NPR (New Packet Radio) is an hardware and software project by Guillaume F4HDK recently published on hackaday.io to carry IP network traffic over the amateur radio 70 cm band, with data rates of up to 500 kbps.
Despite the name, the NPR is not related to Amateur Radio Packet Network, and no AX.25 is involved. NPR project has been initially implemented as an extender of the HSMM Hamnet networks, and has been designed to work on 430 MHz.
While Packet Radio can efford at max 9600 bps on 144 MHz and 430 MHz, the NPR protocol can reach a raw bandwidth of 1 Mbps with an useful bandwith that goes from 150 to 600 kbps on the 430-440 MHz. Hammnet is capable to reach more than 10 Mbps on the 2.4GHz and 5.6 GHz.
NPR is intended to bring high bandwidth IP networking to radio amateurs in the 70 cm band, and it does this rather cleverly with a modem that contains a single-chip FSK transceiver intended for use in licence-free ISM band applications.
The NPR project includes an home made modem with a 433 MHz ISM module, connected with Ethernet to the PC that can be configure wither in client or master mode.
NPR features and limits
- Currently allow a maximum of 7 simultaneous clients
- 300km maxi (due to protocol)
- Limitations of 430MHz band:
- Not designed for 24×7 usage (The Master only transmits when solicited)
- Not designed for “mobile” operations
The NPR project includes an custom designed modem witha a price of 80 USD that can be configured either ad master or client device. Direct PC connection is possible via the built-in ethernet port and a network switch is not required. Initial configuration can be done either via USB port with a Serial terminal client or using the ethernet port via Telnet connection
NPR New Packet Radio Links
We’ve recently added a new category to our directory related to the NPR New Packet Radio Project and we will review more resources about this new digital protocol as soon will appear on the web
F4HDK has recently published this youtube video to demonstrate NPR New Packet Radio modem startup and connection status.