I am working with an embedded Linux host running a network application that works fine using a cabled Ethernet connection for Internet access (through DSL or an external 3G router). I want to make it work mobile without the external 3G router, by using the MC8305 installed in a PCI Express Mini Card socket on the device. I can see that the modem is connected by USB, create a COM port device (/dev/ttyUSB2), and send it AT commands with microcom. I have a SIM card from Wyless (T-Mobile service) installed, and can read it like this:
In the past I have used a MC5728 (CDMA) modem and been able to use “ATDT#777” to make a data connection (using a chat script) and use pppd to create the network interface. But in this case I get:
If there is no SIM card installed, it returns “ERROR”, so that is progress But I now need to know how to take the next step. I think I might need some combination of:
- Do GSM registration
- Set up the APN
I see lots of postings in the Sierra forums about how to do networking using Open AT, but I am not looking to run an application on the modem itself, just use the modem as a modem. Could someone suggest what the next steps I need to take might be? Is using ppp the best option, or is there a more direct way to get a Linux network interface device? Is this the best forum to ask these questions in?