33C3 talk on dissecting cellular modems

Yesterday, together with Holger 'zecke' Freyther, I co-presented at .

This presentation covers some of our recent explorations into a specific
type of 3G/4G cellular modems, which next to the regular modem/baseband
processor also contain a Cortex-A5 core that (unexpectedly) runs Linux.

We want to use such modems for building self-contained M2M devices that
run the entire application inside the modem itself, without any external
needs except electrical power, SIM card and antenna.

Next to that, they also pose an ideal platform for testing the Osmocom
network-side projects for running GSM, GPRS, EDGE, UMTS and HSPA
cellular networks.

You can find the
in case you're interested in more details about our work.

The results of our reverse engineering can be found in the wiki at
http://osmocom.org/projects/quectel-modems/wiki together with links to
the various git repositories containing related tools.

As with all the many projects that I happen to end up doing, it would be
great to get more people contributing to them. If you're interested in
cellular technology and want to help out, feel free to register at the
osmocom.org site and start adding/updating/correcting information to the
wiki.

You can e.g. help by

• playing with the modem and documenting your findings




• reviewing the source code released by Qualcomm + Quectel and
  documenting your findings




• help us to create a working OE build with our own kernel and rootfs
  images as well as opkg package feeds for the modems




• help reverse engineering DIAG and QMI protocols as well as the open
  source programs to interact with them