I live in Rangsit. I use both True and Dtac on 2 different Nokia mobile phones. Quite often the sound quality while talking is disturbed by a kind of noise. Sometimes other people cannot hear me, sometimes I cannot hear other people talking. Is this common for Rangsit, or what else could this be ?

I use AIS and never have a problem.

Mobile is crystal clear for many years

I use AIS, and I find the signal is spotty in Pinklao, because it's not downtown. I can only see one cell tower as far as I can see (I'm in a tall condo building), so I blame it on that. Maybe it's the same thing in Rangsit?

I used to have True, but the signal here was even worse.

If you have a smart-phone or a pda-phone (anything with Windows mobile), go into wireless manager, choose phone settings from the menu, go to the network tab, and choose "find network". This will re-sign you into the network, and might give you an EDGE or GPRS connection. If your signal indicator doesn't have a G or an E next to it, you might be calling through an analogue connection, which has the worst call quality.