A while back, Yaesu published a white paper/brochure on VHF/UHF digital technology that slammed D-STAR for using GMSK modulation and stated that C4FM (4-Level FSK) is the way to go. See my previous posting on that topic. The paper also talked about DMR and APCO 25 as standards that use C4FM.
Page 14 of the document says:
At this point in time Vertex Standard believes the C4FM (4-level FSK) FDMA or TDMA are the most suitable selections for Amateur radio applications. In early 2012, we will release a C4FM (4-level FSK) FDMA Handy-Talky and a Mobile transceiver into the Amateur radio market. After our initial introduction, we plan to introduce a C4FM (4-level FSK) TDMA (2 slots) or TDMA Handy and Mobile transceiver into the Amateur market.
This led to speculation that we would see a Yaesu DMR or APCO 25 radio at the Dayton Hamvention. The topic was hotly debated in various online forums, with the prevailing theory being that it would be a DMR radio to play and compete with Motorola’s MOTOTRBO™ radios. It now seems that the initial introduction is the FT-1D, a dualband handheld that just does analog FM and a plain C4FM digital format (no DMR or APCO 25 protocol). This blog has the product brochure for the FT-1D. (Click on “Page 1” and “Page 2” links.)
The general reaction from the ham radio community is WTF, over? I don’t know why anyone would buy a radio to use with digital C4FM modulation. This digital mode is incompatible with D-STAR, DMR and APCO 25…the most common digital formats on the VHF/UHF ham bands. The quote listed above indicates that there will be more coming from Yaesu later in the year, that includes TDMA. This could be DMR but who knows?
– 73, Bob K0NR