Welcome back, my aspiring RF hackers!

Before embarking upon the study of SDR for Hackers it is good idea to take a close look at the options available for hardware in this field. Of course, you will need a computer with a USB port but there are numerous options available for the radio receiver/transceiver. Let’s take a look at the specs and advantages and disadvantages each of the most common hardware options for software defined radio (SDR).

USRP

USRP is open-source hardware, firmware and host code making it an excellent choice for developers. USRP has multiple models with varying interfaces and sizes. The USRP X series uses 10g Ethernet interface, the USRP N series uses iG Ethernet, the USRP B series uses USB 2.0 (old) interface and USB 3.0 (new) and the USRP E series has a built in ARM processor and does not need a host computer.

The USRP B series is a favorite among developers as it uses USB 3.0 and the USRP B200mini is the size of a business card.

RTL-SDR

The RTL-SDR is among the most popular among hobbyists. It is low-cost, very capable and a good place to start in SDR for Hackers without making a major investment (less than $40).

It is based upon the DVB-T dongle that uses the RTL2832U chip. This dongle was originally used to watch TV on computers. The RTL-SDR supports many pieces of software based upon the library librtlsdr.

The RTL-SDR can be used to analyze signals and in combination with the HDSDR software can be used for a multitude of purposes.

The strength of the RTL-SDR is its low cost. The weakness of the RTL-SDR is that it is only a receiver and can not transmit signals such as in replay attacks.

 

HackRF

HackRF is great choice for beginners looking for an inexpensive SDR hardware that can both transmit and receive. Many “SDR for Hackers” projects require transmitting such as replay attacks.

HackRF is all open-source including its schematic diagram, PCB diagram, driver code, and single chip firmware. HackRF supports frequencies from 1MHz- 6Ghz. HackRF is only capable of transmitting and receiving at half-duplex, a major drawback for high performance systems.

 

BladeRF

BladeRF is a high performance hardware for the SDR for Hackers. Unlike HackRF, it is full-duplex making it ideal for high performance applications such as OpenBTS (OpenBTS is an open-source cellular base station). It’s only drawback is its frequency range. The BladeRF is only capable of sending and receiving radio frequencies to 3.8Ghz.

 

LimeSDR

LimeSDR is open-source, apps enabled SDR platform. It is capable of receiving and transmitting UMTS, LTE, GSM, LoRa, Bluetooth, Ziggbee, RFID and Digital Broadcasting and more.

One of the great strengths of LimeSDR is being apps enabled. LimeSDR is integrated into the Snappy Ubuntu core and anyone capable downloading and using an app can use the LimeSDR. This makes its capabilities available to a much wider audience. EE, the UK’s largest mobile operator is distributing LimeSDR to educational institutions for training and development. Apps available for the LimeSDR include;

• Radio astronomy
• RADAR
• 2G to 4G cellular base station
• Media streaming
• IoT gateway
• HAM radio
• Wireless keyboard and mice emulation and detection
• Tire pressure monitoring systems
• Aviation transponders
• Utility meters
• Drone command and control
• Test and measurement

SDRplay RSPdx

The SDRplay RSPdx offers the user a better dynamic range and sensitivity than the RTL-SDR dongles. This becomes important in crowded RF spaces or where the signals are weak.

The SDRplay is excellent for aircraft tracking, receiving NOAA weather satellite images, listening to FM radio, and receiving weather balloon telemetry, and scanning trunked radio systems.

LibreSDR

The LibreSDR is one of the newest SDR’s on the market. It is a USRP B220 clone making it a powerful transceiver for all types of SDR work. It uses the AD9361 RF transceiver, the same as the Ettus Research USRP b210/220. This makes it ideal for private cellular network development, RF experimentation, and signal analysis. The LibreSDR is popular as the core of cellular cores like Open5GS and srsRAN. Since they are clones of the USRP they get the performance of these advanced SDR’s without the high-cost.

 

Specification Comparison

 

Summary

These seven hardware platforms offer a wide-range of capabilities and prices for the hacker looking to get into SDR. We recommend RTL-SDR for those just starting out and on a limited budget. For those looking to hack radio signals, you will likely need a transceiver and the HackRF One is an excellent platform at a reasonable price. Those needing high performance and full duplex will likely want to spend a little extra and buy the BladeRF or the LibreSDR For those looking for a simple to use set-up and application, LimeSDR might be your best choice.