Steve Terry wrote:

Clearly there are two distinct points of view, one that stifled cellular PTT
offers cheap and practical closed group comms for the benefit of all users,
and two those with a vested interest in perpetrating the vast bureaucracy
and £Billion budgets of Tetra that didn't exist ten years ago, and are
looking forward to a replay with even bigger budgets and careers
to be made with the future planned Tetra 2.

GSM can't do the sort of PTT that is required by the emergency services.
I suppose you could design something on top but it wouldn't really be
GSM anymore. One of the fundamental problems is the fact that GSM takes
a while for call set up.

Meanwhile on the streets, emergency services will continue to fall back
on their mobile phones for calls, and Blackberrys for correlating data.

It is true that reactive police typically carry and use GSM handsets and
Blackberrys but that is only one of many different emergency services or
even functions within the police.