Satellite is moving into the cellular roadmap: An emerging layer for critical IoT

Direct-to-Device satellite (D2D) services have moved from trial to early commercial deployment in the UK and US over the last twelve months, while Europe progresses through D2D-MES (Mobile Earth Stations) launches, CEPT (European Conference of Postal and Telecommunications Administrations) harmonisation work and post-2027 MSS (Mobile Satellite Service) spectrum decisions.

In our recent piece on the Ofcom Spring 2026 Connected Nations update, we noted that satellite is becoming a serious resilience layer for critical connectivity, and that direct-to-cell services (sometimes called D2D) were being piloted by some mobile operators. Since then, the picture has accelerated quickly.

This post is a precursor to a fuller series:

A white paper and an executive digest will follow, covering where D2D fits today, where it does not yet, and what that means for critical IoT connectivity architecture.

Key developments that have moved D2D from regulatory consultation into commercial service include:

• In February 2026, Ofcom finalised the UK D2D Exemption Regulations (Wireless Telegraphy (Direct to Device Satellite Communications) (Exemption) Regulations 2026, S.I. 2026/139, made on 16 February 2026). Ofcom approved the first Mobile Network Operator (MNO) licence variation for Telefónica UK / VMO2 at 1800 MHz, and the associated device exemption has been in force since 25 February 2026.
• On 26 February 2026, O2 Satellite went commercial over the new framework, using Starlink Direct to Cell. It is the first commercial D2D service launched under the UK Ofcom framework, and one of Europe’s first commercial mobile-spectrum D2D services. The service launched on selected Samsung devices with messaging and app/data capability, rather than SMS alone.
• In April 2026, the FCC (US Federal Communications Commission) granted AST SpaceMobile authority (DA-26-391, 21 April 2026) over a 248-satellite constellation in collaboration with AT&T, Verizon and FirstNet, the second major US D2D development after T-Mobile and Starlink’s T-Satellite service, commercially available in the US since July 2025. Ofcom also approved a second UK variation for VodafoneThree at 900 MHz, with the corresponding exemption-regulations amendment consultation closed on 18 May 2026; the final amendment is not yet confirmed as made at the time of writing. First customer trials are planned for Summer 2026 via Satellite Connect Europe.
• The European Commission issued a CEPT mandate in October 2025 to develop harmonised technical conditions for D2D in EU mobile bands, with deliverables running through 2028. Produced by the Electronic Communications Committee’s ECC Report 373, and approved 13 February 2026, sets out the regulatory and technical considerations for satellite D2D in MSS and MFCN (Mobile/Fixed Communications Networks) frequency bands.
• 3GPP standards have moved alongside. Release 17 introduced satellite into the cellular standard (NR NTN [5G New Radio interface for satellite] and IoT NTN). Release 18 added optimisation. Release 19, frozen in December 2025, continued NTN evolution, including IoT NTN enhancements and store-and-forward operation. Release 20 will continue the work, including around NTN voice, but is still in progress.
• Globally, the GSA (Global Mobile Suppliers Association) reports 275 publicly announced operator-satellite NTN partnerships in 101 countries and territories as of April 2026, with 57 operators in 35 countries running commercial offerings and 21 satellite-to-cellphone services live in 17 countries.

It is worth being precise about which satellite is which. The lower-cost Starlink home plan that Ofcom counted as making decent broadband affordable in the Connected Nations Spring 2026 data is a dish-to-home service: a satellite dish installed at the property. The services this post is about, and that the upcoming pack covers in depth, are direct-to-device: standard handsets and SIM-enabled devices connecting straight to a satellite, without intermediate terminal hardware. Both are satellite, but they sit in different layers of the resilience architecture.

For a connectivity decision-maker, the headline is straightforward: satellite is becoming an integrated layer in the cellular roadmap.

If you are responsible for critical IoT connectivity, three points are worth carrying forward into procurement and architecture conversations.

First, “satellite” is now four different things. The European Commission’s spectrum policy group, RSPG (Radio Spectrum Policy Group), distinguishes at least four service categories: D2D in mobile (IMT-International Mobile Telecommunications) spectrum, MNO-led under Ofcom or FCC; D2D in mobile-satellite service (MSS) spectrum, satellite-operator-led, which includes today’s smartphone satellite-SOS and satellite messaging services; satellite-operator-spectrum IoT NTN via 3GPP NB-IoT (Narrowband IoT) or eMTC (enhanced Machine-Type Communications), the enterprise IoT case (this is the buyer-facing shorthand for what RSPG describes through several adjacent categories); and D2D in short-range device bands, still niche today. Each comes with a different regulator, different operators, different SIM and contract entitlements, and a different commercial fit. Which category a service falls under matters before any procurement conversation begins.

Second, the access layer alone is not a resilience strategy. This is the same point made in our Connected Nations Spring 2026 piece: coverage is not resilience. Ofcom’s own Spring 2026 data made the same case at the terrestrial layer. Predicted indoor 4G coverage of UK premises is 99.7% from at least one MNO, but only 91% from all four. In rural areas the gap widens to 98% versus 64%, a 34-point difference. The same logic applies above the cellular layer. Adding a satellite path to a critical IoT estate adds reach, but with two practical limits. The reach is mostly outdoor: today’s device-level D2D and IoT NTN services depend on unobstructed view of the sky visibility and remain limited indoors, where many critical IoT devices (alarm panels, telecare units, building monitoring) actually sit. Also, reach is not continuity: a single-MNO D2D service routed through one operator’s core, however good its satellite coverage, is still single-MNO at the layer that matters most for resilience. Critical IoT continuity comes from how access paths, SIM-layer switching and the control and assurance layer above them interact.

Third, the regulatory picture differs by jurisdiction. The UK, the US and the EU are all moving on D2D, but their legal frameworks are not identical. Ofcom’s model is a wireless telegraphy licence variation plus exemption regulations. The FCC’s Supplemental Coverage from Space framework is based on US spectrum allocations, leasing arrangements and Part 25 satellite authorisation. The EU is still at the harmonisation and feasibility stage for D2D in EU-harmonised mobile bands. A multi-country IoT estate will encounter three sets of regulatory conditions, three sets of obligations and three timelines.

For most CSL customers, the immediate question is not whether NTN and D2D change the picture in five years; it is what, if anything, they should do this year. No urgent action is required. The resilient architecture already in place is the right foundation, and satellite can be added to it deliberately, where it earns its place.

CSL’s approach to resilience is built across layers: radio access, network choice, core-network independence, backhaul diversity, device behaviour and managed visibility. Satellite is becoming a more visible layer in that stack, not a replacement for any of the others. Track 1 D2D over mobile spectrum (for SIM-enabled devices on supported operator networks), Track 2 IoT NTN over MSS spectrum (for NB-IoT modules), and LEO satellite (Low Earth Orbit) as a managed site-level layer (already part of CSL Satellite) each have a place in the architecture. The work is integrating whichever ones are commercially and technically right for a given estate.

For estates already running on multi-network SIMs, rSIM® dual-core resilience or CSL’s router and CSL Satellite combinations, that integration is something CSL helps design in. The specific path depends on the use case. Track 1 D2D works through a supporting MNO’s network and requires D2D-capable devices and the right MNO contract. Track 2 IoT NTN needs NTN-capable modules and satellite-operator SIMs, typically deployed at the next hardware refresh. LEO at the site uses a terminal, already part of CSL Satellite. Existing investments are not made obsolete because new spectrum bands enter commercial service; they become the resilient baseline that satellite layers are added to, in the same way the gradual arrival of 5G SA (5G Standalone) or LEO broadband strengthens rather than undermines a well-layered estate. As we noted in our Connected Nations Spring 2026 piece, resilient architectures are designed to absorb network change at the right refresh point.

For CSL customers, the practical takeaway is straightforward: satellite is a planning conversation worth having early, not a procurement decision worth rushing. CSL is well placed to have that conversation alongside the architecture already in place, and the pack to follow gives the framework.

This post is the first piece in a short series. The pack to follow will include:

• A white paper covering the regulatory map across the UK, US and EU, the four service categories, the three-layer resilience architecture, the rSIM® case for SIM-layer resilience, three customer pathways and a decision guide.
• An executive digest of the central argument and frameworks, designed for mobile reading.

If you are designing connectivity for a critical IoT estate that operates across borders, or one that depends on uninterrupted access for safety-critical applications, the full pack is the place to start. We will share each piece as it goes live, and welcome the conversation in the meantime.

• What Ofcom’s Spring 2026 Connected Nations Update Means for Critical Connectivity, 22 May 2026. Where terrestrial coverage stands, and why coverage alone is not resilience.
• EU Cyber Resilience Act for IoT: Why Resilient Connectivity Matters. Why lifecycle security, updateability and incident response depend on being able to reach connected devices in the field.
• CSL Satellite. LEO satellite connectivity integrated with intelligent router failover, for site-level resilience.
• rSIM®. Dual-core resilient SIM for autonomous switching across networks.

• Ofcom, Connected Nations update: Spring 2026, published 13 May 2026.
• Ofcom, Statement: Enabling satellite Direct to Device services in mobile spectrum bands (final regulations, 17 February 2026; regulations in force 25 February 2026); Wireless Telegraphy (Direct to Device Satellite Communications) (Exemption) Regulations 2026, S.I. 2026/139.
• Ofcom, Consultation: D2D licence exemption regulations update (VodafoneThree 900 MHz amendment, consultation closed 18 May 2026; final amendment not yet confirmed as made).
• Virgin Media O2, O2 Satellite launch announcement, 26 February 2026.
• T-Mobile, T-Satellite with Starlink commercial launch, July 2025.
• FCC, FCC Authorizes AST to Provide Supplemental Coverage from Space (DA-26-391), 21 April 2026.
• CEPT, ECC Report 373: Satellite-based D2D communications, approved 13 February 2026.
• 3GPP, Non-Terrestrial Networks (NTN) overview.
• GSA, NTN Connectivity Report, May 2026 edition (April 2026 figures).

This is the first post in CSL Group’s Resilient Connectivity Series on NTN satellite and Direct-to-Device connectivity in critical IoT. To talk through how D2D fits in your existing connectivity architecture, contact CSL.