BDA w/ MotoTurbo Trunked 800 system.

[Chouk189]

I am currently tasked with bringing in signal from a trunked 800 system for a customer with poor signal strength in their office. I have a couple questions...

1. Are the known issues with using a BDA with a MotoTurbo trunked system?
2. If the answer is no there are no issues, has anyone used the CommScope MR8018?
We are curious about how this product is programmed?


Thank you for your time,

Chouk189

 

[KevinC]

I moved your question to the Industry Discussion forum.

Couple of things to watch out for.

1. Propagation delay in the BDA may be too long to support DMR. I'm not sure what the maximum is for DMR though.
2. The BDA you listed is broadband, so you may (and probably will) be amplifying systems other than the one you intend to. This can cause unintended issues for the other systems.

 

[Chouk189]

Thank you KevinC for your answers. This gives us new things to think about and answers a few other questions we had.


Thank you for your time,
Chouk189

 

[crazyboy]

BDA systems are really something that need to be properly engineered by a professional rf engineering firm if you want them to work correctly.

 

[kayn1n32008]

I am currently tasked with bringing in signal from a trunked 800 system for a customer with poor signal strength in their office...
Thank you for your time,

Chouk189

It might be easier and cheaper to simply install a mobile radio with an outside antenna.

 

[Chouk189]

It might be easier and cheaper to simply install a mobile radio with an outside antenna.

This has already been done, which works great! However the customer wants their portables to work inside their offices as well.

We are currently just trying to fix the issue as efficiently and as cheap as possible. We have a designed BDA system already. We are just looking for cheaper options.

Thank you for your time,
Chouk189

 

[MTS2000des]

Couple of things to watch out for.

1. Propagation delay in the BDA may be too long to support DMR. I'm not sure what the maximum is for DMR though.

We found this out the hard way with P-25 phase 2. The BDA installed as part of our radio project was modified by the vendor and they basically cobbled together one broadband fed by a channelized BDA from another vendor, the reason being channel capacity as required. (Our contract specified a channelized BDA and apparently the original one ordered was limited to 18 channels).

A year and a half later and constant complaints from users of garbled audio and failed transmissions (you got a talk permit but never "made it" on a voice channel/time slot), the vendor sent in an auditor and he agreed with my initial assessment that the delay introduced from propagation and the processing delay (from the filters DSP) resulted in excessive BER and frame slips which resulted in outbound transmissions never leaving the donor.

BDAs are a fine art. Do it right, spend the money to do it well or you will be fighting an uphill battle on a daily basis.

 

[TampaTyron]

Broadband BDAs are tricky with any digital radio system. What type of trbo are you using? Have you considered adding an additional site to the building (and just choose needed talkgroups to pop out to that site)? UHF and 900mhz are easier than 800 for non-channelized amplifiers. There is a ton of experience in this forum and you should get some decent options. TT

 

[kayn1n32008]

This has already been done, which works great! However the customer wants their portables to work inside their offices as well.

We are currently just trying to fix the issue as efficiently and as cheap as possible. We have a designed BDA system already. We are just looking for cheaper options.

Thank you for your time,
Chouk189

Stop. 'Cheaper options" are not going to end well. Do it right, or do not do it at all.

 

[Project25_MASTR]

Probably looking at $20k-$30k for a proper BDA setup if not more by the time things are all said and done. It's as long as it isn't Connect Plus, you'd almost be better off creating a micro-site solution for the building or going with satelite receivers.

 

[TampaTyron]

Perhaps another idea would be to use a pyramid vehicular repeater hooked up to your mobile. Then the portables can talk through the mobile. Probably work well if you only need a talkgroups or 2..... TT.