On Thu, 03 May 2018 09:14:00 +0000, Chris Rowland wrote:

Phones can't communicate with each other, they communicate with the cell
towers.

.... which is why this new GliderLink system is using the goTenna radio
mesh system for its M:M radio link. The phone uses a 1:1 Bluetooth
connection to the Gotenna mesh transceiver, which operates on one of the
unlicensed bands. Like FLARM, the band used varies from country to
country.

This communication is designed to be one to one, not one to
many which is what is required. Also the Cell tower aerials are
designed to communicate with phones at grund level, not phones in the
air. This means that the phone gets unreliable above a few thousand
feet.

.... and even lower in some parts of the UK. I've had no bars at all at
3000 ft in a thermal over the centre of Huntingdon. I can only suppose
that, because the southern English counties can be regarded as optically
flat for RF purposes, the telcos provide as little vertical coverage as
possible to minimise their cell tower electricity bills.


--
Martin | martin at
Gregorie | gregorie dot org