Send data via IPv4 up to 300 kilometers with easy-to-assemble hardware
I have been a hobbyist and maker for almost 15 years now. I like inventing things and diving into low-level things. In 2013, I was looking at a protocol called NBP, used to create a data network over amateur radio links. NBP was developed in the 2000s as a potential replacement for the venerable AX.25 protocol [PDF] that’s been in use for digital links since the mid-1980s. I believed it was possible to create an even better protocol with a modern design that would be easier to use and inexpensive to physically implement.
It took six years, but the result is New Packet Radio (NPR), which I chose to publish under my call sign, F4HDK, as a nom de plume. It supports today’s de facto universal standard of communication—the Internet’s IPv4—and allows data to be transmitted at up to 500 kilobits per second on the popular 70-centimeter UHF ham radio band. Admittedly, 500 kb/s is not as fast as the megabits per second that flow through amateur networks such as the European Hamnet or U.S. AREDN, which use gigahertz
frequencies like those of Wi-Fi. But it is still faster than the 1.2 kb/s normally used by AX.25 links, and the 70-cm band permits long-distance links even when obstructions prevent line-of-sight transmissions.
Initially, I considered using different frequency bands for the uplink and downlink connections: Downlinks would have used the DVB-S standard, originally developed for digital satellite television. Uplinks would have used a variation of FSK (frequency-shift keying) to encode data. But the complexity involved in synchronizing the uplink and downlink was too high. Then I tried using a software-defined radio equipped with a field-programmable gate array (FPGA). I had some experience with FPGA READ FULL ARTICLE
Small multifunctional, digital, very compact amateur radio station for the radio operation at home, on the way or in the emergency radio. For the digi... Read more
his a ready power amplifier. You will need a power supply only! Water-cooled hermetically. You can turn the power amplifier. The water will not flow.... Read more
http://www.packtenna.com Read more
The RSGB have released a report on days 9 and 10 of the 2019 World Radiocommunication Conference being held in Sharm el-Sheikh, Egypt from October 28... Read more
Participants at the 45th meeting of the International Amateur Radio Union (IARU) Administrative Council (AC) in late September discussed the organizat... Read more
Nathaniel Frissell, W2NAF, now a University of Scranton physics and electrical engineering professor, has won a $1.3 million National Science Foundati... Read more
Well-known contester and DXpeditioner Paul H. Newberry, Jr., N4PN, of Macon, Georgia, died on November 5 after suffering a massive heart attack. An AR... Read more