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
Assembled a prototype of Geckokapula V2 a dualband 70cm/13cm handheld FM/CW radio. It also does AM and SSB reception in addition to FM and CW. An awes... Read more
On May 30, operators at WX4NHC at the National Hurricane Center (NHC), working from home, conducted the annual readiness check of the station and of o... Read more
On Friday the 29th of May 2020, there was an extensive Sporadic-E opening across Europe which reached as high as 144 MHz allowing stations across the... Read more
Professional VHF UHF Radio: Dual band, dual watch, dual standby, up to 128 channels. Equipped with an 8.9-inch long antenna, this solid 5W radio can r... Read more
Jim W6LG your YouTube Elmer shows the progress on the MA40 Tower Installation that will be limited to 30 feet above the terrain as allowed by Ordinanc... Read more
Three strong winter storms (Petra, Sabine and Bianca) in February 2020 destroyed all the antennas of the Amateur Radio Remote-Station on the Mount Rig... Read more
Well-known contester, DXer, and National Contest Journal (NCJ) Editor Scott Wright, K0MD, has been “substantially” stepping back from ham radio while... Read more
The International Amateur Radio Union (IARU) Administrative Council has appointed Martin Sach, G8KDF, as global Electromagnetic Compatibility (EMC) Co... Read more
“This year’s ARRL Field Day adventure had me camping in the Flambeau River State Forest located in Northwestern Wisconsin and running as a... Read more
ANS-180 AMSAT News Service Weekly Bulletins for June 28th The AMSAT News Service bulletins are a free, weekly news and information service of AMSAT, T... Read more
The digital edition of the July/August issue of the National Contest Journal (NCJ) is now available for viewing on your desktop or laptop. Click here ... Read more