Intermixing Cable TV and Internet Service?

AlphaSys asks: "I live in a small apartment community in the Southeast US. Broadband offerings are great in the area (both xDSL and cable). But the management company for the complex has their own 'cable' system in place by which they distribute programming from their satellite system to the residents. The rental agreement forbids anyone from getting cable service from any other provider (except DirecTV, etc.), which also negates our getting cable internet from anywhere, limiting us only to DSL. Here's where I'm going with this: is there any way the front office folk could get broadband service (T1 or fractional) which they could (via a router and multiplexer) then send down the wire with the regular TV signal like cable companies do? I work in networking but have no knowledge of how cable companies roll the two signals together or how you split it out at the customer end -- I just do Cat5/e/6 and fiber but I want to know if these guys can use their existing wire for this. I've searched Slashdot and googled my eyes out but I really can't find any pertinent information on how something like this is done. Does anyone have any information on how something like this is done?"

Comments

You need to install a CMTS

[Southpaw]

Since the management company essentially has there own cable plant, they can add anything they want to it. In order to have cable modem service, they will need to install some kind of CMTS (Cable Modem Termination System) and use that. CMTS are basically routers with RF catv ports on them. The CMTS will have at least 2 RF ports, one for upstream and one for downstream. Both of the ports will need seperate RF channels, although the upstream channel does not need to be on a channel used by normal tv signals. Most CMTS systems will provide the downstream signal on an intermidate frequency and need a seperate upconverter to translate the signal to a frequency that can be combined with the standard tv signal. For a single apartment complex, try looking at a Cisco 7111 uBR(IIRC the 7111 is one of the few Cisco CMTSs that have a built in upconverter).

Doesn't require CMTS

[nosilA]

The only reason they would need a CMTS is if they wanted to get their own OC3 or DS3 or whatever and provide their own access. The poster simply wants to get cable internet from the local cable company. This cable company may be willing to feed them the DOCSIS portion of the cable spectrum, which the apartment complex could then do a reverse split into their own system.

The only problem with this scenario is that most PCOs (private cable operators) use the bare minimum amount of amplification needed for a decent signal and don't control signal leakage well. This means that the signal strength an carrier to noise ratio in the apartment may be insufficient. But this would be a problem whether or not the PCO installed their own CMTS.

-Alison