Daniel Estévez EA4GPZ / M0HXM has been investigating NPR, an open-source modem designed to carry IP traffic over the 70cm Amateur Radio band, with data rates of up to 500 kbps
The goal of this modem is to be used for the Hamnet Amateur radio IP network, to give access to end users where coverage on the 2.3 GHz and 5 GHz bands is poor due to the terrain.
Overall, Daniel think that NPR is a great project. In its present state it is already a useful kit that anyone can build. It is also a very nice platform to study and experiment with TDMA, and its protocol can be modified and improved further. It is also completely open-source.
Daniel Estévez EA4GPZ / M0HXM Blog - https://destevez.net/2019/04/npr-hamnet-over-70cm/