnestly sought but never truly approached. That may now change. 5G receives a lot of criticism for appearing ill-defined, or as a technology without an application, or as an example of progress for progress’ sake, but its strength may be as a framework to finally realize the promise of seamless global mobile communications originally promised by UMTS back in 1999. Sony (Altair), Skylo, MediaTek, and Inmarsat are smart to seek to influence Release 17 in an area that is often ignored, to establish an influential foothold in of one of the few remaining telecommunications niches as the IoT continues to be a source of inspiration for innovation, bringing together the unlikeliest of bedfellows in NB-IoT and satellite.