Fiber Node

"... converts the optical signal to RF ..." Really? For what purpose?

I didn't think much about until he said RF a second time. I feel sure he intended to say "electrical". Shows what can happen working without a script.

What a mess

.... k ...

If you open it up you take the whole system down? really? smh

They recently upgraded our apartment building (390 units) to fiber to the node. They used two CommScope MD6000's (One for each face side of the building since we have a major corridor running the length of the building on each floor) and two power distribution nodes then at each amplifier box they put in new AMPS that connected to the cables going (On the outside of the building) to each unit. This also gave them the ability to segment the building if they need to and in return, they also increased the internet service speed from 50 Mb/s to 70 Mb/s. IT was not economical to wire the individual units for fiber since they could get the same result with this and avoid the installation costs for each unit. (Only about 20%) of the building are actual subscribers.

I worked as a Digital Video headend specialist from 2003 to 2008, operating interconnected SciAtl digital headends, PPV, VOD, guide data, other interactive service, DNCS and digital broadcast acquisition and muxing in two master headends that served about 60 hubsites across 7 west central Florida counties in the Tampa metropolitan area. Like, almost 3 million digital settops in our little corner of the world

So, this is an HFC node. Depending on how Charter is operating their plant, it might operate from aprox 24 MHz to 750 MHz up to near 1 GHz RF. At the headend, broadcast TV is mixed and modulated upon 6 MHz haystacks (digital carrier within a single ATSC analog channel slot) that use old ATSC channel slots to overlay a digital QAM carrier that contains about 10 to 15 standard definition video channels in each of these QAM carriers, or 3 to 5 HDTV in each. Each QAM carrier might operate at 64 to 512 symbols QAM per 6 MHz channel. We operated 256 symbols, which allowed 38.6 Mb/sec per haystack. Th DNCS would give instructions to the digital settops box as far as how to find a digital channel, and authorize decryption of that channel number.

Anyways, this radiates out over fiber "backbones" to distribution hubsites that are about 40km/ 24 mi from the nodes. At the hubsites, gaps in the headend carriers allow for more localized cable channels, ad insertion, VOD, and CMTS channels for cable modem down streams to get combined in. I'm ignoring reverse path of upstream signals from models and settops boxes because that means a longer post. This combined mux of RF signals from aprox channel 2 analog to 107 are then passed to forward lasers, HDFA amps, and light mods that shoot down as a set of already-mixed RF frequencies on a light carrier in the 1550 nm spectrum. When it arrives at the node, all the node needs to do is reconvert this WDM back to RF, and send low and return signals from settops and modems back upstream on the 1310nm wavelength back to the reverse lasers towards the hubsites/headend. Historically since the late 1990's, this is all the HFC node pictures here needs to do. With newer tech the nodes are going to do more, but this is a very slimmed down operation of a Scientific Atlantic CATV HFC plant operation. The physical plant where it transitions from fiber to coax is an active process, requiring local power. This explains the gray "alpha" box. It's a 90 volt DC power supply, with typically enought backup batteries to maintain the copper plant with at least 4 hours of power when grid/mains is unavailable (which can depend on what the local gov stipulated in the build out requirements).

This is so cringy to watch when a lot of what is said here is inaccurate.

Amazing

Paul, is this video a joke? About the only thing you said right was this indeed is a fiber optic node.

It shouldn't loose signal. I open nodes all the time to look for noise and power readings....

Why'd you stop? lol
Great vid

This is ridiculous, weak and limit aggravating. This video is a disaster. U need to go back to a training class.

if you open a node, you dont lose signal. you would need to disconnect the fiber input from the receiver on the inside lid.. the padding and equalizing happens inside the node from the field side of setup, the rest of the padding/EQ-ing comes from the headend or hubsite. this was by far a trash video.. horrible info, ridiculous reverse tilt on spectrum... your narrowcast should be higher than your broadcast to allow for the spectrum to flatten out as it goes to end of line equipment.. as in the high frequencies attenuate faster than low band.. this video hurt my soul a little haha.

I see that THIS "cable system HAS NO "video" services UNLESS it is converted to LIGHT WAVE into that first station...so this MAY be like MAY systems that are dumping "rf" video or video altogether and going INTERNET ONLY...

couple of things , awful set up , you can open the node without loosing signal [ think he means the fiber connector he didn`t know much about ] , SA are fucking muck and a LPi does not change AC to DC , this video has to be from the early late 80s early 90s but only posted 2 years ago ?????

ILOVE cable TV job

Yes you can open the node.

This is the is total slop! You should be ashamed to even put this in any type of video let alone trying to demo a node.

How does the conversation work. Is the optical input digital? Does the modulator modulate the complete baseband (50-1000 Mhz) in one take, or is every tv channel modulatet separately in the node? Or is the complete baseband modulated at the headend and then converted to optical digital (A/D)?

The backup power supply uses regular flooded batteries or special ones.
My cable company asked me for $15,000 if I wanted them to replace the damaged batteries on the node next to my business.

You can open it without losing signal.

That is one messy setup.... my OCD was going off the charts!

really wish to know what brand of this optical node, cause we sell the laser and photo diode as the core parts.

did u just said that if u open your node u'll experience signal interruption? y?