pi@hydra ~ $ lsusb 
...
Bus 001 Device 007: ID 19d2:2000 ZTE WCDMA Technologies MSM MF627/MF628/MF628+/MF636+ HSDPA/HSUPA
...
pi@hydra ~ $ 

pi@hydra ~ $ sudo apt-get install usb-modeswitch usb-modeswitch-data wvdial

pi@hydra $ lsusb 
...
Bus 001 Device 011: ID 19d2:0031 ZTE WCDMA Technologies MSM MF110/MF627/MF636
...
pi@hydra $ 

/etc/wvdial.conf

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 
Init3 = AT+CGDCONT=1,"IP","iijmio.jp"
Dial Attempts = 3
Stupid Mode = 1
Modem Type = Analog Modem
Dial Command = ATD
Stupid Mode = yes
Baud = 460800
New PPPD = yes
APN = iijmio.jp
Modem = /dev/ttyUSB2
ISDN = 0
Phone = *99#
Password = iij
Username = mio@iij
Carrier Check = no

pi@hydra ~ $ sudo wvdial
--> WvDial: Internet dialer version 1.61
--> Initializing modem.
--> Sending: ATZ
ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Sending: AT+CGDCONT=1,"IP","iijmio.jp"
AT+CGDCONT=1,"IP","iijmio.jp"
OK
--> Modem initialized.
--> Sending: ATD*99#
--> Waiting for carrier.
ATD*99#
CONNECT
--> Carrier detected.  Starting PPP immediately.
--> Starting pppd at Sat Apr  4 01:20:18 2015
--> Pid of pppd: 4415
--> Using interface ppp0
--> local  IP address 10.178.157.69
--> remote IP address 10.64.64.64
--> primary   DNS address 202.232.2.2
--> secondary DNS address 202.232.2.3

^CCaught signal 2:  Attempting to exit gracefully...
--> Terminating on signal 15
--> Connect time 1.1 minutes.
--> Disconnecting at Sat Apr  4 01:21:25 2015
pi@hydra ~ $