Originally Posted by
userasc
I am not sure about the Asia, but last summer I was sailing in Europe ( Adriatics) and I was on a very remote island with only 90 citizens and my internet worked perfectly there.. the signal was great, both on the water and on land.
There is actually possible to find the phone masts maps online in any area.. I will look for this..
In police investigations it is possible to track a mobile phone's path by looking at the change of masts.. so I was thinking if a plane was flying low this could maybe be possible for phones on board..
The normal maximum theoretical range for GSM mobile networks is 35km, except for a few implementations of a special variant used in places like the Australian Outback.
https://en.wikipedia.org/wiki/Timing_advance
More commonly, coverage up to 10-20km from a coast is typical, especially in tourist areas or with lots of maritime traffic, where antennas might be set up specifically for that purpose. There are also special "small cells" occasionally deployed on islands or other remote locations which are miniature cell-towers. Because of the fees from roaming, putting these in locations with lots of tourists can be profitable for the networks.
There is no cellular network coverage - especially 3G/4G Internet capable - in the middle of seas or oceans, except for a handful of cruise ships or oil-rigs with satellite-backhauled small cells.