Worcester Radio Systems Issues Continue

[maus92]

I was on the lower shore yesterday and ran Unitrunker for about an hour. The system *seems* to be assigning selected public safety TGs to FDMA channels, while others remain TDMA. I'll have to look at the data more closely, but there definitely was FDMA in use.

 

[DisasterGuy]

Can to clarify / expand on what you mean by "real life" specs?

I'm not sure exactly what he means however every system put to bid that I am aware of in the region (excluding the State of MD system) was specified, designed and implemented with a 95/95/95 standard. Building loss is surveyed to determine a maximum attenuation level for 95% of buildings. The system then provides coverage to that level in 95% of the service area with 95% reliability.

 

[ThePhotoGuy]

I was on the lower shore yesterday and ran Unitrunker for about an hour. The system *seems* to be assigning selected public safety TGs to FDMA channels, while others remain TDMA. I'll have to look at the data more closely, but there definitely was FDMA in use.

I was in Ocean City the past week. Where I stayed, I was able to monitor Ocean Pines, Ocean City, and Worcester Sites all at the same time.

From what I saw, for a majority of the time most of the local Police (Pocomoke, Ocean Pines, Berlin, etc.) were in FDMA on the Worcester Site. While they were in FDMA on the Worcester at times, those talkgorups that were also active on Ocean Pines and Ocean City sites were operating in Phase II. Sometimes the Sheriff was also in FDMA on the Worcester Site. I also did notice at least once some of the Ocean City Police talkgroups in Phase I on the Ocean Pines and Worcester sites but not on the Ocean City Sites. I did see Worcester Fire 4 in Phase I sometimes but didn't seem as common as the Police talkgroups in Phase I.

Very rarely did I ever see any FDMA activity on the Ocean City Site.

 

[DisasterGuy]

All voice traffic on Ocean Pines and Ocean City runs TDMA. Most voice traffic on Worcester is currently being brought down to FDMA. The entire multi-region system is designed to operate dual dynamic mode allowing a transmission to be operating in different modes at different sites.

 

[ResQguy]

with law suits and transparency being so rampant. the ablitity to have a recorded account of the event is parimount. Not gonna happen with talk around, in building use.. Build the system to REAL LIFE specs and the rest will take care of itself

FDNY records all their simplex fireground traffic using a custom built Tactical Communications Recording System in their command vehicles.

 

[ocguard]

with law suits and transparency being so rampant. the ablitity to have a recorded account of the event is parimount. Not gonna happen with talk around, in building use.. Build the system to REAL LIFE specs and the rest will take care of itself

Here's the problem. Not one single system can guarantee 100% in-building coverage. I'm sure there'll be no argument there. And when we find buildings (or even outdoor locations) where coverage doesn't support mission-critical radio network coverage, it's almost always too late to make a contingency. And, with the nature of trunking, there is no "seemless" fallback/transition to simplex that keeps all users "in the loop" like with conventional repeater/talk-around did.

So, unless a "building to real-life specs" includes mobile extenders in every vehicle (which is honestly completely reasonable), there needs to be an EASY and QUICK simplex option. In some circumstances, that means defaulting to simplex during interior fireground operations. I would argue that if a department chooses to go this route, their apparatus need to be equipped with on-scene receiver/recorder devices to reasonably capture on-scene simplex comms. But I guess the, the argument could be made to just make it a vehicle repeater too.

 

[maus92]

Here's the problem. Not one single system can guarantee 100% in-building coverage. I'm sure there'll be no argument there. And when we find buildings (or even outdoor locations) where coverage doesn't support mission-critical radio network coverage, it's almost always too late to make a contingency. And, with the nature of trunking, there is no "seemless" fallback/transition to simplex that keeps all users "in the loop" like with conventional repeater/talk-around did.

So, unless a "building to real-life specs" includes mobile extenders in every vehicle (which is honestly completely reasonable), there needs to be an EASY and QUICK simplex option. In some circumstances, that means defaulting to simplex during interior fireground operations. I would argue that if a department chooses to go this route, their apparatus need to be equipped with on-scene receiver/recorder devices to reasonably capture on-scene simplex comms. But I guess the, the argument could be made to just make it a vehicle repeater too.

Personally, I think they should go with a DVRS solution, starting with first due units and/or command units - it is functionally/operationally similar to a simplex/talkaround solution, yet also leverages the advantages of a TRS. Maybe they have a few spare VHF freqs lying about, or could get some 700 LP pairs to support it. And it seems to me that outfitting a modest number of apparatus that are first due in problem areas (like seemingly Ocean Pines) would be cheaper than building new tower sites. And constantly train and refresh personnel how to use their radios.

 

[riveter]

This is off the rails, but just from an experienced service perspective, I'd caution that mobile vehicle extenders and PARTICULARLY DVRS units are extremely high-maintenance and prone to failure.

 

[maus92]

This is off the rails, but just from an experienced service perspective, I'd caution that mobile vehicle extenders and PARTICULARLY DVRS units are extremely high-maintenance and prone to failure.

Interesting. Allegany County is relying on DVRS to give them in-building coverage on the FIRST system - both on the fire side and their sheriffs. I wonder what their experience has been thus far.

 

[dcr_inc]

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[ResQguy]

This is off the rails, but just from an experienced service perspective, I'd caution that mobile vehicle extenders and PARTICULARLY DVRS units are extremely high-maintenance and prone to failure.

Many large fire and police departments with hundreds of DVRS units not experiencing failures would look cross-eyed at this post.

 

[riveter]

Many large fire and police departments with hundreds of DVRS units not experiencing failures would look cross-eyed at this post.

Fair enough, I suppose there are some out there. I sank a few months of my life into doing constant repair of them across similarly large departments that could never get a working rate of more than 20%.

 

[CavmnLwyr]

The City of Kansas City FD deployed 130 repeaters in the field. They were configuring them for three years, used them for a few, then stopped using them altogether unless there was a coverage issue. In one particular case, they had a large percentage of their firefighters in the fireground that were not receiving messages.

 

[boatbod]

There is a thing called simplex for in building fire operations. Why people insist on using TRS or any repeated system for interior work is beyond me. You'll never guarantee interior coverage and there could possibly be system busy outs on a large scale incident.

Stupid, just stupid.

The problem with simplex use on the fireground is that your dispatch center likely cannot monitor it, and if for some reason Command doesn't hear the interior crew, it's quite likely nobody else can either. At least with a TRS you *know* when you're not hitting the tower because you get boinked. If you get a confirmation tone, at least someone can hear you and relay to other fireground units.

 

[firebal]

Many jurisdictions in the Washington / Baltimore region use TGs on their TRS's for tactical / in building comms. Montgomery, Anne Arundel, Allegany and I suspect others sometimes use DVRS on their vehicles to bridge between their handhelds and the TRS. Additionally, building codes call for BDAs to be installed in larger / critical building to improve service - but you cannot expect them in residential structures.

I have yet to seen BCoFD use these, as a new volunteer in the county I would hope that they at least consider them.

 

[12dbsinad]

The problem with simplex use on the fireground is that your dispatch center likely cannot monitor it, and if for some reason Command doesn't hear the interior crew, it's quite likely nobody else can either. At least with a TRS you *know* when you're not hitting the tower because you get boinked. If you get a confirmation tone, at least someone can hear you and relay to other fireground units.

Why wouldn't anyone else hear the interior crew if command does not? This has never proven to be the case as I have never been aware of a LODD due to failed simplex communications. Someone WILL likely hear them and relay, that's one of the key benefits of it. Look at the flip side of the LODD's that cited use of TRS and the failures associated. Also, just because you don't get bonked doesn't mean you're going to send a reliable transmission that's understood. You also have the problem with site affiliation issues with a concentrated scene, exp with these whackers with affiliated Flea bay radio's

 

[maus92]

Why wouldn't anyone else hear the interior crew if command does not? This has never proven to be the case as I have never been aware of a LODD due to failed simplex communications. Someone WILL likely hear them and relay, that's one of the key benefits of it. Look at the flip side of the LODD's that cited use of TRS and the failures associated. Also, just because you don't get bonked doesn't mean you're going to send a reliable transmission that's understood. You also have the problem with site affiliation issues with a concentrated scene, exp with these whackers with affiliated Flea bay radio's

VRS can operate in a simplex mode.