Chad, this is an interesting challenge.
I need some info.
1. What type of Aurora nodes are you using? (I am assuming that Node A is also Aurora.)
1. What type of amps are in cascade from Node A?
2. Do they have the same 30 MHz diplex as the plant off of Nodes B,C, and D?
3. How are you currently getting the forward RF off of the A nodes amp cascade onto the nodes A,B, and C? I am assuming a TX at the cabinet, feeding fiber.
4. What is the setup that's gets your return back onto the RF amp cascade? I am assuming that there are RX's in the cabinet which are combined, and then combined or diplexed back onto the RF amp cascade, or a terminating amplifier.
5. In the RF cascade from node A to the cabinet, is this all "trunk" cable, or is part of this distribution with taps? Any trunk splits?
6. What type of CMTS are you using, and are more ports available other than the one for Node A?
I'm pondering..........
In your experiment, you might be able to convert a frequency to another, but unless those modems and the CMTS port have have been configured for the new frequency, nothing will happen. Remember that the CM gets the US freq once it has found the DS, and all subsequent communication between the two go from there. You will need an unused US port to perform this. I can't see why this wouldn't work though.
The problem of the noise on the return path from Node A however will still be there. And if the diplex filter BW is still cutoff at 30 MHz, what good will it be to up convert? As I see it, you have to get back through those 6 amps from the cabinet. The frequency stacker solutions that have been proposed won't work, because they are based upon having a fiber return all the way, which you do not have.
What could work would be to up convert the returns at the cabinets to 3 different frequencies ABOVE the BW of your forward system, and diplexing them back onto the coax before whatever termination you are currently using. I.E. a diplex filter that has a freq split at say 600 MHz. In addition to this filter, you would need 2 more at each amplifier and/or splitter location back to node A. At this point you could feed the diplexed output into a TX for transport back to the HE,(if you have a spare fiber and cabinet) then down convert to frequencies your CMTS can handle. You would now have 4 individual returns to present to your reverse combining network and the CMTS. That's the analog version.
A better way would be to digitize the outputs of your RX's at the cabinet, mux them together, and send them back at a sub band frequency other than your current CM frequency. Use a diplex filter to insert them into the RF amp cascade, and high pass the common leg feeding the forward system. At the headend, feed a demux from the Node A return to separate your returns back out. At this point how you combine them into your reverse combining network is up to you. The threshold for noise on the digitized carrier is much lower than the analog CM carrier you are now using.
I belove that the Aurora nodes already digitize from the node to receiver, and this may screw up the digitized "digitized" signal, I just don't know. Call Aurora and find out, they have excellent tech support.
Check with Aurora, they may have a solution similar to this right now. Or, since you are close to them, they might come out and experiment a little!
Hope to hear from you,
KableGoddd
Re: need upstream data help
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Kent Binkerd
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