Lately, I have been experimenting with using a CC1101 chip together with a Beaglebone black single board ARM computer to transmit IP traffic over the 70cm Amateur band. There has been a similar project from OEVSV, but I've never seen this project reach a final form. Edouard F4EXB has some code that uses the Raspberry Pi instead. Presumably, this will suffer from problems when using the higher data rates supported by the CC1101, as his software is not real-time.
The goal of my project is to build an affordable 70cm IP transceiver with a power of a few Watts. This can be used in the Hamnet Amateur Radio IP network. The modulation should not use more than a couple of hundreds of kHz's of spectrum, as it doesn't seem very sensible to take up much more spectrum in the 70cm band. Although the usual maximum bandwidth in the 70cm band is 20kHz, the IARU R1 bandplan allows for wideband experiments around 434.000MHz. A data rate of 128kbps with MSK modulation seems about right, as it uses roughly 200kHz of spectrum. Further on-the-air tests will perhaps change these parameters a bit.