Re: Loss of signal / Missed calls
Loss of signal can be many things. The most frequent thing is the limited cell signal in the area. If you know someone with the same carrier service ask if they have issues. If you can do it when your together in the area. Check your signal strength vs. theirs on the phone. If you show limited or none and they show good you may have a hardware issue. In some instances an App can cause conflict if it's constantly doing a network download. Facebook etc.
You can also try a battery pull and wait for a couple of minutes and replace. It will do a clean reboot.
Last resort is hardware.
Z10 on BES
Z10 on BIS