Access Modem - Android Device (Nexus 5)

Question

Device : Google Nexus 5 (Un-rooted)
Host Machine : Window 7

I want to Access Android Device as a Modem (using COM or Modem Port) and eventually pass AT Commands using HyperTerminal/Teraterm.

So after connecting the device to a Windows Box, The Device gets detected under Device Manager, but doesn't show any COM Port (other than the default COM0).

On right click and update driver, It shows it cannot find drivers.

I have tried the following options, but no luck with any.

1. Tried this on a rooted Nexus 5, but doesn't expose which /dev/smdX to use. Tried all combinations, didn't work.
2. Tried the Google USB Drivers from the Google Android's Website. No changes.
3. From here. I Installed drivers from LG Electronics, No changes in COM Port.
4. Universal Naked Driver helped me get to ADB Shell interface, but thats not what I want.

In all of the Above procedure USB Debugging was enabled (Just saying).

I also heard the phone has to put into Modem mode to fire AT Commands. If so, How do I do that ?
Or Is this a device driver Issue ?

Conclusion:
I want to access the Modem of the Android Device and fire AT Commands to it.

Could you please tell what am I missing ?
Any help on this would be really appreciated.

Answer 1

It's difficult to give an exact answer to this question, because it depends on how the manufacturer has implemented the device drivers. Unfortunately, there is a lot of information that isn't in the public domain.

It is possible, that the manufacturer has implemented some code to convert the device to a modem. Doing this yourself is device-specific, and proprietary. You might be able to get hold of a converter, for example bundled with the manufacturer's dashboard application for the PC, if such a thing exists.

Some devices don't expose the modem port at all. They may be visible as a network adapter, or as an always-connected LAN connection. If the device is visible as a network adapter, then you can access it via Windows Mobile Broadband API, or via MBIM for some newer devices.

To check if the device is visible as a network adapter, and get information about it, open a cmd box and type

netsh mbn show interfaces

Windows Mobile Broadband API doesn't give as many details as a good AT command set, but performs basically the same functions. MBIM is an industry standard interface with similar functionality, available on the Windows 8+ desktop via the Mobile Broadband DeviceServices API, for devices that support it.

If the device shows as an always-on LAN connection, there is probably a proprietary, high level interface for mobile functionality.

Driver behaviour can differ for different operating systems. If you have the chance to try the device on Windows Vista, 7 and 8, you may see different behaviour.