Feds pushing Project 25

[16b]

I don't know how many different ways I am going to have to say this before it clicks with certain people, but here goes.

I'm not complaining about P25. I'm not complaining about digital. I'm not complaining about the standards committee and their decisions.

- Digital is inevitable. We can argue all day about whether it's good or not, but it's inevitable. Sort of like FM, I think that most radio will eventually be digital. Looks like it's already happening in Japan.
- Standards are good. Eventually, when everyone is on digital, it will be important to have common protocols.

The gist of the *original post* was that the feds are saying "Interoperability is not as good as it should be. The solution: use P25." This is a lie. Read that again. It's a lie.

The point brought up by folks like Elroy and me is that the *frequency band* is a bigger problem than the protocol being used. Everyone using a radio right now has analog capability. Obviously, they are not all able to communicate with each other. Switching to P25 will not improve this.

 

[N_Jay]

Where did the "digital is less expensive than analog" discussion go? Did I miss it? Looking at news articles about the cost of new digital trunking systems, the prices seem rather astronomical. And now there is talk of those systems having an expected life cycle perhaps 30% less than first expected (and budgeted by agencies). My opinion (and it's not worth anything except to me) $$$$$$$$$$$$$$$$$. (Translated: vendors are making mega-bucks off this, with no end in sight.) 'Tis the american way I guess.

I would think that it would be easy to show how even now, some configurations of P25 are no more expensive than there equivalent configuration of analog system.

 

[N_Jay]

Not a typo but rather the wrong word. A typo would be like "tehir", for example.
In the instant case, it is just wrong or maybe from the appendage of the name calling,
the result of ignorance. I've found in my many years that folks who resort to
name calling are usually those of lesser minds.

typographical error
(typo) An error while inputting text via keyboard, made despite the fact that the user knows exactly what to type in. This usually results from the operator's inexperience at keyboarding, rushing, not paying attention, or carelessness.

 

[N_Jay]

. . .
The point brought up by folks like Elroy and me is that the *frequency band* is a bigger problem than the protocol being used. Everyone using a radio right now has analog capability. Obviously, they are not all able to communicate with each other. Switching to P25 will not improve this.

However, analog was only interoperable in conventions with almost all features disabled.

P25 is interoperable across the entire range of its features.

 

[WA4MJF]

There and their are two different types of words with
two different meanings. You can spin it how you would
like to,
but it is NOT a typo, just as using your when one means
you're. It is a sign of the lack of knowledge of American
English.

 

[N_Jay]

There and their are two different types of words with
two different meanings. You can spin it how you would
like to,
but it is NOT a typo, just as using your when one means
you're. It is a sign of the lack of knowledge of American
English.

I did not "spin" anything.

I pulled up a definition that included a range of error including mine of " . . . not paying attention, or carelessness . . ."

Sorry if that bothers you; your imperial perfectness!:roll: :roll:

EDIT:

OK, so some might call it a a "thinko" instead.

http://ase.tufts.edu/cogstud/papers/Dennett_From_Typo_to_Thinko.pdf

 

[Raccon]

There and their are two different types of words with
two different meanings. You can spin it how you would
like to,
but it is NOT a typo, just as using your when one means
you're. It is a sign of the lack of knowledge of American
English.

Give it a rest. It doesn't matter if it was a typo or the wrong word, the statement could still be understood. If the wrong word changes the meaning or facts of a statement than you may have a point, but this isn't the case.
Calling other people on such is bad form and off-topic, just leading to the back-and-forth bull**** that is going on now, which brings no value to the discussion.

Next time send a PM or just leave it. Over and out.

 

[WayneH]

Guys, this isn't English 101. There are people who have poor grammar and there are people that make typos. The latter does not deserve grammar nazi remarks.

 

[WA4MJF]

Well, in a forum where the written word is the medium for discussion,
then folks should be precise in their use of words. Using typo as an
excuse for ignorance just doesn't cut it. If he had just said "I don't know
the difference between a possessive pronoun and an adverb/non possessive
pronoun" and not added the name calling at the end, a sure sign of a
shallow mind, I wouldn't have written anything.

 

[N_Jay]

Well, in a forum where the written word is the medium for discussion,
then folks should be precise in their use of words. Using typo as an
excuse for ignorance just doesn't cut it. If he had just said "I don't know
the difference between a possessive pronoun and an adverb/non possessive
pronoun" and not added the name calling at the end, a sure sign of a
shallow mind, I wouldn't have written anything.

I don't type well, and I often don't reread my post (beyond hitting the spell check).

I most certainly know the difference between "there", "their" and "they're", but my fingers get ahead of my brain and I often type "there" for any of the three and have to fix it after the fact.

It was a simple mistake.

AND,

The "*******" comment stands!

 

[loumaag]

...The "*******" comment stands!

Actually you know better than this! I guess the color choice had me miss it initially on my screen (my problem and fixed as of now). This is not the tavern and you know we will not stand for the bickering I see going on here. You know we don't stand for the name calling here. Either back down or suffer the consequences.

 

[N_Jay]

Actually you know better than this! I guess the color choice had me miss it initially on my screen (my problem and fixed as of now). This is not the tavern and you know we will not stand for the bickering I see going on here. You know we don't stand for the name calling here. Either back down or suffer the consequences.

Sorry Lou,

I typically don't pay any attention to what forum I am in.

 

[ff-medic]

Guys, this isn't English 101. There are people who have poor grammar and there are people that make typos. The latter does not deserve grammar nazi remarks.

I guess some people here are perfect. And some people post, in order to start chaos, and a mudslinging exercise. Geeze.

People are not infallable,and are subject to make mistakes. Typos are typos. Pronouns,verbs, adjectives, prepositional phrases.......Who Cares?

This is a website based on hobby. Being social and interacting. Not having a masters, Phd, and being perfect in the ways of grammar and typing.

I agree with Wayne_H , This is not English 101.



10-32 ....................FF-Medic

 

[zerg901]

Does anyone have a URL for any document that says that digital has better range than analog? FCC, APCO, MRT, IEEE, Motorola, M/A-Comm, IAFF, IAFC, FEMA, DOHS, US Fire Admin, DOJ, SafeCom, NTIA, military, ARRL, etc? Any "officialish" website at all? Peter sz

 

[N_Jay]

Does anyone have a URL for any document that says that digital has better range than analog? FCC, APCO, MRT, IEEE, Motorola, M/A-Comm, IAFF, IAFC, FEMA, DOHS, US Fire Admin, DOJ, SafeCom, NTIA, military, ARRL, etc? Any "officialish" website at all? Peter sz

Asked and answered!!!

Start with TSB-88, then do the math!

You have to buy the document, but there has been plenty written about it.

http://electronics.ihs.com/document/abstract/GAJAGBAAAAAAAAAA

http://www.antd.nist.gov/wctg/manet/docs/TIAWG88_20.pdf

http://www.softwright.com/faq/engineering/tsb88faq.html

 

[zerg901]

None of those URLs lead to a document that says digital has better range than analog. Peter Sz

 

[N_Jay]

None of those URLs lead to a document that says digital has better range than analog. Peter Sz

Yes, you either need to learn it experientiality, or you need to understand the math in the links.

Since you seem to want a short cut, you will have to rely on people telling you.:wink:

 

[zerg901]

The math is simple calculus. None of the documents say that digital has better range. The documents just lay out the procedures for evaluating systems - I did not see any comparisons that had been actually conducted.

I am not trying to take any shortcuts.

I will ask again - does anyone (besides N Jay) have a URL leading to a official document that says digital has better range than analog?

I checked the FCC website. I found nothing that said digital has better range. In fact the descriptive / explanatory material on the FCC website doesn't even seem to mention P25.

Peter Sz

 

[N_Jay]

Go back to TSB-88B.

Determine what threshold you consider to be equivalent quality signal between analog FM (Typically at 12.5 kHz) and P25.
Compare the mean signal level required to provide that signal level at a given reliability for each modulation.

Read this: (Except it does not count since I posted it)

3.2 Channel Performance Criterion (CPC)
The CPC is the specified minimum design performance level in a faded channel. Its value
will be dependent upon ratios of the desired signal to that of the other distortion
mechanisms which exist within the service area. It will be defined as a minimum Rayleigh
faded carrier magnitude to the sum of all the appropriate static or faded distortion sources,
Cf/(SI+SN). This Faded Reference Sensitivity will require an absolute power reference, and
for digital systems an absolute value in terms of a delay spread performance factor which
addresses the decrease in sensitivity which occurs at some given delay spread parameter,
after which critical delay spread is achieved. This is provided via the Reference Sensitivity,
a static desired carrier-to-noise ratio, Cs/N, for bench testing which provides the absolute
power requirement for the Cs/N criterion, for example, 5% static BER at 55 ms delay
spread for a given digital modulation or 12 dB SINAD for analog frequency modulation.
The delay spread test is with standard input signal level. Table 5 of Appendix-A contains a
tabulation of common modulations for projected CPCs.
The Faded Reference Sensitivity may be for a lower CPC than specified by the User. The
appropriate design faded sensitivity for the required CPC shall be used. It will be based on
the required Cf/(SI+SN) for the signal quality baseline required for the particular radio
service.

 

[wolverine]

Digital is inevitable.

This Is true, I've already made the swith myself with my XTS3000 Uhf and XTS 5000 Vhf.
Now only If these ham repeaters (I probally go out and take the test If we got a P25 ham repeater up In the Cincinnati too Dayton area) can make the swith or better yet, some GMRS swith to Apco or Apco 25.

I do agree with other user post and I've been saying this for some time, I love digital Apco Motorola radio's (Untill you talk on one, your just not going to know what I'm talkin about), however just going over too Apco does not solve the problem of Interoperable and to best of my knowledge, In order to have Interoperable with other systems In different frequency bands (Uhf, Vhf, 800Mhz, etc.), every one's system would have to be patch Into each other's, I dont think we will ever see nationwide Interoperable, even If It's ever possible.