# Huawei E1550 3G modem

## Introduction

This article describes how to configure Huawei E1550 3G modems.

This modem is generic modem device, but there are two kludges:

- you need to switch it into modem mode
- you need to load proper driver (usbserial)

## Prepare device

### Switch into modem mode

By default kernel recongnizes it as usb-storage device (SCSI CD-ROM). It is true, because of this modem contains MicroSD card (up to 4Gb) reader and internal flash.

To switch modem on you shoud run

    $ /lib/udev/usb_modeswitch --vendor 0x12d1 --product 0x1446 --type option-zerocd

command.

See also usb_modeswitch package in [community], which you may need in future since in udev-157 modem-modeswitch has been renamed and changed as described in the commit. This package does not need any modifications, just install it.

Also you can create udev's config: /etc/udev/rules.d/15-huawei-e1550.rules

    ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="12d1", ATTRS{idProduct}=="1446", RUN+="/lib/udev/usb_modeswitch --vendor 0x12d1 --product 0x1446 --type option-zerocd"

After that, modem changes its USB IDs to 12d1:140c and /proc/bus/usb/devices shows new USB endpoints.

### Driver loading

usbserial is proper driver for this modem, but probably it does not recognize it, so you shold force it, passing USB IDs.

     # modprobe usbserial vendor=0x12d1 product=0x140c

or put options into /etc/modprobe.d/modprobe.conf

     options usbserial vendor=0x12d1 product=0x140c

(do not forget to 'rmmod usbserial' if it is already loaded before)

### Optional: device naming

You can generate symlinks to the ttyUSB* ports for a more human readable configuration with udev rules.

For a Huawei device which identifies with the USB ID 12D1:1001 after modeswitching and has 3 serial ports:

     SUBSYSTEMS=="usb", ATTRS{modalias}=="usb:v12D1p1001*", KERNEL=="ttyUSB*", ATTRS{bInterfaceNumber}=="00", ATTRS{bInterfaceProtocol}=="ff", SYMLINK+="ttyUSB_utps_modem"
     SUBSYSTEMS=="usb", ATTRS{modalias}=="usb:v12D1p1001*", KERNEL=="ttyUSB*", ATTRS{bInterfaceNumber}=="01", ATTRS{bInterfaceProtocol}=="ff", SYMLINK+="ttyUSB_utps_diag"
     SUBSYSTEMS=="usb", ATTRS{modalias}=="usb:v12D1p1001*", KERNEL=="ttyUSB*", ATTRS{bInterfaceNumber}=="02", ATTRS{bInterfaceProtocol}=="ff", SYMLINK+="ttyUSB_utps_pcui"

For a Huawei device which identifies with the USB ID 12D1:1003 after modeswitching and has 2 serial ports:

     SUBSYSTEMS=="usb", ATTRS{modalias}=="usb:v12D1p1003*", KERNEL=="ttyUSB*", ATTRS{bInterfaceNumber}=="00", ATTRS{bInterfaceProtocol}=="ff", SYMLINK+="ttyUSB_utps_modem"
     SUBSYSTEMS=="usb", ATTRS{modalias}=="usb:v12D1p1003*", KERNEL=="ttyUSB*", ATTRS{bInterfaceNumber}=="01", ATTRS{bInterfaceProtocol}=="ff", SYMLINK+="ttyUSB_utps_pcui"

## Connecting internet

Now you have new 2 or 3 /dev/ttyUSB* devices.Most likely first of them (ttyUSB0 if you had not such devices before) is PPP compatible modem. Use it as usual with pppd, kppp, gnome-ppp, network-manager, etc.

Note: If you want to use your 3G modem with NetworkManager, you have to install the package modemmanager and then restart the `NetworkManager.service`. Now you can 'Enable Mobile Broadband' in the networkmanager applet.

## AT commands

There are some useful commands:

- AT^U2DIAG=0 - the device is only Modem
- AT^U2DIAG=1 - device is in modem mode + CD ROM
- AT^U2DIAG=255 - the device in modem mode + CD ROM + Card Reader
- AT^U2DIAG=256 - the device in modem mode + Card Reader
- AT+CPIN=<PIN-CODE> - enter PIN-code
- AT+CUSD=1,<PDU-encoded-USSD-code>,15 - USSD request, result can be found (probably) in /dev/ttyUSB2.

Encode "*100#" to PDU format:

     perl -e '@a=split(//,unpack("b*","*100#")); for ($i=7; $i < $#a; $i+=8) { $a[$i]="" } print uc(unpack("H*", pack("b*", join("", @a))))."\n"'

Decode "AA180C3602" from PDU format:

     perl -e '@a=split(//,unpack("b*", pack("H*","AA180C3602"))); for ($i=6; $i < $#a; $i+=7) {$a[$i].="0" } print pack("b*", join("", @a)).""'

Answer decoding (this example is balance response: 151.25):

     perl -e 'print pack("H*", "003100350031002C003200350020044004430431002E0020");'

Some operators return USSD result in PDU encoding, so you should check proper decoding method.

- AT+CSQ - get signal quality (AT+CSQ=?)
- AT+GMI - get manufacturer
- AT+GMM - get model
- AT+GMR - get revision
- AT+GMN - get IMEI
- AT+COPS? - get operator info
- AT^CARDLOCK="NCK-code" - unlock modem. NCK-code should be calculated by IMEI. After that modem can work with any GSM-provider.
- AT^SYSCFG=mode, order, band, roaming, domain - System Config

Mode:

- 2 Automatic search
- 13 2G ONLY
- 14 3G ONLY
- 16 No change

Order:

- 0 Automatic search
- 1 2G first, then 3G
- 2 3G first, then 2G
- 3 No change

Band:

- 80 GSM DCS systems
- 100 Extended GSM 900
- 200 Primary GSM 900
- 200000 GSM PCS
- 400000 WCDMA IMT 2000
- 3FFFFFFF Any band
- 40000000 No change of band

Roaming:

- 0 Not supported
- 1 Roaming is supported
- 2 No change

Domain:

- 0 CS_ONLY
- 1 PS_ONLY
- 2 CS_PS
- 3 ANY
- 4 No change

## Sending SMS

You can use gammu.

Edit ~/.gammurc

     [gammu]
     port=/dev/ttyUSB0
     connection=at
     name=huawei e1550
     model=

The run command:

     gammu sendsms TEXT +7123456789 -text qwe

## USSD Requests

Use huawei-ussdAUR[broken link: archived in aur-mirror] package. Or use ussd.php tool.

## Success Stories

2010-August-03: I didn't do anything, I just installed usb_modeswitch-1.1.3-2 and my kernel is 2.6.33. In the syslog (/var/log/messages.log) the usb_modeswitch can automatically configure the modem correctly but I still cannot connect to the internet using gnome network manager applet, then I installed the modemmanager package and restart the networkmanager service. Everything is working properly now.

## References

- USB 3G Modem
- Huawei E220

Category:

- Modems

Hidden category:

- Pages with broken package links