I was about 10 miles out on Lake Erie boating on the weekend. I could not get any cell service on my Blackberry but was none the less able to freely PIN my wife's blackberry back home (which turns out to be an even better arrangement). Does anyone have an explanation as to why one system would work so well and another so poorly? Aren't the digital transmission principals the same?
If anyone calls me when I'm in our data center (which apparently is shielded), my 7100t will never ring, but if they leave a voicemail, I'll get the notification.
I think data is just a little more resiliant (sp?) than voice. Maybe for data, the BB just sits there trying and trying and trying and trying until it gets just enough signal to get/send a message, whereas a voice phone call gives up easier?
I know when I'm REALLY in a no-signal area (vs. a really low signal area) that I don't get ANYTHING .. data or voice.
A voice call requires a certain amount of bandwidth (around 16kb/s for "ok" quality). If you're in a very weak signal area, you might not have a strong enough signal to maintain this transfer rate, and thus a voice call will not go through, or will drop. But a data packet, which is not realtime, can be transmitted or received at much lower rates. It may take 3 seconds to transmit a 1kB "PIN" message instead of .08 seconds, but who cares, as long as it gets through.
This happens to me a lot at my house, where I get a very weak signal on my cell phone and have trouble placing/receiving calls, but GPRS, SMS, and voicemail alerts work fine.