3g

34 Articles

Wireshark screenshot with QCSuper-produced packets streaming into it; QCSuper script running in an adjacent terminal

Turn Your Qualcomm Phone Or Modem Into Cellular Sniffer

April 30, 2024 by 16 Comments

If your thought repurposing DVB-T dongles for generic software defined radio (SDR) use was cool, wait until you see QCSuper, a project that re-purposes phones and modems to capture raw 2G/3G/4G/5G. You have to have a Qualcomm-based device, it has to either run rooted Android or be a USB modem, but once you find one in your drawers, you can get a steady stream of packets straight into your Wireshark window. No more expensive SDR requirement for getting into cellular sniffing – at least, not unless you are debugging some seriously low-level issues.

It appears there’s a Qualcomm specific diagnostic port you can access over USB, that this software can make use of. The 5G capture support is currently situational, but 2G/3G/4G capabilities seem to be pretty stable. And there’s a good few devices in the “successfully tested” list – given the way this software functions, chances are, your device will work! Remember to report whether it does or doesn’t, of course. Also, the project is seriously rich on instructions – whether you’re using Linux or Windows, it appears you won’t be left alone debugging any problems you might encounter.

This is a receive-only project, so, legally, you are most likely allowed to have fun — at least, it would be pretty complicated to detect that you are, unlike with transmit-capable setups. Qualcomm devices have pretty much permeated our lives, with Qualcomm chips nowadays used even in the ever-present SimCom modules, like the modems used in the PinePhone. Wondering what a sniffer could be useful for? Well, for one, if you ever need to debug a 4G base station you’ve just set up, completely legally, of course.

2G Or Not 2G, That Is The Question

November 8, 2023 by 66 Comments

Since the very early 1990s, we have become used to ubiquitous digital mobile phone coverage for both voice and data. Such has been their success that they have for many users entirely supplanted the landline phone, and increasingly their voice functionality has become secondary to their provision of an always-on internet connection. With the 5G connections that are now the pinnacle of mobile connectivity we’re on the fourth generation of digital networks, with the earlier so-called “1G” networks using an analogue connection being the first. As consumers have over time migrated to the newer and faster mobile network standards then, the usage of the older versions has reduced to the point at which carriers are starting to turn them off. Those 2G networks from the 1990s and the 2000s-era 3G networks which supplanted them are now expensive to maintain, consuming energy and RF spectrum as they do, while generating precious little customer revenue.

Tech From When Any Phone That Wasn’t A Brick Was Cool