Openwifi project – what an open Wi-Fi chip looks like

2 min

We are talking about the first free distribution implementation of Wi-Fi 802.11a / g / n based on the software-defined radio system SDR (software-defined radio). Let’s talk about this project.

/ CC BY / Victor Aznabaev

What is this project

Most of the firmware for Wi-Fi devices are proprietary, so you cannot check if they have any backdoors. Specialists from the IDLab laboratory, formed on the basis of the Ghent and Antwerp universities in Belgium, decided to rectify the situation and launched the Openwifi project. This is an open source Wi-Fi FPGA implementation compatible with Linux. Engineers’ developments presented at the FOSDEM 2020 Free Software Conference.

The whole code with schemes hardware are on GitHub and are licensed AGPLv3… Although in this project several third-party modules were used – for example, commercial transceivers. Before you start working with Openwifi, you need to consider their licenses.

How does it work

System hardware based on Xilinx FPGA and radio transmitter AD9361… It also used the SoftMAC architecture, which implements the 802.11 wireless stack on the driver side. The mac80211 subsystem provided by the Linux kernel is responsible for this task. Scheme authors of the project placed in your repository.

The software part is based on OpenOFDM – open source implementation OFDM-decoder on Verilog. You can interact with the Wi-Fi module using standard Linux utilities – ifconfig and iwconfigas well as a specialized program sdrctl – it allows access to the Openwifi driver via netlink. The authors used the nl80211 and cfg80211 libraries to control wireless drivers from user space.

Among the main capabilities of the system, it is worth highlighting a 20 MHz bandwidth and a frequency range from 70 MHz to 6 GHz, time slicing by MAC address and protocol implementation. DCF on the FPGA side, which is the basic access protocol in Wi-Fi networks.

What are its prospects

Openwifi is in the early stages of development, so there is no need to talk about high bandwidth. Authors have achieved download speeds of 30.6 and 38.8 Mbps for TCP and UDP. The upload speed is slightly lower – 17.0 and 21.5 Mbit / s, respectively.

/ CC BY / Frank wang

In the future, the developers plan to increase these indicators. Adding support for the standard is also on their roadmap Wi-Fi 802.11ax… Overall Hacker News residents saythat Openwifi is another major step towards fully open hardware for wireless networking. It remains to implement the corresponding RF chip – the main thing is that there is no problems with patents various corporations.

What we write about in the corporate blog VAS Experts:


Leave a Reply