Batboard

Hello!

While surfing on the net I found a quite interesting link:
http://www.tele-com.poznan.pl/Report_EN.pdf

They have compared P25, TETRA and analog systems in the real world, and in a nearly identical terrain configuration.

Too bad Tetra is useful in high density areas such as very large metro locations and can serve hundreds to thousands of users do to the design of the TDMA network which is mixed with the trunking architcture, not to mention a Tetra radio costs about 1/4 less than a comparable P25 radio.

The drawbacks with Tetra is the amount of sites needed to fill in major dead spots that a Tetra system can't handle as well as P25 systems.

P25 systems are higher power 'base' radios where as Tetra is of a much lower power and was never designed to cover the territory of N.A, to cover the areas that P25 stations cover, you can add probably close to 50 more sites above a P25 system, and still have the gaps that P25 usually fills quite well.

It's density over coverage, and this is where P25 comes out the winner, it gets the signals where they are needed by remote locations like a huge national forest, or sprawling urban/suburban areas that span 30+ miles.

Tetra can't meet as many of the requirements like P25 can.
P25 also has the same coverage overlay as an analog system it was designed to replace, usually mitigating the need for a complete system redesign, which lowers overhead cost to the taxpayer.

Tetra is popular in Europe as most cities are quite dense and are not spread out like here in the U.S.

Throw a lot more power into the mix, and TETRA will kick ass.

It's all academic. P25 is the agreed to standard for the most powerful and best country in the universe---the USA. UhRaw!!

Until we confirm the presence or lack of other life in the universe I don't think we can claim the most powerful and best damn country title just yet.

At least beyond this planet!



There's probably some dude with 5 heads reading this right now on altair 3 laghing his ass off...

Should we ever find out that there IS life on some other (loser) planet, or in another Universe, I recommend that the US (representing all that is good on planet Earth) launch a pre-emptive, all out, massive, no-holds-barred, thermo nuclear strike. UhRaw!!!!!!!!

and R. Lee should be our next president

We could always send the French.....


TETRA needs to stay in the market it was designed for, EUROPE.

Cheney 2008!

P25----Good for US
TETRA----Good for them

Chaney/Bush----Good for nothing!

Vote LIBERTARIAN and get the CORRUPT OUT of government.

I'll vote for Wayne Lapierre for prez.

*soapbox has now been dismantled*

P25---GREAT for the World!

The US is the leader of the world---"You're either with us, or you're against us," as President George W. Bush so wisely and brilliantly stated shortly after 9/11.

Cheney 2008! (and NOT McCain---he's as bad as Hillary!)

Yes, I agree: Wayne LaPierre for VP 2008!

Republicans have gigantic bank accounts; Libertarians are poor. Easy choice...

ASTROMODAT wrote:P25---GREAT for the World!

I really would wish P25 would have become spread over europe. It allows slow migration by being able to operate analog, the range is similar to plain FM, and in fact it is just changing modulation from FSK to FSK, being able to serve both simple conventional systems and large trunked networks. Tetra and Tetrapol may be more fancy viewing just the technology, but not in interoperability and interfaces :-(

FM to P25 involves FM modulation changing to FDMA (Phase I). Phase II will be TDMA. You mentioned FSK...

ASTROMODAT wrote:FM to P25 involves FM modulation changing to FDMA (Phase I). Phase II will be TDMA. You mentioned FSK...

You are mixing up modulation and access scheme. P25 is FSK modulation (4fsk), or qpsk as second possible mode, FDMA is both the access scheme for FM and P25, also for Tetrapol, while Tetra25 and GSM use TDMA.