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
Specification Comparison
Summary
These five 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 extar and buy the BladeRF or LimeSDR. For those looking for a simple to use set-up and application, LimeSDR might be your best choice.