cooldude9919
join:2000-05-29
Cape Girardeau, MO
clubs:
| reply to RoadRunner79
Re: node pics?
said by RoadRunner79  :just for a learning experience what do nodes look like? for example roadrunner nodes I always read about noses this nodes that but what do they look like thanks. I see you are from San Antonio, TX. You should see plenty of nodes around town. Also the amount if fiber time warner has down there is nuts. I was just down there a few weeks ago turning up a new fiber install near the airport. There by the walmart/firestation there is probably ~6 fiber cables going down the road. You can notice them because they have an orange wrapper around them when they pass every pole.
There is a node up on a line for sure right across the road from the applebees there by jones maltsberger. I saw it on my way back to the airport. |
|
Rombus
Premium
join:2007-04-11
Columbus, OH | reply to RoadRunner79
@RoadRunner79:
Sounds like your describing a Tap:
»www.cable-vision.com.tw/images/CATV_tap.jpg |
|
cypherstream
Looking forward to the future of things.
Premium,MVM
join:2004-12-02
Reading, PA
clubs:
2 edits | reply to RoadRunner79
Here's the inside of a Motorola SG-25 860 MHz node:
The gray plastic on the bottom is the fiber slack tray. Fiber goes in there and is coiled up. Then it connects to one of the optical receivers and transmitters to the right. Many nodes are segmentable and can have multiple receivers and transmitters to give each output it's own independent set of narrowcast frequencies (used for VOD and Cable Modems), or they can have duplicate fiber paths for redundancy.
Next up after the node, the coaxial trunk signals must be maintained with trunk amplifiers...
Heres a picture of a C-Cor Flexnet 900 Trunk Amplifier
Here's what it looks like inside:
Remember the node takes the fiber and converts it to radio frequency over copper coaxial cable. Then every so often that radio frequency signal has to be amplified. Its done on those large amplifiers like I show above on what you call RF Trunks. From there they are sometimes 'bridged' to smaller coaxial cables called feeder. Every so often you may see what's called a Line Extender on this feeder. It's basically an amplifier but without as many inputs and outputs or as high amplification as the large trunk amps.
Here's an open line extender made by C-Cor.
Here's a general architecture diagram:
On systems like mine, imagine the green line on the left system as fiber. The circles on the green line would be nodes. Then the red lines are trunks, and along there would be the larger trunk amplifiers. The blue would be regular feeder cable with the occasional line extender.
Newer systems do more fiber and less copper. They place the nodes further out in the path like on the right side of the diagram. Sometimes they rarely need line extenders, unless its a really long run.
Here's the difference. My system doesn't push the fiber as close, but over the years they have segmented nodes and created new ones. It's Node > Trunk Amplifier > Bridger Amplifier > Line Extender > Customer Tap. My system has 750 MHz of bandwidth available. This nets DOCSIS 1.1 cable modem data, 36 HD channels, 77 Analog channels, and a wealth of additional digital channels.
Theres another system near me who pushes fiber much further. Their system is more like Node > Amplifier > Customer. That's it... one amplifier past the node. They run 870 MHz of bandwidth. They have about 77 Analog channels as well, but they have 48 HD channels instead of my measly 36. They also will be doing DOCSIS 3.0 cable modem data, which bonds channels for much faster speeds. They have plenty of headroom for more services.
Whatever system you get, you cannot control. I have been bugging my cable system Comcast (which sucks), to upgrade for years now. They don't listen to their customers (the people who pay their bills). If I had line of sight I'd use DirecTV, but as of where I live right now, Comcast is my only option. |
|
Splitpair
Premium
join:2000-07-29
Cow Towne
 ·T-Mobile US
| reply to RoadRunner79
This is what a Comcast HFC node (post Wilma pre-scrap metal looting) looks like. 
Wayne
--
If you cannot fix it with a buttset and some beanies you ain't a technician.
|
|
RoadRunner79
join:2008-01-19
San Antonio, TX
 ·RoadRunner Cable
| That is cool cypherstream! and the piece i always look at is most likely going to be a tap going by the link they posted but the ones around here have each line that runs to each house pointing down but I am sure it does the same thing. The answers and pics have helped me get a better understanding of how everything works in a bigger picture, and it leaves me wondering how things will turn out for areas like mine that haven't had much upgrading since paragon cable used to be here in San Antonio. It seems everywhere there is new development they might get newer technology but I always wonder what companies do in older areas to keep things up to date. |
|
