Combining T1's at one site???

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FMROB
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Joined: Sun Jan 12, 2003 2:28 pm

Combining T1's at one site???

Post by FMROB »

Hello all,

If I have three separate micro hops terminating at one master point (where the voter is going to be located) do I need three separate adtrans at the master site, or can I use one adtran to connect to the three T1's and then break it out to E&M modules? - Rob

Any help would be appreciated.
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FMROB
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Re: Combining T1's at one site???

Post by FMROB »

Bump.... Any help in this would be appreciated, I am specing a job and kinda have to work this out. Thanks, Rob
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psapengineer
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Re: Combining T1's at one site???

Post by psapengineer »

Hi,

If by "Adtran" you're referring to your specific manufacturer of Channel Bank:

In general, T1 circuits are “point to point” where the equipment on the two ends operate like they were "book ends". Normally, you deploy channel banks in pairs, one on each end of the circuit.

So yes, you would typically have 3 channel banks at the location where the voter is if you have 3 remote sites connected by T1s in a hub and spoke configuration.

Regards,
Bob
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MSS-Dave
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What radios do you own?: XTL5K, NX300, PD782, Spark Gap

Re: Combining T1's at one site???

Post by MSS-Dave »

I'll take a general stab at it...

Are each of your T-1's coming in fully loaded? If not, do you have 24 or less TOTAL time slots in use? If so, How about using a DACS like a Adtran MX412. Bring your 3 T-1 in, groom all of the incoming slots to 1 T-1 output then use your channel bank. You can cross-connect any time slot on 1 port to any time slot on another port within the DACS.
I'm doing this now in several apps using RFL and RAD MegaPlex optioned for 2 and 4 wire VF and some E&M thrown in for fun. If you have more than 24 total TS in use between the 3 T-1's, it would seem that you could do it at T-3 level with the proper DACS and T-1 to T-3 MUX in line...

Dave
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FMROB
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Re: Combining T1's at one site???

Post by FMROB »

Dave,

No, I don't beleive so. In each side of the link thee will be one four wire E & M module. All I am looking to do is emulate a wire line for voting receivers.

So it will be like this

Astro Tac Rx'r -- adtran with E & M Module -- motorola ptp 49600 -- motorola ptp49600 -- adtran E & M module -- Unknown modem (to convert analog audio to astro tac 3000.

This will be time three with all three links coming into the repeater site. Any other suggestions.

Also, Has any one had experience with the Astro Tac 3000. I am looking for what equipment I need to get the analog signals to connect to the astro tac 300. Part numbers or any other info would be appreciated.


Thanks, Rob
WB5ITT
Posts: 62
Joined: Thu Sep 01, 2005 8:09 am
What radios do you own?: Motorola, GE, Kenwood, Yaesu

Re: Combining T1's at one site???

Post by WB5ITT »

FMROB wrote:Dave,

No, I don't beleive so. In each side of the link thee will be one four wire E & M module. All I am looking to do is emulate a wire line for voting receivers.

So it will be like this

Astro Tac Rx'r -- adtran with E & M Module -- motorola ptp 49600 -- motorola ptp49600 -- adtran E & M module -- Unknown modem (to convert analog audio to astro tac 3000.

This will be time three with all three links coming into the repeater site. Any other suggestions.

Also, Has any one had experience with the Astro Tac 3000. I am looking for what equipment I need to get the analog signals to connect to the astro tac 300. Part numbers or any other info would be appreciated.


Thanks, Rob
What you need is a drop and insert T1 but why?? Use a 56kDDS instead.....probably cheaper and easier to work with....OUR P25 system uses 56k DDS with Excaliber DAPs (not longer made but there IS a replacement out there by one manf) that takes the V.24 straight in as RS232...9600baud...
IF all you have is a T1, you want the T1 to go from Site A to B to C to the Rptr site....at B and C, it will be DROP AND INSERT.....you will need channel banks at all 4 locations....AINT cheap.....56K DDS is cheaper (maybe!) and they go point to point...you would need a DAP at each end (becomes YOUR CSU that connects to the Telco interface)....so thats 6 DAPs with 3 DDSs or one T1 with 4 channel banks...yeah I think the DAP/DDS would be cheaper overall...

Email me at my call at my call dot net if you need more info and a drawing...

Chris
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Chris WB5ITT
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Motorola, you may find better but you'll never pay more! 😉
George
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Joined: Wed Apr 16, 2003 11:14 am
What radios do you own?: X9000, HT1550XLS, MTS2000, etc

Re: Combining T1's at one site???

Post by George »

[quote="WB5ITT"][quote="FMROB"]Dave,

No, I don't beleive so. In each side of the link thee will be one four wire E & M module. All I am looking to do is emulate a wire line for voting receivers.

So it will be like this

Astro Tac Rx'r -- adtran with E & M Module -- motorola ptp 49600 -- motorola ptp49600 -- adtran E & M module -- Unknown modem (to convert analog audio to astro tac 3000.

This will be time three with all three links coming into the repeater site. Any other suggestions.

Also, Has any one had experience with the Astro Tac 3000. I am looking for what equipment I need to get the analog signals to connect to the astro tac 300. Part numbers or any other info would be appreciated.


Thanks, Rob[/quote]

What you need is a drop and insert T1 but why?? Use a 56kDDS instead.....probably cheaper and easier to work with....OUR P25 system uses 56k DDS with Excaliber DAPs (not longer made but there IS a replacement out there by one manf) that takes the V.24 straight in as RS232...9600baud...
IF all you have is a T1, you want the T1 to go from Site A to B to C to the Rptr site....at B and C, it will be DROP AND INSERT.....you will need channel banks at all 4 locations....AINT cheap.....56K DDS is cheaper (maybe!) and they go point to point...you would need a DAP at each end (becomes YOUR CSU that connects to the Telco interface)....so thats 6 DAPs with 3 DDSs or one T1 with 4 channel banks...yeah I think the DAP/DDS would be cheaper overall...

Email me at my call at my call dot net if you need more info and a drawing...

Chris
WB5ITT[/quote]


Use a CAC or Carrier Access ADIT600 with a 4 port t1 card. This will give you the grooming capability you need to take channels from your three incoming T1's and combine those channels to one T1 to feed your channel bank.

There's plenty of these on Ebay.
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