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Direct-to-Device (D2D) Simply explained

An emergency message sent from an area without mobile network.

A sensor sending data from the middle of the ocean.

A vehicle that stays connected, even outside terrestrial coverage.

All this becomes possible thanks to D2D (Direct-to-Device). In other words: the ability to connect a device (smartphone, sensor, vehicle…) directly to a satellite, without a ground relay.

The principle isn’t new in space. But it’s becoming a standard in telecoms. Why? Because it now integrates with existing mobile networks. Because it uses components compatible with consumer equipment. And above all, because it meets a simple but universal need: staying connected, everywhere, all the time.

What is D2D?

Behind the acronym D2D (Direct-to-Device) lies a simple idea: a device communicates directly with a satellite, without going through a terrestrial antenna. No relay, no ground station. Just the device and the satellite, in direct link.

This link can concern different types of equipment: a smartphone, an IoT sensor, an embedded box in a car… What connects them is their ability to send or receive data without relying on a terrestrial mobile network.

Technically, this isn’t a recent invention. Satellite phones have worked on this principle for a long time. But what’s changing today is the scale. Thanks to major advances in integrating satellite networks with telecom standards (like 5G), D2D is moving from specialized uses to mainstream and industrial applications.

Concretely:

Modems integrated into some recent smartphones can already communicate with satellites (without a dedicated satellite antenna).
Connected objects designed for isolated environments can now do without mobile coverage.
Car manufacturers are considering continuous connectivity for their vehicles, even off-network.

In short, D2D is an already operational technology that is reshaping the communications map.

3 Forms of D2D to Know

When we talk about D2D, we’re actually talking about a common principle, applied to three main types of equipment. Each with its own challenges, uses, and level of maturity.

D2D for smartphone

This is the version getting the most attention right now. Companies like Apple or Google have already integrated D2D functions into their smartphones—without changing design or antenna. Thus, some phones can, in case of emergency, send a short message or share their location even without mobile network.

Today, services are limited (mainly SOS functions), but they’re evolving towards more complete uses, with two-way messaging, and maybe tomorrow voice or data. All this, without specific equipment: these services work directly from a standard smartphone, without needing a phone dedicated to satellite communications.

D2D for automobiles

Here too, the prospects are very concrete. D2D guarantees uninterrupted connectivity, even on journeys outside covered areas. An accident in the mountains? The vehicle can automatically send an alert signal. Car theft? Geolocation remains active, even off-network.

Beyond safety, manufacturers are also interested in connected maintenance: receiving technical data, pushing software updates… without depending on terrestrial network.

D2D for IoT

This is probably the most mature segment today. And it’s also where Kinéis is fully engaged.

The principle is as follows: connected objects (sensors, beacons, mobile equipment…) transmit data directly to the satellite, without going through ground infrastructure.

Here are some very concrete examples:

Container tracking at sea or by rail, as part of multimodal transport.
Pipeline, power line, or water network monitoring in hard-to-access areas.
Environmental data collection (temperature, humidity, air quality…).
Wildfire detection in areas not covered by terrestrial networks.

In all these cases, the logic is the same: ensure uninterrupted connectivity, without depending on cellular coverage.

Understanding D2D at a glance

What D2D Really Changes

D2D does not change connectivity. It changes the rules of the game. Thus, objects, vehicles, and people can stay connected, whatever their environment.
Until now, satellite connectivity was the preserve of a few very specialized sectors, such as defense, aviation, scientific missions, or expeditions… Critical but marginal uses. Today, with D2D, satellite becomes accessible on a large scale, and can be integrated into everyday equipment. And that changes everything!

Concretely:

Coverage becomes global. No more “white zones.” A beacon stays connected in the forest, a sensor sends its data from a remote valley, a container at sea remains visible.

Equipment becomes interoperable. The switch between cellular and satellite networks is automatic, with no human intervention. You no longer “choose” the communication mode: it adapts.

Costs decrease. No need to invest in specific terminals. D2D-compatible components are integrated into standard devices, with much higher production volumes.

Infrastructure is simplified. No need to install relays, deploy a private network, or lay fiber in hard-to-reach areas.
And for industries, this creates new possibilities: deploying reliable, autonomous, and sustainable connected solutions, even in complex environments.

What D2D is not

D2D generates a lot of interest… But sometimes, it causes confusion. So before going further, a point of clarification is needed.

No, D2D does not refer to any communication that passes through a satellite. Just because a sensor sends its data to a ground antenna, which then relays it to a satellite, does not mean it’s D2D.

The heart of D2D is the direct connection between the device and the satellite. No intermediary. No ground gateway. Just the connected object and the satellite. It is this autonomy that changes everything. It is what allows a device to stay connected, everywhere, all the time.

A Concrete Case: Tracking a Container in Multimodal Transport

Let’s take a classic example: a container leaves a warehouse, passes through a port, crosses the ocean, and then travels by rail to its final destination. This container is equipped with a tracking sensor. As long as it’s in a covered area, it uses the cellular network. But as soon as it leaves these infrastructures—out at sea, in rural areas, or on isolated routes—it automatically switches to satellite mode. No data loss, no manual intervention, no disconnection.

This seamless operation relies on a single chip, two antennas, and smart software that manages the transition intelligently. This is exactly what Kinéis offers its logistics customers today: a solution that guarantees complete, uninterrupted visibility, even on complex routes where traditional mobile networks can’t keep up.

How D2D is transforming industries

For businesses, D2D is more than just a technological advancement. It’s an operational accelerator, simplifying connectivity where it was previously partial, expensive, or nonexistent.

In practical terms, it enables:

Continuous monitoring of operations, even in areas without network coverage. No more data gaps or blind spots.
Streamlined infrastructure, with no need for ground-based relays. Connected devices operate autonomously, anywhere.
A unified solution, whether using 4G, 5G, or satellite—same processes, same interfaces, same supervision tools.
Compliance with regulatory requirements, especially for security, traceability, and rapid access to data..
Measurable gains in efficiency, reliability, and responsiveness—across logistics, energy, agriculture, and environmental sectors.

D2D paves the way for a new era: connectivity that adapts to real-world needs, not the other way around.