Blue Ridge Parkway - Changes ?

[dlwtrunked]

...
Back on BRP I got transmissions on 172.750 and 173.7625 today both confirmed BRP use via appropriate NAC.

Note that Shenandoah National Park use 173.7625 (NAC 4F9) with the repeater outside the park and on
Massanutten Mountain ("Big Mountain" near Newport, VA) ~38.60097N/078.63205W
It uses a data link on 417.5250 data back to Hogback Mountain.

 

[Ghstwolf62]

I'm getting 166.9 with that NAC but no other freqs off there.

The last hit recorded on Proscan on 7625 was an NAC of 150. 160 is listed in the DB for it. I imagine its BRP

750 is 150 as of last hit on it.

Their analog is still quite active on both 725 and 750.

 

[kb4cvn]

Everyone mentions ctcss tones and NAC's.

What talkgroups are you seeing used for the P25 comms?

 

[BigLebowski]

If talkgroups are coming across the BRP repeaters it is the default and/or inadvertently. The radios are not programmed that way.

 

[Ghstwolf62]

Mind you these are the last hit on the freq used only
166.9 is 65535 UID 740

750 and 7625 are TG 1
UIDs 1001 & 1002

Sometimes the TG changes with the user. Mobile might be TG 1 while Dispatch is 65535

 

[gesucks]

The change in TG is most likely due to difference in default programming of different brands of radios

 

[kb4cvn]

The default P-25 talkgroup if one is not intentionally programmed into a radio is GID-00001.

If the comms are encrypted, a talkgroup is required. Too often than not, whoever is programming the radio also programs the encrypted comms for GID-00001, thereby subjecting all the users with digital garbage (aka: R2D2 on LSD noise).

If an agency is smart, they program maintenance comms on one talkgroup, law enforcement on another, secure comms on yet another. Basically the P-25 version of a community repeater were users utilized different CTCSS tones to not 'hear' each other.

In this scenario, the maintenance folks could have their talkgroup to talk, and not scan to monitor the law enforcement crowd unless they wanted to. Less user fatigue, especially in high traffic systems.


My humble 2¢ worth....

 

[BigLebowski]

The default P-25 talkgroup if one is not intentionally programmed into a radio is GID-00001.

If the comms are encrypted, a talkgroup is required. Too often than not, whoever is programming the radio also programs the encrypted comms for GID-00001, thereby subjecting all the users with digital garbage (aka: R2D2 on LSD noise).

If an agency is smart, they program maintenance comms on one talkgroup, law enforcement on another, secure comms on yet another. Basically the P-25 version of a community repeater were users utilized different CTCSS tones to not 'hear' each other.

In this scenario, the maintenance folks could have their talkgroup to talk, and not scan to monitor the law enforcement crowd unless they wanted to. Less user fatigue, especially in high traffic systems.


My humble 2¢ worth....

1) Radios without encryption (either no UCM or not keyed) do not unmute for encrypted transmissions so that is a non issue.

2) Different talkgroups are a terrible idea. Users would be keying up on top of each other all the time and if someone needs to make an emergency call they do not have time to stop and wait to see if the channel busy LED is already flashing.

Again, the radios are not programmed to intentionally use talkgroups, I know this for a fact. Very, very few conventional P25 systems use talkgroups. I have used talkgroups before to filter out specific STARS talkgroups when conventionally monitoring with an XTL5000, and even then it doesn't work that great.

 

[gesucks]

"If the comms are encrypted, a talkgroup is required."

This statement is 100% not correct.

 

[kb4cvn]

"If the comms are encrypted, a talkgroup is required."

This statement is 100% not correct.

If you were to look at the P-25 data superframe of an encrypted transmission, there is a talkgroup present.

Every brand of radio I have ever dealt with professionally (Icom, Harris, Moto, EFJ, Thales, BK and Tait) all require a talkgroup to be designated with encrypted radio programming. It is part of the P-25 Standard.

Otherwise, how would the transmitting radio know what talkgroup to assign the encrypted transmission to?

 

[kb4cvn]

1) Radios without encryption (either no UCM or not keyed) do not unmute for encrypted transmissions so that is a non issue.

2) Different talkgroups are a terrible idea. Users would be keying up on top of each other all the time and if someone needs to make an emergency call they do not have time to stop and wait to see if the channel busy LED is already flashing.

Again, the radios are not programmed to intentionally use talkgroups, I know this for a fact. Very, very few conventional P25 systems use talkgroups. I have used talkgroups before to filter out specific STARS talkgroups when conventionally monitoring with an XTL5000, and even then it doesn't work that great.

Radios, if programmed correctly would not interfere with each other due to the BUSY TRANSMIT LOCKOUT function. If someone programs radios and disables this function.........is simply a fool. It is a safety function built into the protocol, and is enabled by default for a reason.

 

[Ghstwolf62]

Picked up TG 4095 on 725 last night and again tonight.

 

[BigLebowski]

Radios, if programmed correctly would not interfere with each other due to the BUSY TRANSMIT LOCKOUT function. If someone programs radios and disables this function.........is simply a fool. It is a safety function built into the protocol, and is enabled by default for a reason.

This is also not true. Please don't spread misinformation.

Back to the topic at hand though, since the outage the Parkway is back to normal operations as far as I can tell. I traveled the Boone-Floyd segment the other day and was in the Roanoke area a couple weeks ago. Operations as normal.

 

[kb4cvn]

This is also not true. Please don't spread misinformation.

With all due respect, I worked for 34 years in two-way radio, retiring from Harris Corp in Lynchburg in 2012.

I was the lead Tech Support Engineer at the factory (in TAC) supporting mobiles, portables and encryption systems for over 11 years, before being promoted to System Engineering, were from 2008 until 2012 I designed and installed new P-25 trunked radio systems for the US Government.

I know what I am talking about, as I designed a good bit of it, and implemented it on a daily basis!

After retiring from Harris, I worked as a contract consultant for Harris and others until January of this year.

You are welcome to view my experience on my company webpage: Background or on LinkedIn: https://www.linkedin.com/in/mark-cobbeldick-8bb93933/

 

[Ghstwolf62]

This is also not true. Please don't spread misinformation.

Back to the topic at hand though, since the outage the Parkway is back to normal operations as far as I can tell. I traveled the Boone-Floyd segment the other day and was in the Roanoke area a couple weeks ago. Operations as normal.

Well since Mark spent a million years working for GE/Harris programming and installing systems and radios for a multitude of thing including numerous PS agencies I would be cautious in accusing him of not knowing what he's talking about or spreading disinformation not to mention lying.

Even my DMR radios has the ability which you've called not true and disinformation to not transmit if the freq is in use by anybody else even if they are on another talk group.

I'd say you're misinformed if anybody. If a DMR radio has it I'd be completely shocked to find out a commercial grade PS radio does not.

 

[Ghstwolf62]

Back on topic I've been hearing them call in on the "Roanoke Mountain" repeater lately. Not sure where that is and its not listed in the DB.

 

[BigLebowski]

With all due respect, I worked for 34 years in two-way radio, retiring from Harris Corp in Lynchburg in 2012.

I was the lead Tech Support Engineer at the factory (in TAC) supporting mobiles, portables and encryption systems for over 11 years, before being promoted to System Engineering, were from 2008 until 2012 I designed and installed new P-25 trunked radio systems for the US Government.

I know what I am talking about, as I designed a good bit of it, and implemented it on a daily basis!

After retiring from Harris, I worked as a contract consultant for Harris and others until January of this year.

You are welcome to view my experience on my company webpage: Background or on LinkedIn: https://www.linkedin.com/in/mark-cobbeldick-8bb93933/

And with all due respect given... your suggestion that public safety operations share what amounts to a community repeater with other non-public safety operations (maintenance) shows your lack of experience with public safety operations.

I'm not questioning your two-way radio experience as i'm sure it's extensive.

 

[kb4cvn]

The Blue Ridge Parkway has non-standard communications needs.
Which therefore requires a unique communications system solution.

They are mixing Law Enforcement (LE) Operations and Maintenance Operations over the same frequency now, and have for decades. The only difference today is the addition of Project-25 [digital] format communications. It works for them...
They do what they do because of years of experience and trial-and-error, having found a solution that works for them.

BTW:
In my background is public safety communications, maintaining radios on a day-to-day basis, management of both conventional and trunked radio systems for First Responders, and as the Manager of a 9-1-1 Communications System (and call center). I was recruited by the factory in Lynchburg because of my heavy public safety background.

 

[tglendye]

And with all due respect given... your suggestion that public safety operations share what amounts to a community repeater with other non-public safety operations (maintenance) shows your lack of experience with public safety operations...

Does SNP not do exactly this? I believe they do.

The Blue Ridge Parkway has non-standard communications needs.
Which therefore requires a unique communications system solution.

They are mixing Law Enforcement (LE) Operations and Maintenance Operations over the same frequency now, and have for decades. The only difference today is the addition of Project-25 [digital] format communications. It works for them...
They do what they do because of years of experience and trial-and-error, having found a solution that works for them.

BTW:
In my background is public safety communications, maintaining radios on a day-to-day basis, management of both conventional and trunked radio systems for First Responders, and as the Manager of a 9-1-1 Communications System (and call center). I was recruited by the factory in Lynchburg because of my heavy public safety background.

And without your helpfulness and experience, certain parts in the database would lacking. I know one area in particular where we would still be trying to discover information.

 

[Ghstwolf62]

And with all due respect given... your suggestion that public safety operations share what amounts to a community repeater with other non-public safety operations (maintenance) shows your lack of experience with public safety operations.

I'm not questioning your two-way radio experience as i'm sure it's extensive.

And apparently you know very little about much of anything.

Public safety systems across the country share their system with everything from school buses to garbage trucks along with police and fire.

The parks etc out here have everything on their channels. I listen all the time to calls about toilets stopped up, and light switches going out to ill people and drunks causing problems and all on the same system.