Yaesu System Fusion Info
What is System Fusion C4FM?
Yaesu System Fusion is--you guessed it--Yaesu's digital voice mode included in the majority of their current line of VHF and UHF radios. System Fusion C4FM is one of many digital modes; but it is also probably the easiest to use. To get up and running, all you need do is set the mode and enter the frequency and you are ready to go. There is no registration, and no 'code-plugs.'
System Fusion Radios
There is a long list of Yaesu radios which support System Fusion. The handhelds include the FT70D, FT1D, FT2D and FT3D. The mobiles include the FTM-100D (sadly, discontinued), FTM-400(X)D, FTM-300, FTM-3200D, FTM-3207D, and FTM-7250D. Even the FT-991A supports Fusion on 2m and 70cm. As you probably tell, this is includes nearly all of the Yaesu VHF/UHF radios currently on offer.
System Fusion Modes
Altogether, System Fusion has three different modes: digital-narrow (DN), voice-wide (VW), and analog FM.
Digital-narrow uses 12.5K bandwidth in total, 6.25K for voice and 6.25K for data. The data portion of the transmission includes your callsign and location (location information can be suppressed in settings), and can also include text messages or even pictures. The voice codec used in DN mode is DVSI's AMBE+2, the same as DMR or NXDN.
Voice-wide also uses 12.5K of bandwidth, but all of it is devoted to voice (and error correction). You callsign is still transmitted as a short data burst at the beginning on each transmission, but no location information or any other data is passed. VW provides greater voice quality due to having more bandwidth devoted to voice data. The voice codec used for VW is DVSI's IMBE, the same as P25.