eli5 how come airplanes have wi-fi but we can’t get a phone signal?
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Phone signal connects to the nearest cellular tower. WiFi is max 150’. The airplane does come with phones, but they don’t use the terrestrial cellular network; they use satellites. Some airlines stick a cellular converter onboard so it becomes the local cell tower that then connects to satellite; this is tricky though due to cellular bands having some overlap with avionics equipment in some countries.
A cell signal is too weak at that altitude to make a decent connection, especially when cell towers tend to broadcast outward and not upward. The internet that planes get is through satellite signals.
Phone signal connects to the nearest cellular tower. WiFi is max 150’. The airplane does come with phones, but they don’t use the terrestrial cellular network; they use satellites. Some airlines stick a cellular converter onboard so it becomes the local cell tower that then connects to satellite; this is tricky though due to cellular bands having some overlap with avionics equipment in some countries.
There’s no point in operating a femtocell or similar solution when WiFi is already provided.
The internet connection on board is provided by equipment on the plane itself, using a backhaul of either satellite communications or antennas to ground cell towers.
Meanwhile your phone is trying to reach ground cell towers from miles in the air: that’s not going to work.
A cell signal is too weak at that altitude to make a decent connection, especially when cell towers tend to broadcast outward and not upward. The internet that planes get is through satellite signals.
There’s no point in operating a femtocell or similar solution when WiFi is already provided.
The internet connection on board is provided by equipment on the plane itself, using a backhaul of either satellite communications or antennas to ground cell towers.
Meanwhile your phone is trying to reach ground cell towers from miles in the air: that’s not going to work.
Phone signal connects to the nearest cellular tower. WiFi is max 150’. The airplane does come with phones, but they don’t use the terrestrial cellular network; they use satellites. Some airlines stick a cellular converter onboard so it becomes the local cell tower that then connects to satellite; this is tricky though due to cellular bands having some overlap with avionics equipment in some countries.
A cell signal is too weak at that altitude to make a decent connection, especially when cell towers tend to broadcast outward and not upward. The internet that planes get is through satellite signals.
There’s no point in operating a femtocell or similar solution when WiFi is already provided.
The internet connection on board is provided by equipment on the plane itself, using a backhaul of either satellite communications or antennas to ground cell towers.
Meanwhile your phone is trying to reach ground cell towers from miles in the air: that’s not going to work.
WiFi and Cellular are completely different radios. They have different specifications and operate in different frequency spectra.
Your phone generally will not work on a plane for a number of reasons, one of which is that they tend to restrict transmission in the vertical direction since this would be a waste of power. You’re also moving very quickly and passing from one cell to another very quickly. You’re also in a bit of a Faraday cage (surrounded by the aluminum fuselage).
When you connect to WiFi on a plane you are connecting to the planes local WiFi network. These generally have a single satellite connection through a roof mounted antenna. While you could technically make VoIP calls through this, it is against every major carrier’s policy (in the US at least).
Satellite phones should in theory work, but you are still in a Faraday cage, and unlikely to have a usable signal without an external antenna.
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