Hi, I use a 3G usb modem, I have 2, but use only one.
When I started wvdial was recommended, it never worked for me. (No offence intended, it obviously works well for many, as I have read.)
I wonder, are you able to get the dns addresses, gateway address, speed (etc) for your device and ISP?
(also the kernel module-name required) mine uses the option module.
if so you may be able to set up the device without wvdial.
The config files are in
/etc/resolve.conf (for dns's)
/etc/sysconfig/network-scripts (for ifcfg-ppp0, chat-ppp0, ifup-ppp0 script pin-ppp0 (password, empty on my system as it is governed by the sim card)/etc/ifplugd/ifplugd.conf, /etc/sysconfig/network, /etc/ppp/peers/ppp0)
I was fortunate to have a version of M$win and was able to check the config files there, like netstat /an (-an for unix like systems) and route -n (/n for M$win) and a bit of web searching came up with the goods, But I had to load it from /etc/rc.local to initialise it at boot.
I hope this give you an avenue to search for, I have no idea about your type of modem, but if you'd like to see these config files I have listed, just ask.