Satellite & LEO Internet
Satellite & LEO — 5 vendors and operators, each broken down by layer L1 to L7: what they sell at that layer, and which layer is their home turf.
Starlink
Home turf: L1 / L3
L1 Physical
This is this domain's star layer, and its most fundamental difference from every terrestrial carrier domain on this page: there is no last-mile line on the user side — the other end of the link is a satellite at roughly 550 km altitude. That altitude is the starting point for understanding everything else.
L2 Data Link
This layer needs to state its information boundary honestly: this domain's air-interface protocol is proprietary, with no public standards document to cite the way Ethernet or Wi-Fi have, so this site does not speculate about frame formats or modulation details.
L3 Network
This is this domain's second star layer, and the one that most directly shapes how users can actually use the service: by default it assigns addresses behind CGNAT (carrier-grade NAT) rather than public IPv4 addresses.
L4 Transport
This layer has no product this domain sells, but there is one real behavioural difference that must be made clear: latency on this link is not a stable value but continuously variable, with sources including the periodic satellite handovers noted at L2, weather effects on the radio link, and shifting user load within the same beam.
L5 Session
A standard account and device management session — logging in via the official app or web console, binding and managing terminal devices, changing service addresses, and viewing usage and billing — mechanically not fundamentally different from the self-service portals of other carrier domains on this page, and this domain has not built a distinctive capabili…
L6 Presentation
This layer is explicitly empty — no product or service. This domain has no standalone encryption or presentation-layer product; link-level encryption is a built-in capability of its air interface and network infrastructure rather than a separately sold product line, and end-to-end encryption on the user side is the application's own responsibility (HTTPS, fo…
L7 Application
This layer holds two pieces. The first is a conventional service product line and management application: tiered plans for residential, mobility, maritime, aviation and business scenarios, plus the official app — which includes one utility specific to this class of service, checking an installation site's sky obstruction using augmented reality, correspondin…
Eutelsat OneWeb
Home turf: L1 / L7
L1 Physical
This is this domain's star layer, because at this layer it holds a structure currently unique to it: operating a geostationary fleet and a low-orbit constellation at the same time. The Eutelsat side brings mature geostationary resources (roughly 35,786 km, one satellite covering an enormous area, latency around 600 ms, suited to broadcast and non-interactive…
L2 Data Link
As with this page's Starlink domain, this domain's air-interface protocol is proprietary with no public standards document to cite, so this site does not speculate about frame formats or modulation details.
L3 Network
What most needs clarifying at this layer is not a technical mechanism but a real consequence of the business model: this domain is wholesale-only, selling capacity to distributors, telecom operators and ISPs who then face end customers — so how end users' IP addresses are assigned, whether NAT is applied, and whether public addresses are issued are all decid…
L4 Transport
This layer has no product this domain sells, but one order-of-magnitude difference is worth recording: its low-orbit constellation sits at roughly 1,200 km, so geometric round-trip latency is necessarily higher than this page's Starlink domain at roughly 550 km, while a workload riding its geostationary fleet instead faces an entirely different order of magn…
L5 Session
This layer is explicitly empty — no product or service. This is a direct consequence of the wholesale-only model: this domain does not provide service to end users, so no end-user account system, self-service console or device-management session exists.
L6 Presentation
This layer is explicitly empty — no product or service. This domain has no standalone encryption or presentation-layer product; link-level encryption is a built-in capability of its air interface and network infrastructure rather than a separately sold product line.
L7 Application
This is this domain's second star layer, because both of its core stories land here. The first is the wholesale-only distribution model itself: it does not sell to individual consumers, instead selling capacity to distributors, telecom operators, ISPs, and maritime and aviation service providers who handle end service, pricing and customer support.
Amazon Kuiper
Home turf: L1 / L7
L1 Physical
This is one of this domain's star layers. It plans a low-orbit constellation on the scale of thousands of satellites (a published plan of roughly three thousand-plus, with the actual in-orbit count changing continuously, per the latest official disclosure), using Ka-band and equipped with optical inter-satellite links, meaning data can relay directly across…
L2 Data Link
As with this page's Starlink and Eutelsat OneWeb domains, this domain's air-interface protocol is proprietary with no public standards document to cite, so this site does not speculate about frame formats or modulation details.
L3 Network
The conventional part of this layer resembles this page's other satellite domains: data descends via satellite to a ground gateway and enters the terrestrial internet, or relays in orbit via optical inter-satellite links before landing.
L4 Transport
This layer has no product this domain sells, and its behavioural characteristics match this page's other low-orbit domains, so the mechanics are not repeated: low-orbit altitude puts latency in the tens of milliseconds (far better than geostationary orbit's roughly 600 ms), but latency is variable rather than stable, with sources including periodic satellite…
L5 Session
A standard account and device management session — account login, terminal binding and management, usage and billing queries — mechanically not fundamentally different from the self-service portals of other cloud and carrier domains on this page, and this domain has not built a distinctive capability at this layer.
L6 Presentation
This layer is explicitly empty — no product or service. This domain has no standalone encryption or presentation-layer product; link-level encryption is a built-in capability of its air interface and network infrastructure rather than a separately sold product line, and data encryption in enterprise scenarios is typically handled by key-management and encryp…
L7 Application
This is this domain's second star layer and where its real differentiation lies: integration with AWS. The other two satellite domains on this page are positioned to sell connectivity, after which where the data goes is not their concern; this domain's parent company also operates one of the world's largest cloud platforms (this page's AWS domain), so it can…
Viasat
Home turf: L1 / L4 / L6
L1 Physical
This is one of this domain's star layers, and its structure here differs completely from the three satellite domains preceding it on this page: it is geostationary-first, not a low-orbit constellation.
L2 Data Link
This layer has one structural relief compared with the three low-orbit domains on this page: a geostationary satellite is stationary relative to the ground, so there is none of the periodic handover from one satellite to another every few minutes that low orbit requires — the link is stable at this layer, an uncommon advantage of geostationary orbit.
L3 Network
This layer is conventional IP transport: user traffic travels via satellite to a gateway station and joins the terrestrial internet on the gateway side. Similar to this page's Starlink domain, its consumer service typically also places users behind carrier-grade NAT, so port forwarding and inbound-connection usage are likewise constrained, and scenarios need…
L4 Transport
This is the only one of the four satellite domains on this page with a real product at L4, and physics is what forced it. Geostationary orbit's roughly 600 ms round-trip latency is unavoidable, and traditional TCP performance correlates strongly with round-trip time — every window doubling during slow start waits a full round trip, so a 600 ms round trip can…
L5 Session
A standard account and terminal management session — account login, terminal and usage management, billing queries — mechanically not fundamentally different from the self-service portals of other carrier domains on this page.
L6 Presentation
This is a rare non-empty presentation layer on this site and deserves particular note. The L6 layer of the overwhelming majority of domains here is empty, because encryption is usually a built-in capability of underlying infrastructure or the application's own responsibility rather than a separately sold product line.
L7 Application
This layer holds three businesses, one of which is unique on this site. The first is in-flight connectivity (IFC): providing cabin internet for airlines, one of this domain's best-known businesses and one of the most fitting applications for geostationary high-throughput satellites (aircraft cross wide areas and need continuous coverage).
AST SpaceMobile
Home turf: L1 / L2
L1 Physical
This is this domain's star layer, because its entire engineering difficulty concentrates here. Connecting an ordinary phone directly to a satellite hundreds of kilometres away runs into the link budget: a phone transmits at a fraction of a watt with very low antenna gain, and that end's capability cannot be improved (requiring users to change phones would de…
L2 Data Link
This is this domain's second star layer and where it is unique on this site: the air-interface protocols of the other four satellite domains here are all proprietary with no public specification to cite, and this one is not — it uses standard 3GPP cellular protocols (4G/5G).
L3 Network
The mechanics at this layer differ fundamentally from this page's other satellite domains: its traffic does not land at its own gateway before entering the internet but enters the partner mobile operator's core network — because within the whole arrangement its satellite plays the role of a base station on the partner operator's network, and the user's netwo…
L4 Transport
This layer has no product this domain sells. Low-orbit altitude puts latency in the tens of milliseconds, far better than geostationary orbit (roughly 600 ms in this page's Viasat domain), so transport-layer acceleration products such as that domain deploys are unnecessary.
L5 Session
This layer is explicitly empty — no product or service. This is a direct consequence of its business model: it does not face end users directly, and users' accounts, authentication and sessions all sit on the partner mobile operator's side — the user keeps their original phone number and SIM and remains that operator's subscriber on the network side, so no a…
L6 Presentation
This layer is explicitly empty — no product or service. This domain has no standalone encryption or presentation-layer product; the air-interface encryption built into cellular standards is part of 3GPP itself, carried jointly by the standard protocols and the partner operator's core network, and does not constitute a separately sold product line of this dom…
L7 Application
The core of this layer is its business model: reaching users through partner mobile operators rather than building its own retail operation. The reason ties directly to the spectrum constraint at L2 — phones only recognise the cellular bands they support, and those bands are held by mobile operators in each market, so it must partner country by country with…