The new software requires a different DVB-T driver app to be installed first, which is also provided by Martin. This is because the RTL-SDR needs to be operated in a mode different to the way that the SDR drivers use it in. Martin has also open sourced his Android DVB-T driver and it is available on GitHub.
Aerial TV is currently free on the Google Play store, but looks like it may eventually have some in-app purchases. Also, it is currently marked as ‘Unreleased’ on Google Play, which is essentially a beta version, so you might expect there to be some bugs.
One nice feature of modern Motorola smartphones is that some models can accept ‘mods’, which are essentially phone cases that snap onto the back of the phone and interface via some exposed data pins. Some examples include a snap on speaker, projector, battery pack and zoom lens. Currently Moto Mods and Indiegogo are running a promotional campaign that gives developers a chance to pitch new Moto Mod ideas to Motorola, and if successful be partnered with Motorola and receive funding to complete and sell the hardware.
Vaclav Bouse is one developer who has been working on an RTL-SDR based Moto Mod. The idea is to integrate RTL-SDR hardware into the Moto Mod phone case form factor and possibly even add transceiver capabilities via an AX5043 transceiver chip. The hardware is still in the very early concept and design phases, and Vaclav is seeking donations on Indiegogo to help fund the development of a prototype (note that donating will not get you the final product). As it will be an RTL-SDR, it should be compatible with all Android RTL-SDR software, such as SDR Touch.
Over on YouTube the channel Budapest Hackerspace has recently uploaded a talk by Piotr Krysik which was given during the August 2016 Camp++ 0x7e0 information security conference. The talk is titled: “GSM signal sniffing for everyone with gr-gsm and Multi-RTL by Piotr Krysik” and talks about using the gr-gsm software and RTL-SDR dongles to sniff the GSM mobile phone network. Also, a tool developed by Piotr called multi-rtl which allows the proper synchronization of multiple RTL-SDR dongles in order to cover the large gap between the GSM uplink and downlink frequencies is discussed.
The talk explains a bit about how GSM works, and then goes on to talk about the gr-gsm and multi-rtl software. The talk blurb reads:
Gr-gsm is a set of tools for receiving GSM transmissions, which works with any software radio hardware capable of receiving GSM signal. Together with widely available RTL2832 based TV dongles, that are popularly used as low cost software radio receivers (known as RTL-SDR), it enables everyone to receive and study protocols used in GSM’s mobile radio interface.
Ability to receive signals spread over wide frequency range exceeding single RTL-SDR receiver’s bandwidth (~2.4MHz) was available exclusively for the owners of more capable and more expensive SDR devices. With introduction of Multi-RTL project by the author of the talk, this limit was overcome through synchronization of multiple RTL-SDR receivers in time domain, that doesn’t require complicated hardware modifications. With Muli-RTL it is possible to receive for example uplink and downlink of GSM900 transmissions, that are separated by 45MHz.
Speaker will present origins of both of the projects, together with description of their inner workings, examples of applications and plans for the future.
Over on YouTube user Crazy Danish Hacker has been working on uploading an entire series on GSM Sniffing with an RTL-SDR. His series is explained in a slow and clear presenting style, and it starts at the very beginning from installing the RTL-SDR. The tutorial series is not yet complete, however he is uploading a new video almost daily. Presumably the series will end with showing you how to receive text messages and voice calls originating from your own cellphone.
So far he has shown how to install the RTL-SDR, identify GSM downlinks, install and use GQRX and kalibrate, locate nearby cell towers, install and use GR-GSM and how to extract the TMSI & KC keys from your cell phone. To obtain the TMSI & KC keys he shows us how to use an Android tool called usbswitcher which forces the phone to use its USB modem interface, from which the keys can be obtained.
The video below shows his teaser video on the series. Check out his GSM playlist to view the full series.
A few months ago the popular SDRTouch software for Android added support for the SDRplay RSP. The RSP is a $149 USD software defined radio with a tuning range of 100 kHz to 2 GHz and a 12 bit ADC.
Over on YouTube user Mile Kokotov has uploaded a video showing the SDRplay RSP running in SDRTouch. He uses it to listen to the 14 MHz ham band in SSB mode and finds that reception is clear and that it is fairly easy to tune around.
In order to use the RSP with an Android device you will need a fairly modern phone and a USB OTG cable. Ideally try to get a USB OTG cable with an external power port as the battery can drain quite fast when using the SDR. SDRTouch also supports the RTL-SDR.
Over on YouTube user Osama SH has uploaded a video briefly showing the steps needed to use an RTL-SDR dongle to sniff some SMS text messages and voice calls made from his own phone. This can be done if some encryption data is known about the phone sending the messages, so it cannot be used to listen in on any phone – just ones you have access to. In the video he uses Airprobe and Wireshark to initially sniff the data, and find the information needed to decode the text message. Once through the process he is able to recover the SMS message and some voice audio files.
Previously we posted about Android programmer Tosis Nikolaos’s last app which was called “Track your flight Europe”. The app allows you to view aircraft tracked via ADS-B received by an RTL-SDR on an offline map.
Now Nikos has written into us once again to let us know about his new app called “Track your flight North America“. It is the same as his previous app, but this one has high resolution offline maps for North America. He also writes that his Europe app has also been updated to support high resolution offline maps. The app costs 5.09 Euros + VAT. To run it you will need an Android device and an RTL-SDR with OTG cable.
The post contains a full tutorial on the set up which involves the installation of ezstream and icecast for streaming audio as well as instructions for the installation of the modified version of rtl_fm called rtl_udp which allows remote control of the parameters via udp.