These instructions are notes how I managed to get Novatel Merlin XU870 express 34 to work on Ubuntu Gutsy. For additional information, check Novatel's webpages. I started the hassle by installing some software:
aptitude install gprs ppp pppconfig
Then I followed loosely the instructions from Novatel web pages and used pppconfig to configure the ppp interface for the card. This resulted in a PPP configuration which you extract to you /etc directory after taking back ups.
Finally, I use the following script to activate the GPRS interface:
#!/bin/sh
# dns: 193.229.0.40
sudo ifconfig wlan0 down 2> /dev/null
sudo ifconfig ppp0 down 2> /dev/null
sudo killall NetworkManager 2> /dev/null
read -p "(Re)insert gprs card and hit enter" temp
sleep 4
gcom -d /dev/ttyUSB0
sudo pppd file /etc/ppp/hsdpa_options
The limitation of this approach is that I have to reinsert the card when I switch from GPRS to WLAN and then back to GPRS. I haven't figured out how to overcome this problem yet. Also, it would be nice to make the NetworkManager to work with card in Ubuntu Intrepid.