What is the advantage of P25 over analog?

[RFI-EMI-GUY]

That it is P-25 that’s the advantage. No it’s the better sounding audio and security of Encryption

When Securenet DES was introduced I thought it sounded pretty bad with its CVSD "vocoder". But recently I compared some Systems Saber radios with an Astro Saber to get a feel for CVSD vs IMBE. Guess which one sounded more natural and had virtually no latency? CVSD!

Of course this was in simplex mode, not a "Reagan Era" Securenet Smartnet Simulcast with FRED boards.

 

[MTS2000des]

I have a ton of DES-XL boards for MTS2000s if you want them. And a stack of MSF5000 800s for "Maximum Station Flexibility" come and get em.

 

[mmckenna]

"Maximum Station Flexibility"

Huh. And all this time I thought MSF stood for "Might Stay on Frequency" (but unlikely).

 

[RFI-EMI-GUY]

I have a ton of DES-XL boards for MTS2000s if you want them. And a stack of MSF5000 800s for "Maximum Station Flexibility" come and get em.

I might just take you up on that!

 

[RFI-EMI-GUY]

Huh. And all this time I thought MSF stood for "Might Stay on Frequency" (but unlikely).

MSF = Might Stick on Floor. Those suckers are not worth the shipping weight. I knew of a tech who blew out a knee moving a 900 MHz PURC station up a stairwell.

 

[mmckenna]

MSF = Might Stick on Floor. Those suckers are not worth the shipping weight. I knew of a tech who blew out a knee moving a 900 MHz PURC station up a stairwell.

I straight up celebrated when those POS's went out the door. They were still running, but by God they wandered around the band like a drunken monkey. Towards the end they were retuned about every 2 months.

 

[magic_lantern]

Some of my observations, Dispatchers, Public Safety Telecommunicators or what ever they are called in your area are NOT radio operators therefore they dont understand radio communications. If a radio operator was communicating with someone with a weak signal they would know enough to lower the squelch to hear the other station, P25 does not have that ability, P25 audio quality is what ever it is when it comes out of the speaker.
P25 audio also is "what goes in is what comes out" when you have a dispatcher with a low voice, a girly voice, a timid kind of voice, someone who speaks fast and blends words or some kind of accent when that audio is converted back to analog to the speaker and it sounds crappy and unintelligible in many cases. I use an APX6000 on the system I use so its a legit radio and I cant tell you how many times I have said to myself "WTF did she just say" so I raise the volume to hear her and than when a loud voice comes out it scares the s&%# out of me cause I left the volume up.
bottom line is that there was nothing at all bad with analog and nothing at all wrong with conventional two way radio. I think alot of the scanner people want to hear comms that are far outside their geographic ability to monitor and like statewide systems so they can hear a fire call 150 miles away as if its going to affect them somehow.

 

[bearcatrp]

Nice thing about P25 is I can be 80 plus miles away from my home and still listen to P25 in my home area provided there is a P25 tower in my area. When I camp away from home but in my state, I can scan my local home area and listen.

 

[RFI-EMI-GUY]

Some of my observations, Dispatchers, Public Safety Telecommunicators or what ever they are called in your area are NOT radio operators therefore they dont understand radio communications. If a radio operator was communicating with someone with a weak signal they would know enough to lower the squelch to hear the other station, P25 does not have that ability, P25 audio quality is what ever it is when it comes out of the speaker.
P25 audio also is "what goes in is what comes out" when you have a dispatcher with a low voice, a girly voice, a timid kind of voice, someone who speaks fast and blends words or some kind of accent when that audio is converted back to analog to the speaker and it sounds crappy and unintelligible in many cases. I use an APX6000 on the system I use so its a legit radio and I cant tell you how many times I have said to myself "WTF did she just say" so I raise the volume to hear her and than when a loud voice comes out it scares the s&%# out of me cause I left the volume up.
bottom line is that there was nothing at all bad with analog and nothing at all wrong with conventional two way radio. I think alot of the scanner people want to hear comms that are far outside their geographic ability to monitor and like statewide systems so they can hear a fire call 150 miles away as if its going to affect them somehow.

How true. Getting an APX6000 is not going to fix my major beef with P25 through my BCD536HP scanner. Sometimes the audio sounds as good as analog. But for the most part, the dispatchers sound exactly like you describe.

 

[KC3ECJ]

P25 digital mode helps to eliminate noise and static and fading therefore providing a much cleaner clearer audio being easier to understand.

I disagree with that. On digital voices in general sound bad to me and higher pitched voices do worse.

 

[GMB951]

Va has P25 conventional and i hear them sometimes very clear here in Fayetteville,NC i enjoy hearing them this far away so the signals do reach out

 

[mmckenna]

A lot of the audio issues that people complain of with digital is due to poor radio setup.
Unfortunately it doesn't take any prerequisites to be a "radio programmer". Anyone that can download software off the internet is suddenly an expert.

It takes some skill and knowledge to set up the radios correctly. Most radio manufacturers in this arena will have some good documentation on setting radios up for optimum audio. I spent quite a bit of time setting ours up, using documentation from the manufacturer and our own testing. Side by side (same dispatcher, same radio console, same radios, same speakers), the digital sounds better.

Problem I often see is some random guy downloads CPS off the internets and watches a few Youtube videos. Boom, instant "expert".

 

[MTS2000des]

It takes skill set and expertise beyond the scope of most shadetree YouTube "teknishuns" to properly configure advanced P25 subscriber radios such as the APX or Harris XL platform. This is why vendors give week long in person training. Even then it takes a combination of experience and listening to one's user's to build templates and codeplugs out with optimized audio profiles for both RX and TX.

Many times deployments are done poorly without this training and/or subscriber programming is farmed out to the local shop who use default settings for audio and it doesn't sound as good as it could be if setup by someone who knows what they're doing.

I prefer my P25 audio over the static, crackling and popping of analog and my users enjoy consistent performance throughout the coverage area, and no loss of audio quality on encrypted talk groups.

 

[delaware74b]

True, the advantage of the P25 system is huge, especially with multiple agencies and mutual aid. For example Delaware fire service had 4 county fire channels for its 3 counties. The primary was 33.78 for all stations except Dover and Wilmington as they had their own channels. A working fire in Kent County often blocked out transmissions and tone-outs except in extreme northern New Castle and southern Sussex counties. Also, Sussex County often blocked out Kent on their tone-outs.

Now, each county has its own primary channel with each station having its own 'company channel'. There are mutual aid channels that law enforcement and fire share although a lot of the LEA are encrypted. One advantage to Delaware's setup is if you can use a scanner on any of their towers, you can listen to any agency in the state that isn't encrypted.

As far as audio quality is concerned, it is much cleaner than and analog 154 repeaters. I have been the feed provider for Kent County Fire and EMS for over 10 years. I started in 2012 with and analog scanner in southern Kent County running off the repeater in Harrington with carried some Sussex fire as well as all Kent County fire on dispatch and TAC4. In 2013, I moved to Dover and set my scanner to the Kent Center (Fire/EMS ops center) repeater. My equipment is in the basement and I have a small antenna in the attic for the scanner. I lost the Sussex channels, but I don't consider it a loss as there is a provider for Sussex County. The down side to the repeater channel is I was getting radio skip and bleed-through from Ocean County NJ's radio system. I still get that issue no matter how I adjust squelch or disconnect the attic antenna.

In July 2019, I bought a used PRO-197 and started setting it up. There is a learning curve on this scanner an you really need the software for it. I am using the ARC500PRO for programming. Both my wife and I are former fire/EMS so we enjoy listening to the scanner. I am using the analog input into my feed computer so we can listen as well. There is less overhead on the computer and noise than through the USB programming cable. I know there is a loss of radio tags on my feed but I didn't have them before this scanner. I have compared the audio quality of the 3 feeds in Delaware and my feed seems to have the best quality.

Although I am not and 'official feed provider', in late 2020 an employee at Kent Center tried to set up an official feed from Kent Center. For a feed straight from the ops center, I was surprised at the poor audio quality and its amount of down time. After about 2 months, it quietly disappeared.

 

[N4DES]

Dating back to the NEXTEL SMR days, The P25 Common Air Interface (CAI) receive audio on our previous Mixed-Mode system totally ignored the site noise generated by the IDEN sites where analog reception at the subscriber was plagued with noise that interfered with an analog transmission using the same frequency. So from that perspective P25 is much more tolerant in ignoring external noises that an analog radio would reproduce.

Like others have mentioned, a national digital standard, no change in voice quality or coverage when using DES-OFB or AES encryption, more uniform coverage when paired with simulcast & voting systems, and larger competitive responses to subscriber bids are a number of items as well.

 

[N4DES]

I prefer my P25 audio over the static, crackling and popping of analog and my users enjoy consistent performance throughout the coverage area, and no loss of audio quality on encrypted talk groups.

Amen to that!