Satellite Is the Flavor of the Month for the Cellular IoT Industry

At Mobile World Congress (MWC) 2023, the satellite was one of the most popularly discussed topics among major semiconductor manufacturers, device Original Equipment Manufacturers (OEMs), network infrastructure manufacturers, and wireless carriers. 3GPP has been discussing the union of terrestrial and space-based communications since the 3G standards. 3G, aka UMTS Terrestrial Radio Access (UTRA), was the Earth-bound portion of the conceptually grander Universal Mobile Telephone System (UMTS). And although the Global Standard for Mobile (GSM) put a hard stop on satellite phones becoming a mass market standard for portable personal telephony in the 1990s, cellular and satellite were never truly competitors. Their complementarity in geographic coverage and as fallback and/or backhaul for one another has been acknowledged for decades. The problem was always that the cost of integration was prohibitive, due to cellular and satellite being just too different in the way that they worked—until 3GPP Release 17 in mid-2022, and the formal recognition of satellites as part of Non-Terrestrial Networks (NTNs) for 5G.

Stalwarts of the cellular industry have been quick to develop support for satellites, almost surprisingly so, in their quest for differentiation, bragging rights, and to become the de facto technology partner for others to fall in line with. The weak signals transmissible between ground mobile devices and satellite constellations are of limited, but potentially life-saving, use in the consumer domain, allowing emergency text messages to be sent and received. But this same ability is of far greater and more regular utility in the enterprise Internet of Things (IoT) domain, and short messages may be all that is ever needed to constitute the basis of a mission-critical managed service. MWC 2023 confirmed that combined cellular-satellite IoT services will be offered by major international carrier groups starting in 2H 2023.

This will be to serve outdoor use cases to address existing customers in need of full coverage, which is a big issue for stationary IoT devices. It will also be for the sake of onboarding new IoT customers, as some enterprises will not commit to any service provider without the guarantee of 100% continuity of global service availability. Satellites will be used to extend carriers’ Narrowband IoT (NB-IoT) footprints, which is especially compelling for those customers not currently interested in NB-IoT, due to its fragmented roaming and feature support. Plus, satellites will solve service fragmentation, so that enterprises need just one service provider for all IoT connectivity needs. Additionally, it aims to solve device fragmentation, so that a single piece of hardware is all that is needed to connect to both networks.

Foundational namesake features of cellular Low-Power Wide Area (LPWA) technology, notably the power-saving ability of Extended Discontinuous Reception (eDRX), cannot be supported by IoT device OEMs, because eDRX cannot be guaranteed to be available while roaming, due to carriers around the world being inconsistent in the LPWA features they have chosen to implement. This means that today’s IoT device OEMs are forced to select the lowest common denominator LPWA features sets for their equipment. Just as they have chosen to make use of the venerable 2G for so many years, and are currently making such extensive and increasing use of Cat.1 Long Term Evolution (LTE). OEMs must only choose what is ubiquitously available to uphold the promises of continuity of service availability they make to their own customers—guarantees their customers need in order to purchase from them in the first place.

Remarkably, NTN is a software feature, and does not exist in the transistors of the silicon of the cellular baseband chipset per se. One of the first commercial implementations of NTN was announced at MWC in 2023. The motorola defy satellite link Bluetooth peripheral is the “puck” that ruggedized handset manufacturer Bullitt Group is using for its Bullitt Satellite Messenger service. The motorola defy contains MediaTek’s Dimensity NTN-capable chip, with Bullitt Satellite Messenger service making use of Low Earth Orbit (LEO) satellite constellation operator Skylo and integrated Subscriber Identity Module (iSIM) provider Kigen to combine satellite and cellular connectivity. Motorola and Bullitt launched three devices in total, the aforementioned defy peripheral for legacy handsets, the motorola defy 2 smartphone that integrates the Dimensity NTN functionality directly, and Bullitt’s own Cat S75 phone.

NTN is a force for collaboration, bringing together five distinct telecommunications specialist companies in this strategic partnership. With Bullitt’s Satellite Messenger service not just being for SOS applications, but for two-way messaging. IoT applications will follow soon. Cellular LPWA semiconductor manufacturer Sony Altair announced that its recent ALT1350 LTE-M/NB-IoT chipset was designed with specific support for NTN, and that its existing ALT1250 chipset can be upgraded through firmware to support NTN. However, ALT1250 chips that have already been deployed in IoT devices are unlikely to be upgradable, as slightly different antennas are also required for NTN. Asset tracking and stolen vehicle recovery are being mentioned as early IoT applications for the technology.

Satellite has always been important for filling connectivity gaps, especially for smaller specialist IoT service providers, and dedicated IoT Mobile Virtual Network Operators (MVNOs). This was a market pioneered by ORBCOMM and Numerex (now owned by Sierra Wireless/Semtech). But mainstream cellular carriers are now racing to work more closely than ever with satellite operators, with key partnerships known to be in place with Sateliot, Intelsat, and Skylo. IoT carriers are likely to need multiple satellite partners for redundancy, coverage, and capacity, prioritized through synergies between their respective API offerings, for use by IoT application developers. It is hoped that satellite will not be a niche offering for IoT carriers, but will be mainstream. Even if it is only for fallback, why would an enterprise not opt for it just in case? An extreme result may even be that satellite-only customers disappear, as a natively converged cellular-satellite service means they can use cellular as a cheaper option when possible, only reverting to satellite when necessary.