Tetra interference

[kayn1n32008]

Okay - i stand corrected i guess
I was under the impression that "DMR" was kind of a blanket term for any of these non-P25 digital voice formats such as Nexedge,MotoTrbo,etc.

DMR is actually an ETSI published standard named Digital Mobile Radio. Motorola's trade name for it it MotoTRBO. Every other company out there that builds DMR radios, calls it DMR.

Ironically Kenwood does offer DMR compliant radios in Europe, and soon/now in North America.

Kenwood and Icom came up with NXDN, Kenwood trade named it Nexedge and Icom trade name for NXDN is IDAS.



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[Darkstar350]

DMR is actually an ETSI published standard named Digital Mobile Radio. Motorola's trade name for it it MotoTRBO. Every other company out there that builds DMR radios, calls it DMR.

Ironically Kenwood does offer DMR compliant radios in Europe, and soon/now in North America.

Kenwood and Icom came up with NXDN, Kenwood trade named it Nexedge and Icom trade name for NXDN is IDAS.



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Interesting...

Just a bit more on those buses that operate on that 470mhz LTR system - there are several bus talkgroups - but they are apparently all the same agency
However - the reason behind the multiple talkgroups is they have it set up so that a single talkgroup is actually a single unit/bus/car,etc calling dispatch - and vice versa
So for example - lets say TG 00-01-01 is "unit one" and TG 00-01-02 is "unit 2" - they are both part of the same agency but you will only hear dispatch and "unit one" communicating back and forth on talkgroup 00-01-01, and only "unit 2" calling dispatch/dispatch calling unit 2 on TG 00-01-02
And so on and so forth

I am not sure if that is the "Metro comm" setup that was mentioned but it sounds similar to me the way i am interpreting it(more than one agency actually uses that setup on this system and i am in the process of confirming several more talkgroups)...

 

[kayn1n32008]

Interesting...



Just a bit more on those buses that operate on that 470mhz LTR system - there are several bus talkgroups - but they are apparently all the same agency

However - the reason behind the multiple talkgroups is they have it set up so that a single talkgroup is actually a single unit/bus/car,etc calling dispatch - and vice versa

So for example - lets say TG 00-01-01 is "unit one" and TG 00-01-02 is "unit 2" - they are both part of the same agency but you will only hear dispatch and "unit one" communicating back and forth on talkgroup 00-01-01, and only "unit 2" calling dispatch/dispatch calling unit 2 on TG 00-01-02

And so on and so forth



I am not sure if that is the "Metro comm" setup that was mentioned but it sounds similar to me the way i am interpreting it(more than one agency actually uses that setup on this system and i am in the process of confirming several more talkgroups)...

Likely the bus/car/units all receive the dispatch talkgroup(00-01-001) and transmit on separate talkgroups (bus 1 Tx TG 00-01-002, bus 2 Tx TG 00-01-002 ect. I have heard of that type of set up for taxi services so every unit hears dispatch, but does not hear individual cars.

 

[radioman2001]

Actually the Atlantic bus system is owned by Atlantic Bus Company. Rumors has it as a broken nose boys operation. I had dealings with them back in 90's when Westchester Para-transit bidded out operations and broke the contract into 3 pieces. I think they were White Plains Bus, Atlantic and some company owned by Chrysler Corp financial. I provided radios for Atlantic and Chrysler, then Chrysler went belly up in less than a year, because they said the ROI was too low in the NYC area, and Atlantic said my charges were too high so they then built their own first system on the of all places the Chrysler building.

With LTR you do have capability of calling individual units since there are 254 groups per home channel. So if you have a 5 channel LTR you can call individually 5 times 254 units. One of 470 mhz Atlantic frequencies was originally mine until my contract with the owners expired and they sold it to Atlantic.(BTW not legal)

METRO-COMM is nothing like LTR as METRO-COMM has a data only channel similar to trunking, and there can be multiple voice channels. Plus the bus operator hears nothing unless called or make a request to transmit which can be held in que, again similar to Moto type I trunking.

 

[Darkstar350]

Likely the bus/car/units all receive the dispatch talkgroup(00-01-001) and transmit on separate talkgroups (bus 1 Tx TG 00-01-002, bus 2 Tx TG 00-01-002 ect. I have heard of that type of set up for taxi services so every unit hears dispatch, but does not hear individual cars.

Some of the users on this system do have a setup where it is simply a dispatch talkgroup , and the rest of the talkgroups are just mobile to dispatch (Example: 0-01-001 is the dispatch side of the convo. and 01-01-002/ 01-01-003 are calling dispatch...)
The buses along with a few other users have a different setup then that
In other words - there is a different talkgroup for every single bus however one can hear both the dispatch and the mobile side of the conversation on said talkgroup - if that makes sense...
It is a unusual setup indeed - think of it as somewhat a private call for each talkgroup
What i dont know is if every bus can hear dispatch at the same time - or only whatever bus that dispatch calls on the dedicated talkgroup...
As far as what company these buses are - i have no idea but i have heard of Atlantic Transportation however this system is owned by "Atlantic Telecommunications" which is a private carrier radio company who leases radios to various businesses
No clue if there is a link between Atlantic Bus co./Atlantic Telecom...

I just realized that i may have some confusion in regards to this MTA/Tetra ordeal -

The first post of this thread stated that "the MTA plans to switch its bus radio system to Tetra"
Then there were references made that this Tetra system will therefore replace a outdated yet currently in use 800mhz radio system

There is a 800mhz transit system in use the New York City Transit authority -
New York City Transit Authority Trunking System, New York, New York - Scanner Frequencies

as well as a 900mhz system in use by the Metropolitan Transit Authority -
MTA Regional Bus Trunking System, New York, New York - Scanner Frequencies

So to clarify - will this supposed Tetra system be replacing the NYCTA 800mhz system?
Or is this in regard to the MTA 900mhz system?...

 

[radioman2001]

There is no Public Safety Band allocation on 900 mhz it is all SMR business, so based on the information about their testing in the past, and the article mentioned I would say the 800 mhz bus system. BTW the 900 mhz originally belonged to Queens Transit and I believe SI Rapid Transit (and a few others) a private company that went broke in the early 90's, NYC TA then bought what was left of their assets.

With LTR you can program groups to RX inclusive or exclusive. EG: RX 001, 020 to 030 and not any other, but you can only TX on one group per channel.

"No clue if there is a link between Atlantic Bus co./Atlantic Telecom."

One and the same, as I said in previous post they started that company as a result of the cost associated of their radios systems. The first system they built was a 900 on the Chrysler building in the mid 90's since then they have been grabbing up any channel they can get that's clear on 470 mhz.

 

[Darkstar350]

There is no Public Safety Band allocation on 900 mhz it is all SMR business, so based on the information about their testing in the past, and the article mentioned I would say the 800 mhz bus system. BTW the 900 mhz originally belonged to Queens Transit and I believe SI Rapid Transit (and a few others) a private company that went broke in the early 90's, NYC TA then bought what was left of their assets.

With LTR you can program groups to RX inclusive or exclusive. EG: RX 001, 020 to 030 and not any other, but you can only TX on one group per channel.

"No clue if there is a link between Atlantic Bus co./Atlantic Telecom."

One and the same, as I said in previous post they started that company as a result of the cost associated of their radios systems. The first system they built was a 900 on the Chrysler building in the mid 90's since then they have been grabbing up any channel they can get that's clear on 470 mhz.

Thanks for the info - this is all starting to make sense

Yeah i am thinking that this Tetra proposal is probobly in regard to the 800mhz system
But now i wonder if they are considering replacing both 800 and 900mhz systems

Either way being that NYC's new 700mhz Phase 2 system is now on the air - considering another 700mhz system in such close proximity does leave room for interference

I pick up the NYC 800mhz system that the sewer dept. is on so-so - it really dosent seem like it has the greatest of coverage probobly due to all the noise floor on 800mhz in NYC and the surrounding areas - so with 2 700mhz systems in NYC going at the same time i can see a similar situation...

We shall see...

 

[car5le]

Already Problems...

Motorola Solutions files protest against New York City transit award of 700 MHz TETRA radio system | TETRA content from Urgent Communications

 

[JimTheScot989]

Tetra & NYC TA

Thanks for the info - this is all starting to make sense

Yeah i am thinking that this Tetra proposal is probobly in regard to the 800mhz system
But now i wonder if they are considering replacing both 800 and 900mhz systems

Either way being that NYC's new 700mhz Phase 2 system is now on the air - considering another 700mhz system in such close proximity does leave room for interference

I pick up the NYC 800mhz system that the sewer dept. is on so-so - it really dosent seem like it has the greatest of coverage probobly due to all the noise floor on 800mhz in NYC and the surrounding areas - so with 2 700mhz systems in NYC going at the same time i can see a similar situation...

We shall see...

.....
Please read the NYC TA RFP. It is available online, do a Google Search for it. It will clear most of the mentioned discrepancies and misinformation on this forum.

Tetra is NOT a strictly European radio protocol. It is used in Many countries, it is mostly a mission critical radio system (public safety) but is used for other services. It is NOT a short range radio system. std settings provide for 36 mile range from base station, optional Air-ground offers 51 mile range from base station. It is NOT a low power radio system, it has 1 Watt, 1.8 Watt, 3 Watt portables (one mfr had 5 W portables), and 5 W, 10 W, 35 W and 45 W mobiles, base stations range up to 75 W, depending on manufacturer. BTW, there are about 9 Tetra manufacturers in the World! Much better competition than the P-25 situation.. The interference issue is contrived bad propaganda. Please read the Tetra spec and the numerous arguments over NJ Transit Tetra. Tetra emission envelope is cleaner and tighter than any ole USA modulation scheme. So much so that Tetra can adjacent channel at co-site applications. Try that with P-25!

And for those dedicated and interested persons and radio men who have heart palpitations over their favorite radio manufacturer, PLEASE take your heart medications & sit down before you research the international radio market for Tetra manufacturers and what they support! And for the bad propaganda against Tetra, one may be severely dismayed at the level of misguidance perpetrated on you.
As one USA radio manufacturer sales team is known to say "Its not personal, Its business!"

Cheers!

 

[JimTheScot989]

OK get ready, sit down, relax. This was just announced today, Mar 17, 2016: "Motorola Solutions acknowledges it proposed 700 MHz Tetra system for NYC transit before filing protest".....
<urgentcomm.com/tetra/motorola-solutions-acknowledges-it-proposed-700-mhz-tetra>

BTW, the NY Daily News article is so in error and misleading!

Cheers!

 

[radioman2001]

Nothing new about Moto, complaining, every time they lose in NYC they complain and in some cases sue. In the late 70's NYCTA released a bid for a complete replacement of the Subway Radio System. (I think Moto was bidding a trunked 800) The company I worked for (Fischbac and Moore) won the bid and then 3 times it was rebid because Moto sued. Finally the Judge who was at this point very upset with NYCTA and Moto said you have to accept the bid, you can't keep throwing out the bid and rebid because you don't like the vendor. NYCTA then issued a change order on the whole bid for a one for one replacement only of all the equipment with some replacement and new installation of radiating cable.

BTW NYCTA has been going away from Mother M for years. The system I helped put in during the mid 80's was GE, they have bought thousands of Bendix/King portables. Plus NYPD has bought Vertex because Moto wouldn't give they what they wanted in a new portable. That's a whole other subject and there is lots of info on this board about it.

The moral of the story is even if you are Moto, don't piss off the largest Police force in the U.S. when it comes to what they want and not what is on the sales mans plate for the week to sell.

JimTheScot989 is right, Tetra is an International protocol and is used all over the world and it works. Most systems are base heavy more akin to cellular and it doesn't have to be encrypted, but if I know NYC they will.

The Moto responce of proposing a 700 Tetra is the smack up the side of their head attention they finally realized, and it shows how desperate Moto is getting. I also could not find that proposal on Urgent I think the link is broken.

 

[JimTheScot989]

NYC TA Tetra

Urgent comms sometimes doesn't work...

Moto admitts offered tetra: = <http://urgentcomm.com/tetra/motorola-solutions-acknowledges-it-proposed-700-mhz-tetra-system-nyc-transit-filing-protest?NL=UC-03&Issue=UC-03_20160317_UC-03_507&sfvc4enews=42&cl=article_3_b&utm_rid=CPEQW000001076275&utm_campaign=7041&utm_medium=email&elq2=668c8b7b1f714a65a40cf39df86b4664>

The above link mess does work on three different browsers..

 

[KevinC]

Urgent comms sometimes doesn't work...

Moto admitts offered tetra: = <http://urgentcomm.com/tetra/motorola-solutions-acknowledges-it-proposed-700-mhz-tetra-system-nyc-transit-filing-protest?NL=UC-03&Issue=UC-03_20160317_UC-03_507&sfvc4enews=42&cl=article_3_b&utm_rid=CPEQW000001076275&utm_campaign=7041&utm_medium=email&elq2=668c8b7b1f714a65a40cf39df86b4664>

The above link mess does work on three different browsers..

Woks fine for me using Chrome.

 

[radioman2001]

Gotta love mother M proposing a non-existant radio in an attempt to get a bid.

Mother M: "Well Mr NYC MTA you see we have a radio for you that's not type accepted, BUT if you accept our bid we will build you a newer one that might be, and we will find out then if it's legal"

As I have been saying for quite awhile M doesn't want TETRA in the U.S. because it's a vendor neutral system, all products MUST conform to a standard unlike P-25 Phase I and II.

I wish NYC the best on this build out, they put the time and effort to look it over, and built a test system that they ran for over a year to prove it's capability. I wish I had some more work time left before I retire, the FCC techs they are hiring are getting about $125K a year and don't even have to do the work, they just watch over the vendor.

BTW I just saw this morning that EF Johnson which was bought by Kenwood is now branding their P25 line under the Kenwood name.

 

[jim202]

Nothing says you have to make a 700 MHz system P25. Only the interop channels "have to" be P25, and in the age of software defined radios, that's just another waveform. Aside from that, TETRA, OpenSky, DMR, is all potentially acceptable if Region 8 approves the submission. The submission is analyzed more on how the signal is contained within the defined area that needs to be covered, and not necessarily on the protocol used.

Who says the normal interop channels have to be P25? Please provide where your getting that information from.

All the information posted on the Internet including the NIFOG from DHS indicated they are all analog.

 

[Thunderknight]

Who says the normal interop channels have to be P25? Please provide where your getting that information from.

All the information posted on the Internet including the NIFOG from DHS indicated they are all analog.

They do in 700 MHZ only. 47 CFR 90.548.