Why no ham market options for P25?

[mm]

Good grief I need a beer, some of these RR threads give me a headache.

Perhaps another elitist thread is going to be starting from this, let the flame wars begin I say, in reference to a closed P25 repeater that is but that's your buisness.

Just run the damn repeater in mixed mode, wide FM and narrow digital mode and be done with it, why closed anyway ?

To the subject of wideband/narrowband:
None of the new radios use any type of discrete IF filters anyway, anymore so WB NB concerns are not a matter.

These days all of the NB and WB filtering is done in an FPGA so it's simply written in software to restrict certain operating ranges to WB or NB exclusively.

To keep software cost down the manufacturers write their code to support both Wide and Narrow IF bandwidths(in software), and this is what KS4VT mentions that the radio will still support WB and NB in certain frequency ranges an only NB in others.

My company aside from designing Avionics equipment, we also design marine band radios in the 156 +- range and as far I remember none of my designs are NB and nothing on the drawing board says I have to do any NB changes so hence the other commercial guys, Moto, Thales, Harris,Cobham, technisonics etc will still need to support WB in these non part 90 ranges especially with certain Govt agencies purchasing some of these radio, the other govt. users still need to talk to the guys with single band marine only radios.

The APX and other MFG radios still need to support WB deviation at this time and I seriously doubt that the MFG's will write entirely new code for the FPGA when 2013 comes around, it's much to expensive to do and way to risky to do on a production product, they will simply enable or disable sections of code that's already been tested.


Mike

 

[W2NJS]

The short answer to the OP's question, now that I think about it some more, is that in my area there are maybe 50 U and V repeaters I can hit. There may be even more. Fact is that right now only TWO of these machines are P25 and there are maybe, I say maybe, 15 or 20 hams who can and do use them. The demand is currently low for the service, but it is building, and in time that demand will expand. Nothing beats the reception of a properly designed and adjusted P25 repeater, believe me, because it is noiseless and natural sounding and as the word gets out about how good it sounds there will be more P25 repeaters available and more people using them. As far as equipment goes, we've all heard of the new P25 HT due out soon from Vertex which would seem to me that the manufacturers are interested in this market.

 

[Nap]

Why would you as a radio amateur want to use a proprietary, patented, unusual method of communication when you have well known, largely available alternatives of similar or better performance? For experimentation and learning, yes sure, but inflicting it to everyone around through a repeater?

 

[mancow]

Because I can, and because without innovation the hobby becomes stagnant and boring.

 

[W2NJS]

"Inflicting it to (sic) everyone around through a repeater?" I thought we had the choice of using a repeater or not using it.
"Of similar or better performance.?" You obviously haven't done any P25 listening on a good system.

Are you serious? Ham radio was/is based on new modes, innovation, etc. As Casey so aptly put it, the reason is because I can.

For anyone who doesn't care to go P25, note the repeater ratio of about 25 to 1, FM to P25, that I used in my example. There's plenty of room for everyone to do their own thing in amateur radio so let's keep the doors open without criticizing the avenues of experimentation and operation that others elect to use.

 

[mikewazowski]

Well said.

I could use a stagnant form of communications or experiment with new technology.

 

[Nap]

Because I can, and because without innovation the hobby becomes stagnant and boring.

I do not agree that using a canned, closed, existing commercial solution is called innovation.

In my book it would be developing a new, competitive digital codec and sharing it with the community for experimentation, enhancements and enjoyment.

 

[mancow]

Canned closed? An IMBE astro saber on ebay can be had for far less than any decent hammy rig. If you want to talk about canned and closed DSTAR fits that bill nicely.

 

[Nap]

I wasn't advocating D-star either.

With both, you buy the radio and can switch between analog and digital voice. So what. I can't see anything cool beyond hearing how your voice sounds through the codecs.

OTOH if there is anything in P25 or Dstar that you want to use creatively (like let's say using the data capabilities and creating some sort of over-the-air mini-internet around your repeater with your friends) then more power to you.

As for the voice codec itself, developing something like this:

Codec 2 « Rowetel

looks like the way to go.

 

[W2NJS]

So, should we all infer from your most recent post that your anti-P25 remarks are actually based on your desire to promote yet another digital mode of communications? That would be a real stretch from criticizing hams for their P25 interest and use. Three established digital modes, P25, D-Star, and TRBO are more than enough for me right now.

 

[Nap]

I'm not promoting anything. What I'm trying to say is that buying a commercial product, turning it on and speaking in the mic is not "innovation". It is "communication" which is a major aspect of ham radio, but let's please not call it "innovation".

 

[mancow]

So doing nothing but dragging around a 20 year old HTX202 is the way to go? Have you never heard of the callsign routing of DSTAR or the networking of TRBO or the TMS messaging and signalling enhancements of P25?

 

[WayneH]

... but let's please not call it "innovation".

How is operating P25, TRBO, NXDN, etc not innovative? In this case you're introducing various digital technologies to the stale world of amateur radio. With the equipment being commercial there's a much better chance the equipment will be properly tuned and not over-modulate or be off freq like some of the junk that's currently marketed to amateur radio. I think you have a hidden agenda here.

Just because P25, et al, has been out for a while doesn't necessarily make it out of the realm of being innovative when it's brought to a new arena to show off. It's not like there are a plethora of P25 repeaters all over the place.

 

[Nap]

So doing nothing but dragging around a 20 year old HTX202 is the way to go?

If your need is to communicate, a plain, well established analog mode gives you more chances to reach someone that can receive/understand your transmission.

 

[Nap]

How is operating P25, TRBO, NXDN, etc not innovative? In this case you're introducing various digital technologies to the stale world of amateur radio.

If we're referring to the voice part, it's as innovative as introducing a new voice scrambling method.

I have yet to see a serious study showing how these voice modes are dramatic improvements in distance, intelligibility, robustness in high noise conditions, or power requirements over good old analog AM/FM/SSB.

As they're nothing but the equivalent of doing VOIP over a dialup modem over a telephone - instead of talking directly into the phone. The underlying carrying technology - the phone line - has remained the same.

What is really interesting when you are adding the modem is that you now can have various DATA modes, and depending on how you design/program the modem, you can achieve some interesting goals like a reliable link under adverse noise conditions.

A look at this site:

Software for digital modes

shows some innovation going on. It's not a "stale" world.

 

[WayneH]

I have yet to see a serious study showing how these voice modes are dramatic improvements in distance, intelligibility, robustness in high noise conditions, or power requirements over good old analog AM/FM/SSB.

I wouldn't say the improvements are dramatic but given two properly tuned systems, P25 will give the same range and in some conditions provide better recovery of voice at the fringe of coverage.

But, the biggest benefit to digital communications is the reduction in bandwidth, and THAT is what amateur really needs. No one needs to be running a 25kHz split channel anymore.

P25 was fun when it first started but I think NXDN and TRBO are where it's at. The equipment is cheaper to purchase along with the programming hardware being cheaper (that's a dent in P25). Plus, simple IP connectivity for TRBO and NXDN makes linking and RX voted systems very easy to do. Nothing simple about linking P25.

 

[JRayfield]

MOTOTRBO is not just another 'radio system'. It's much more 'computer' than 'radio'. It's definitely not just "VoIP" on RF, although that is a simple way to describe it to those who don't understand the underlying technology in it.

Engineering math shows that MOTOTRBO has a definite 'advantage' over analog FM. The 'math', as well as on-the-air testing, shows about a 3db improvement over wideband analog FM, and a 6 to 8 db improvement over narrowband analog FM. I've had discussions about this with one of the best RF propagation engineers in the U.S., and these are the conclusions that he came to, based on the 'math'.

There was also a discussion of this on the Batlabs forum, sometime in the last year.

John Rayfield, Jr. CETma

If we're referring to the voice part, it's as innovative as introducing a new voice scrambling method.

I have yet to see a serious study showing how these voice modes are dramatic improvements in distance, intelligibility, robustness in high noise conditions, or power requirements over good old analog AM/FM/SSB.

As they're nothing but the equivalent of doing VOIP over a dialup modem over a telephone - instead of talking directly into the phone. The underlying carrying technology - the phone line - has remained the same.

What is really interesting when you are adding the modem is that you now can have various DATA modes, and depending on how you design/program the modem, you can achieve some interesting goals like a reliable link under adverse noise conditions.

A look at this site:

Software for digital modes

shows some innovation going on. It's not a "stale" world.

 

[Nap]

But, the biggest benefit to digital communications is the reduction in bandwidth, and THAT is what amateur really needs. No one needs to be running a 25kHz split channel anymore.

We have SSB for a long time now, and I have some people in my area experimenting it on VHF/UHF. 3kHz bandwidth is not bad at all. Yes it makes "funny voices" but so does digital when restricting bandwidth to the extreme.

Plus, simple IP connectivity for TRBO and NXDN makes linking and RX voted systems very easy to do. Nothing simple about linking P25.

I always agreed that the IP/data aspect is worth investigating. If this is what you want to do, more power to you.

 

[rfradioconsult]

As a group we need to be giving serious cosideration to technologies that will enable us (HAMS) to embrace the very real possibility of our Amateur bands being sold to the highest bidder, if we are lucky our 2 Meter allocation may be severly reduced to maybe one Megahertz or less. We know the 2 meter band is underutilized in most of the U.S. and a well positioned corporation could give a compelling reason for the FCC to auction it off.

Imagine a large corporation let's call Goverment Motors or GM promotes a vehicle wireless system than can be used to monitor owner's vehicles, unlock doors, track the vehicle, etc. They currently use the exisitng nationwide cellular network and have decided they want to buildout their own network and decided their most cost effective network would be the 2 Meter band and they could operate their network with 3.5 Megahertz of bandwidth.

They recruit some ungrad EE's send them around the country to conduct a survey of 2 Meter activity, sort of a Google Street View team. We could kiss our beloved band goodby.

We need to be innovative in our process old WideBand FM technology will be soon going the way of vacuum tubes, cassette tape, LP's, VHS, take your pick.

 

[mancow]

Or, they pay off a couple congress members and FCC members.