Most pilots have heard of Iridium and Thuraya satphones for getting weather while flying.
Many years ago there was talk of terrestrial cellphones using satellites, not the ground based towers.
Why has none of this moved forward?
Thuraya is still offering their crappy unreliable service, but is an order of magnitude cheaper than Iridium which has a bandwidth useless for most modern applications.
Is it because the network bandwidth required (for cellular comms) is so massive; too great for the ground station to satellite link? Or is it the signal to noise ratio which cannot be achieved over the distance, while keeping the phone stylish and compact? Geostationary satellites have too much latency for voice comms…
@tomjnx used to know a lot about this stuff but he stopped posting a long time ago. Another one was @byteworks, IIRC.
Why has satellite phone technology stalled?
Mainly because GSM roaming was invented. Most of the population is now able to communicate 24/7 wherever they usually go using terrestrial networks. If available those are cheaper to operate and provide more bandwidth, better coverage in buildings etc.
But I see a new potential for satellite based Internet. Some US companies like Facebook seem to work on such projects and I think the politicians over here and in many other parts of the world did not realize yet what this means. So far such companies have to accept some local legislation to avoid beeing blocked but if their signal would come from space I am not sure they would even pick up the phone if some foreign politician would call in Palo Alto…
If such developments will be usable for GA will depend mainly on the antenna requirements. Unfortunately most projects seem to favour more bandwidth with bigger complex antennas which is kind of bad for GA where we need a small and simple omnidirectional antenna like Iridium uses it today.
I wondered if a satellite based terrestrial phone system is even feasible, for the reasons I posted.
It is too late now because the terrestrial networks are established, but an astronomical amount of money has gone into building these, especially as the equipment is mostly not shared between multiple networks serving a given area.
At least some companies are still spending amounts of money on this, just a few weeks the next load of 10 satellites for Iridium NEXT was launched by SpaceX.
The landing and satellite deploy are interesting to watch too.
When I lived in the US in the early 2000, people living in areas where ADSL or fiber was not available used satellite-based internet connections. I never looked into exactly how it worked, or how well it worked… Given the geography I suppose that there is a part of the population for which satellite is the only solution.
Satellite internet was used here too, 15-20 years ago.
Back then I was the local village coordinator (!) for ADSL adoption. It was a scheme which British Telecom ran to ensure ADSL was adopted as slowly as possible so they could make the most money out of 64k ISDN and 9.6k dial-up internet for as long as possible, while charging £11,000/year for 2mbit DSL to see how much interest there was in ADSL among the great unwashed.
There were basically two satellite systems available: bidirectional, and satlink for the downlink with the up data going via a phone line. Expensive, £100/month plus, for Thuraya type speeds. They died out when ADSL came in. Also they got killed by some people getting DSL and re-selling it via WIFI to the neighbourhood. A local pub, a part of a big chain, was doing this on the side, but the owners found out and kicked the manager out.
Will the new Iridium sats provide faster data? Currently the general data service, over which you “can get internet”, is 2400 bits/sec!
Iridium NEXT are targeting up to 1.4MBit/s with their new system, requiring 66 operational and 9 spare satellites.
There is only a very small niche for satellite communication these days and it seems that Iridium is going to address that. The original Iridium was a financial desaster for the investors.
Thuraya is probably not going to make it. It was originally designed for Arabs going places and having a phone but now there is GSM virtually everywhere.
achimha wrote:
Thuraya is probably not going to make it.
Ugh… I hope not. Used my 2nd hand Thuraya phone a couple of time in the mountains last week… works fine even if it looks like something from the distant past.
achimha wrote:
there is GSM virtually everywhere.
“Virtually everywhere” is a huge exaggeration. Look up mobile coverage in countries like Saudi Arabia, and you’ll see only a few percent of the country covered.
And who is in the parts of the country that are not covered?
When the consumer sat phone business plans were made, there was the assumption that settlements need to have a size x for GSM to be viable. Sadly for them, that number x has come down to a very small number. Nowadys even every offshore tourist boat has its own GSM cells.
