2nd link clear said "satellite network, users can send and receive text messages when well out of cell phone signal coverage." That's mean it's use GPS two ways without cell phone needs.
right... it uses Iridium for satellite communication. Its GPS functionality is not two-way. It's only equipped with GPS receiver.
GPS technology is a very very simple concept. you need at least 24 GPS satellites orbiting around the world to get GPS coordinate anywhere in Earth. GPS satellite only sends signal and you can receive that signal with any receiver device. you need at least 4 satellites for a coordinate. the more satellite links your device receives... the more accurate it is. the more accurate it is.... the bigger your receiver is... which means more power is needed. Garmin, TomTom, etc. compete with each other over better receiver technology and basemaps. They do not own GPS satellites. Only government owns and controls satellites and very few companies can build GPS satellites for government like Boeing.
Chinese, Russian, Indian, American, etc. have their own GPS satellites. why? simple.... for their precision-guided weapons. The government can turn off GPS access for civilians at ANYTIME. that means.... all devices using GPS such as Garmin, TomTom, Google Map, etc. will be rendered useless if the government cuts off the access.
why is this simple concept very hard for you to grasp? stop being stubborn.
First you said ALL GPS technologies are the same. all GPS technologies are one-way communication now you said 2-ways GPS. Get a fact next time.
I think you don't really understand what I'm saying.
and GPS devices means ALL GPS technologies are the same. all GPS technologies are one-way communication (except GPS satellites and operation centers) and all GPS technology function the same - triangulating with at least 4 satellites.
use your common sense. obviously - we're talking about GPS technologies that anybody can use and that technology is one-way only.
Because you never seen commercial GPS before and you just guess that it use cell phone. Really?
lol...... lol...... lol..... I know how it works and what it does and trust me.... it does not use GPS for 2-ways communication. For 2-ways... it uses either or both radio, cell, and satellite (ie - Iridium). Commercial GPS only receives.... not sends.
FYI - Iridium is NOT a GPS satellite. It's a 2-way satellite communication....
I don't think you understand what 2-ways GPS satellite means. GPS satellite's primary function is to SEND coordinate signal to a receiver and that's it! Nobody except government can send signal to GPS satellite. The only reason for government to send signal to GPS satellite to is to update the software or to reposition it.
Do you know what makes it a "Commercial GPS"? It's for a company to monitor and keep track of their trucks as well as to control their trucks (2-ways via cell/radio/satellite and no not GPS satellite... Iridium Satellite or other 2-ways communication satellite). Can you do that with your regular Garmin or TomTom GPS? there you go.