This (German) and this is some new network which has antennae pointing upwards.
It is a joint venture with Inmarsat whose network would be used when the aircraft is too high.
It appears likely that this is not going to be available for roaming on terrestrial contract phones. Does anyone know anything about it?
Existing 4G (and to a much lesser extent 3G) does work when airborne but above some 2000ft it is highly sporadic. All of Belgium has zero coverage (for my Vodafone UK phone) and on say a 5hr flight one might get a few seconds of connectivity once an hour. It has been sufficient for getting tafs/metars though and I have used my Thuraya satphone much less as a result.
Peter wrote:
but above some 2000ft it is highly sporadic.
I have no experience in Belgium but I recall even making a VOIP call at about FL100 in france, and there being consistently better network there than the UK, where it also dies as soon as you get higher than the control tower!
Here is a good thread on that topic, but AFAICT this new project won’t roam with existing phones, or at least not with existing terrestrial contracts.
If it worked with existing phones, how will it hand over to Inmarsat? Only by having a “femtocell” in the aircraft. Or maybe a WIFI AP, but that would need the phone to run VOIP. But that suggests dedicated hardware in the aircraft would probably be required even if the ground towers are being used.
Does anyone know anything about it?
On the Inmarsat website they say " Aviation terminals – Aircraft will be equipped with terminals for both the S-band satellite and the high-speed broadband ground network, to enable seamless connectivity across the entire coverage region. " As I understand it, the end user phones will not connect directly with those upward facing LTE cells. Hopefully at least… as if flying as passenger is not bad enough already, soon one will be forced to listen to the conversations of a dozen people sitting around oneself, none of which is more than one metre away.
Around Milano I regularly get connection for more than just a few seconds at FL160 
what_next wrote:
as if flying as passenger is not bad enough already, soon one will be forced to listen to the conversations of a dozen people sitting around oneself, none of which is more than one metre away.
Cabin door will be badly needed
I regularly have 3G at FL110-120 when flying overhead Bosnia, sometimes during all flight (usually 30-45 min).
These posts are off topic 
This does not appear to be a product accessible with a phone.
Of course there is GSM coverage in places, especially in mountainous areas. FL160 in the Alps, no problem.
Is GSM even useful any more? It seems neglected by the operators, I’m in an area right now where GSM is the only thing available. Even when the phone reports a solid signal and GSM available, you can’t pass a single byte through it, forget establishing a tcp connection…
I was using “GSM” generically. You should get GPRS over it, say 20kbits/sec. If there is no GPRS you can usually do the 9.6k dial-up GSM is still used for voice and SMS although I think some of it goes via 3G/4G if available.
I am amazed that this new venture can make money, after installing all that extra hardware, just selling bandwidth to airliners. Didn’t Boeing close down a similar venture recently (implemented over a satcomms link)?
