Just got my day-pass option with t-mobile under Linux and my HUAWEI USB-Stick HDSPA-Modem (lists as Huawei Technologies Co., Ltd. E220 HSDPA Modem / E230/E270 HSDPA/HSUPA Modem in lsusb) running. Now I pay $2 per day, if I need Internet on that day (only 2G speed - I measured, I got something around 9-16Kbytes per second - enough to even use Skype). For $3 a day you get even 200MB on 4G speed. Nice is that the connection is apart from the speed not capped. Pretty good prepaid optionin the US. I got a second SIM-card for this purpose (didn't want to lose my gold status on my "normal" prepaid card).
Basically all you need is the wvdial-package and the following in /etc/wvdial.conf:
[Dialer Defaults] Init1 = ATZ Init2 = AT+CGDCONT=1,"IP","epc.tmobile.com" Modem Type = USB Modem Modem = /dev/ttyUSB0 Baud = 460800 Phone = *99# Password = pass Username = user ISDN = 0 New PPPD = yes Stupid Mode = yes
Make sure, that your modem is on /dev/ttyUSB0 (you might end up on a differnt USBn, if you have a built in modem). Took me a while to figure out how to specify the access point (epc.tmobile.com) and had to read this one out on my Android phone.
Just start wvdial now and it should connect.
You might also want to make sure that your user is in the dialout group or you will have to start wvdial as root.
You might also try as root before starting wvdial (not sure, if the storage module here interferes):
rmmod usb-storage rmmod option rmmod usbserial qcserial usb_wwan modprobe usbserial vendor=0x12d1 product=0x1003
However, I think this is not necessary, if you select the right USB-port (I have a qualcomm modem built in).