I used a version of it on UK Vodalone company phones in 2005/6. The people who wanted PTT turned it on and nominated up to 3 numbers, then it worked like a normal walkie talkie. Advantage was that blokes pulling cables in on site A could do so without bothering about people working a crane on site B. My phone didn't have a PTT button, so it was voice-operated.
$MEGACORP now uses O2, and no such thing is possible.
PMR radios have rather poor range, and Icom F3000 are expensive. PTT mobiles are a clever idea.
- iPad is an iFAD: Now we know why Apple went running to IBM
- Apple orders huge MOUNTAIN of 80 MILLION 'Air' iPhone 6s
- Climate: 'An excuse for tax hikes', scientists 'don't know what they're talking about'
- Black Hat anti-Tor talk smashed by lawyers' wrecking ball
- +Analysis Microsoft: We're building ONE TRUE WINDOWS to rule us all