XPR Prevent Multiple Radios From Connecting Simultaneously (SLR8000 + XPR7550)

[joeradiocheck]

We have a deployment of about 20 radios (all XPR 7550) using an SLR8000 repeater with RAS enabled and Enhanced Privacy enabled. We are having an issue where in certain situations, multiple users (2 to 8 at a time) might click in within a second or two of each other, and the repeater ends up allowing some or all of them through (i.e. it doesn't cause their XPR 7550 to beep and tell them the channel is in use) so they think they are being heard by everyone. What everyone hears, however, is garbled bits and pieces of multiple people talking at the same time. Sometimes nothing is heard but the different radio IDs of the users flash the radio screen.

Is there any setting that will help prevent this? I am thinking something that will allow the repeater a bit more time to select who called in first and who to block. I don't know if the RAS and/or enhanced privacy is contributing to this situation, but those are requirements of our deployment so we cannot disable either.

 

[KG4INW]

I've not witnessed that behavior before, with or without RAS and Privacy, the repeaters do a really good job of only allowing the first person in to speak. What is the subscriber TX Admit Criteria set to?

 

[joeradiocheck]

It is set to Color Code Free (and In Call Criteria is set to Follow Admit Criteria)

 

[Firebuff880]

Sounds like you don't have the TX-Contacts in the channel setup correctly. At least that would be my first guess.

Also, make sure that the system is in Cap Plus mode and that the channels are properly list in the right order and slot numbers.

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[joeradiocheck]

Can you elaborate on the TX Contacts?
We don't currently operate in Capacity Plus mode - is there a specific benefit to this?

I do want to reiterate that some of the time, it works correctly and people are prevented from clicking in when someone else is already talking.

I also want to mention two things I forgot to mention in the original post:
1. The repeater is operating in voting mode. We have a second repeater (SLR 5000) set up for receiving only and it connects to the main repeater over VPN (Fiber, super-fast).

2. Re: Capacity Plus, We are not dead-set on any of the config we currently have. The system was originally set up by a professional radio installer and we assumed everything they did was standard/correct, but that doesn't mean it is. In fact, they discouraged us from using OTA config updates for our radios because they said they could never get it to work properly for any of their customers. On the contrary, we were able to configure it ourselves and it works VERY well.

 

[chrismol1]

I believe this is what enhanced channel access is for , maybe set the admit to color code free , more polite

 

[Firebuff880]

TX-Contacts determines what Group you xmit on by default when you hit PTT.. An no if a Group is busy it's busy. Howevever depending ou your roaming and other configurations it's possible that in IP Site Connect / Digital repeat mode that some radios are on one slot and some are on another thus making it appear that you have a double key on the same group.

Capacity Plus us a way of load balancing your resources and is sometimes referred to a Pseudo trunking.

A satellite Receiver should not be an issue, Talk out is at 25 to 100 Watts depending on a number of things, while Talk in is at 2 to 5 Watts depending on subscriber model. I prefer using SLR-1000 units as full sites to cover things like sub basements over satellite receivers these days, but both are valid solutions. ..

Dealers are as trust worthy as lawyers.

 

[joeradiocheck]

The only area of CPS I see that mentions groups is RX Group Lists
Currently it's configured like this:

RX Group Lists > Digital > List 1 > Channel 1 is a member

@Firebuff880 are you saying that Capacity Plus is better/preferred or just an alternate way of doing it?

 

[Firebuff880]

I can't write your code plug through forum posts and I can't explain what the dealer was thinking when he built this system, but if it's not what you need or expected you should open a dialog.

The TX is a Group or in a few cases Subscriber for private call (YEACH) that a PTT with no other action (selection from contacts or Manual Dial) will TX on. It by default is always first in an RX Group list if one is use or can be specified as the only Group to monitor. When you use an RX group list you are establishing a kind of scan list for that channel (knob position).

I am saying that in my experience Capacity Plus is a better fit for ninety percent of installations because of the why it utilizes and shares resources. But there are six topologies for a reason.

 

[motobot213]

We have a deployment of about 20 radios (all XPR 7550) using an SLR8000 repeater with RAS enabled and Enhanced Privacy enabled. We are having an issue where in certain situations, multiple users (2 to 8 at a time) might click in within a second or two of each other, and the repeater ends up allowing some or all of them through (i.e. it doesn't cause their XPR 7550 to beep and tell them the channel is in use) so they think they are being heard by everyone. What everyone hears, however, is garbled bits and pieces of multiple people talking at the same time. Sometimes nothing is heard but the different radio IDs of the users flash the radio screen.

Is there any setting that will help prevent this? I am thinking something that will allow the repeater a bit more time to select who called in first and who to block. I don't know if the RAS and/or enhanced privacy is contributing to this situation, but those are requirements of our deployment so we cannot disable either.

I hade the same problem when my system was conventional using SLR8000s, RAS, AES. When we had a fire alarm and numerous people were trying to transmit the same issue happened. I never put too much effort since I knew that system would not last. But once we upgraded to Capacity Plus for different reasons I never had the problem again.