KatrinV:Have you mapped coverage in the areas where you work? Has anyone in any reliable fashion
Yes, but unfortunately not to any extent that IMO would be useful to you...
Many of our facilities have no mobile coverage at all... others have part coverage, and while this is mapped in our internal emergency response plans it's only mapped within our property boundaries. Our mapping can embrace several thousand hectares on each site (or even hundreds of sq kilometers on our larger facilities), but it's still only a tiny % of the surrounding unmapped area.
I agree this is an issue - A decade ago we did have accurate maps for entire districts in different countries developed in conjunction with local Emergency Services... Unfortunately this wasn't able to be sustained as we have seen Analogue mobile telephony migrate to CDMA (coverage dropped by an estimated 60% in some places), and again when CDMA was migrated to 3G (coverage dropped again by an estimated further 40% in some places and has not recovered as deployment budgets are cut in this time of financial difficulty).
Add to this...
Our vehicle fleet is provided with external high-gain mobile phone aerials for reason of helping driver emergency communications in the event of accident or break-down - however newer PDA's (iPhone, iMate Ultimate, Palm Treo etc.) do not have car-kits available meaning they cannot connect to external aerials; they only support Blue-tooth -Yet many of our staff like to use these devices (I'm guilty; I have an iMate Ultimate).
An outcome of our adoption of PDA's is that effective mobile coverage has reduced by a further 50% in some areas for people traveling between our sites simply because they cannot use the cars aerial - What's happening in practice is that some people are carrying two mobile phones. One a PDA; one a Nokia or similar to connect in the car.
It's all getting a little ridiculous and is one reason we are now installing dedicated DECT phone systems in some of our larger facilities. It's at the point where we are seriously considering dropping the use of Telco provided mobile phones altogether in some places.