WA Scan

[kyparamedic]

Our system used to consist of only two sites and we would manually switch between the two. Now that we've added a 3rd site they have set the radios to "automatically" switch. I thought this would be ProScan but evidently not. Instead, the radios don't switch until they lose the control channel, then go to WA Scan, and then pick up the better site. However, sometimes they will go right back to the same one! There are certain areas of town that when you are in a building, the portables continually go into WA Scan and lock right back on to the same site, making a loud beep. Other times they may switch to another one for a minute and then right back to the old one. There is a timing issue on one of the sites so some radios may be on one while others are on a different one, so some radios are about a 1/2 second behind on the audio. It's extremely annoying, not to mention a hassle when you're trying to talk and the radio keeps going to another site.

The other problem is that the mobile radios will stay on one site even though voice communications are all but worthless. The radios used to show which site you were on but now the only way to know is by manually scanning through.

Supposedly ProScan could be enabled on our radios but it would cost several $$$ each, so they opted not to do it. The administration doesn't really see what the big deal is.

Are there any adjustment that can be made to the way WA Scan works so that these problems are less of an issue? It seems to me that the threshold for going to WA Scan needs to be decreased on the portables and increased on the mobiles.

 

[Radioman96p71]

The only way you can get ProScan or ProSound is if the feature is enabled. If you had the 3-site scan that would be perfect for your situation. But if you dont have any of the 3, the only way your radios will search for another site is if they completely lose the one they are on.

The delay in audio is kinda a tough fix too, most likely caused by the method they used to link the sites. The way it sounds, 1 site is the controller and the other 2 connect to it, so the 'controller' site will have no audio delay and the other 2 will since they have to be converted to digital and sent over the link. Only real way to solve that is either move the headend from the site so they are all linked and have the same delay, or fake it and 'link' the primary site inside the same building. Either way is a PITA and if they are too tight to get ProSound on the radios, they will most likely not want to spend the money needed to fix an audio delay issue...

 

[mitaux8030]

There are a few things you can do.
Firstly to get rid of the tone whenever the radio drops off or re-acquires a signal, go to the Alert Options and de-tick the Out of Range Alert Tone box. Then under the System Scan Options, tick the box labelled Tone Suppress. This will keep the radio totally silent as it roams around and switches systems.

It sounds like the mobiles could definitely benefit from raising the threshold at which they enter WA scan. Your portables may benefit likewise... but the risk is that if you're in an area where there is no dominant system and all the candidates are below the threshold... then you'll get no service. The problem with WA scan is that it's not very intelligent as you've identified - and during WA scan, it will scan the system it just lost, so that if the signal was just below the threshold, and then the signal comes out of the fade (you've moved a few inches for example) then the radio will immediately go back to that system.

ProScan is no silver bullet either. While I've yet to work out the exact mechanics of its inner workings, ProScan appears to take measurements when it can of candidate systems (which takes time) and builds up a decision table over several cycles (again this takes time)... all this time taken to make a decision to hand off to another system could mean you lose usable communications all together before an effective decision is made, and then the radio will default to WA scan to find ANY candidate, no matter how weak it may be. Its better, but by no means ideal.

Now you don't mention if you are using a conventional or EDACS system. I'll presume you're using an EDACS system as you mention ProScan (ProSound is an old term I think). Raising the mute / squelch threshold for EDACS systems for WA scanning is something I've not tinkered with, but I suspect it can be done with the RadioMaint suite, by editing the Squelch Levels value. A lower value here will increase the threshold, meaning a stronger signal will be required to open the squelch. Perhaps try setting it to a ridicuously low value like 10, and see the effect.
Give it a go, and if it doesn't appear to work, return the value back to the original setting. Do not set this value above 158, or strange things will happen.

If you're using conventional systems, then simply raising the Squelch Level value under the Power Up Options will achieve this. (this won't apply to every radio type though...)

 

[greenthumb]

Are there any adjustment that can be made to the way WA Scan works so that these problems are less of an issue? It seems to me that the threshold for going to WA Scan needs to be decreased on the portables and increased on the mobiles.

WA SCAN is what it is and it won't kick in until the radio loses the control channel. It can't be tweaked at all, and I wouldn't recommend adjusting the squelch settings to make it lose the control channel sooner because you are effectively decreasing the range of your system by doing so. WA SCAN is NOT a suggested means of roaming between sites, they need to purchase ProScan and do it correctly.

You're public safety, not Walt Disney World. They need to make it work right.

 

[kyparamedic]

The only way you can get ProScan or ProSound is if the feature is enabled. If you had the 3-site scan that would be perfect for your situation. But if you dont have any of the 3, the only way your radios will search for another site is if they completely lose the one they are on.

I think some radios may have ProScan enabled, but our older radios do not and they don't want to pay to upgrade each one. Most of us carry LPE-200's while the administration carry P7100's and P5400's.

The delay in audio is kinda a tough fix too, most likely caused by the method they used to link the sites. The way it sounds, 1 site is the controller and the other 2 connect to it, so the 'controller' site will have no audio delay and the other 2 will since they have to be converted to digital and sent over the link. Only real way to solve that is either move the headend from the site so they are all linked and have the same delay, or fake it and 'link' the primary site inside the same building. Either way is a PITA and if they are too tight to get ProSound on the radios, they will most likely not want to spend the money needed to fix an audio delay issue...

The audio delay didn't come about until around months ago. As best I can tell, our "system" used to operate as two separate systems and were patched together in dispatch. On the dispatch console they would actually do a multi-select even when using just one channel. They would select channel A on site 1 and channel A on site 2. When someone keyed up on channel A on site 1, it would patch it to channel A on site 2. If you were on site 2 when someone was talking on site 1, you would see dispatch's ID number instead of the radio ID number. With the addition of the 3rd site, everything appears to be working together. The delay wouldn't be that big of a deal except for the fact that when it's a multi-agency response, they dispatch us all simultaneously. We share stations with the fire dept. and they still operate on VHF, so we're hearing the same dispatch come over the station speakers with a noticeable time difference. Talk about annoying!

 

[kyparamedic]

WA SCAN is what it is and it won't kick in until the radio loses the control channel. It can't be tweaked at all, and I wouldn't recommend adjusting the squelch settings to make it lose the control channel sooner because you are effectively decreasing the range of your system by doing so. WA SCAN is NOT a suggested means of roaming between sites, they need to purchase ProScan and do it correctly.

You're public safety, not Walt Disney World. They need to make it work right.

I agree 100%, but it doesn't really affect the administration of bean counters so they don't really care. Honestly I think it would be better to take WA Scan off and just have us do it manually like before. Unfortunately we have some people that for the life of them, can't remember to switch sites and are on scene with no way to contact them. These are the same ones that also can't remember to turn off their portable when getting in the truck either.