System Fusion Simplex calling freq

[avgas]

I am wondering if there has been any talk or implementation of a national C4FM calling frequency.

I know that D-Star has a couple simplex freq so I thought there might be something for Fusion.

Any info would be great, I didnt find much doing a search.

 

[N8OHU]

No single nationwide calling frequency, due to variances in band planning and availability.

 

[n9upc]

Many people in WI and some around the twin cities of MN have started to use 147.5250 Mhz as the VHF calling frequency. UHF has been a little bit of a mix and not to much of a worry as a fair amount of Fusion repeaters are popping up on UHF around western WI/twin cities MN.

 

[n9kww]

to new to worry about

Since the new Fusion system is s new and has a lot of growing pains to endure before it matures into a working system it will be quit some time before a simplex frequency will evolve. The main issue with Fusion is bandwidth, unlike the other digital modes (Dstar, Moto turbo/DMR, apco25 etc.) witch are narrow band, Fusion is wide band. Since it takes up a lot of real-estate RF wise, it will have to "commandeer" one of the existing analogue simplex frequencies. The nice part about the other digital modes is they have the ability to use frequency gaps between other users. They also have the ability to not disturb the current band plan in any significant way.
If you took a mode such as Dstar and put it into a current simplex frequency, you would and could have two simplex frequencies in essence. currently the typical simplex channel allocation is 15khz, since Dstar is only 6.5 kHz one could place to Dstar system in the place of one analogue system.
The fusion system uses 12.5 kHz with a guard band on each side it in essence uses the full 15khz bandwidth.
in short Fusion will have to take over one of the current simplex frequencies. In time that may in fact happen, but in my humble opinion I don't see that happening without a lot of very loud objections.
Ron
N9KWW

 

[N8OHU]

The only mode that is truly narrow is D-STAR; DMR (including MotoTRBO) Yaesu System Fusion, P25 Phase 2, and NXDN are all about 12.5 kHz wide. The simple fact is that digital mode simplex will have problems finding a frequency that can be standardized on everywhere.

 

[brushfire21]

Out of all of those NXDN 6.25 is the narrowest, DMR and P25 p1/p2 are are 12.5 (same as normal narrowband analog basically) I can't remember what DStar is but it's somewhere in between I think.

 

[N8OHU]

Out of all of those NXDN 6.25 is the narrowest, DMR and P25 p1/p2 are are 12.5 (same as normal narrowband analog basically) I can't remember what DStar is but it's somewhere in between I think.

Depends on if you go by what Icom claims, or what has been measured; I know Icom claims 6.25 for D-STAR (and the protocol specification actually wanted it narrower) and IDAS, but whether the latter actually is that narrow is hard to tell. I know some of the early D-STAR radios actually measured at something like 8 kHz wide, and I'm not sure if they've been able to get it down for the later models.

 

[brushfire21]

Not sure if your saying NXDN/ISAS/NEXEDGE is not 6.25, but I can assure it is. There are are NXDN bandwidths, 6.25 (Icom/kenwood) and 12.5 (kenwood only).

 

[N8OHU]

Not sure if your saying NXDN/ISAS/NEXEDGE is not 6.25, but I can assure it is. There are are NXDN bandwidths, 6.25 (Icom/kenwood) and 12.5 (kenwood only).

Like I said, that's the <b>claimed</b> bandwidth; has anyone actually measured the bandwidth of the Icom variant, like was done years ago for D-STAR?

 

[Aero125]

No single nationwide calling frequency, due to variances in band planning and availability.

Back to the topic - this plus other factors are discussed at length in the Yahoo Groups System Fusion group if anyone is interested. Also discussed is having a Wires-X simplex talk-in frequency to use while mobile to acess people Wires-X nodes.

 

[N0VGL]

The cool thing about System Fusion is that what ever mode a signal is received in, Fusion transmits it back in that same mode whether analog or digital.

 

[N8OHU]

The cool thing about System Fusion is that what ever mode a signal is received in, Fusion transmits it back in that same mode whether analog or digital.

A lot of folks want to avoid annoying analog users on the standard calling frequencies, this is why they want separate ones.

 

[N0VGL]

In my area, there are virtually no 2 meter simplex users who are on regular skeds. Virtually wide open.