Can MOCA traverse a cable TV amplifier?

[rajl]

*Editted to Fix Network Diagram*

Hello,

I lurk on the SNB forums and have read SNB on a regular basis. However, I haven't been able to find an answer to my own small network despite much Googling. Everyone here seems pretty knowledgeable, so I was hoping someone might be able to answer my question.

The question is, can MOCA traverse a cable tv amplifier? I'm looking at extending my home Wi-Fi network to by placing a router in my basement. A requirement imposed by my wife is "no new wires." The previous owners put cable TV in every room when they remodeled, with all but one outlet eminating out from a centrally located amplifier. I was hoping to use this CATV network to extend my LAN.

A network diagram looks something like this:

[Cable Company]
      |
      |
[2-way Splitter] --------------------------
      |                                        |
      |                                        |
      |                                        |
[Modem + router]                    [CATV AMPLIFIER] ---> Rest of House

What I want to do is put a MOCA adaptor by my modem and a another MOCA adapter on the other side of the amplifier where the wiring for the rest of the house is so that I can place a wireless router in my basement. Will this work? If not, why not? If so, do I need a special amplifier (current one is filters up to 1Ghz and provides a passive return from 5-42Mhz), or would the current amplifier work?

I've tried other solutions, but I have had less than optimal experiences. Things I have tried include:
1) Using powerline to create the bridge from modem to basement. The signal degradation is too great for this to be effective (think ~10Mbps throughput).
2) Creating a wireless bridge. It works, but I hate halving my bandwidth due to the Wi-Fi routers acting as bridges/repeaters.
3) Moving the modem/router. Unfortunately, the current position of my modem/router is the best position for getting Wi-Fi on the main and second floors, so moving it is not a preferred option.

Thanks for any help.

 

[thiggins]

No. MoCA does not pass through amplifiers.

 

[stevech]

A WiFi client bridge, i.e., WiFi to ethernet, does not halve throughput.
A WiFi repeater (aka Range Entender) does.

 

[rajl]

No. MoCA does not pass through amplifiers.

http://mocablog.net/faq/

Actually, the the cited web page is unclear and reads both ways. MoCA FAQs state (emphasis added):

Does a CATV amplifier affect the performance of the MoCA bridge?
Yes. A CATV amplifier can block or interfere with the MoCA signal and cause the MoCA bridge to malfunction. Avoid placing an amplifier in the path of the MoCA nodes unless it properly bypasses the MoCA frequencies (850 to 1525 MHz) or use a moCA-compatible amp.

This leads to my question: if an amplifier is in the path of MoCA nodes, what makes the amplifier "MoCA compatible" and what MoCA setups would work with an amplifier. Does a MoCA compatible amp only allow for two nodes to be on the same side (i.e. "amplified" side) of the amplifier? Or would a MoCA compatible amplifier allow for one MoCA node to be on the unamplified/unsplit side and for another amplifier to be on the amplified/split side?

Thanks.

 

[rajl]

A WiFi client bridge, i.e., WiFi to ethernet, does not halve throughput.
A WiFi repeater (aka Range Entender) does.

Thanks for the clarification of terms. I meant a WiFi repeater. What I'm trying to do is get some sort of ethernet connection down to the basement to attached a second WiFi router, which I guess would qualify as a Wireless bridge?

 

[mike_carton]

Thanks for the clarification of terms. I meant a WiFi repeater. What I'm trying to do is get some sort of ethernet connection down to the basement to attached a second WiFi router, which I guess would qualify as a Wireless bridge?

That router would be set up as an Access Point. It is definitely the best option to extend WiFi and (better yet) connect any immobile devices by wire.

About repeaters:
NetGear's range extenders have a "FastLane" mode that avoids the throughput penalty; you can read about it in the SNB reviews of NetGear extenders. I use one with 5 GHz connecting the repeater to the router and 2.4 GHz available for the clients. With the repeater offering the same SSID as the router, mobile devices (excepting some older iOS ones) roam seemlessly.

 

[rajl]

That router would be set up as an Access Point. It is definitely the best option to extend WiFi and (better yet) connect any immobile devices by wire.

About repeaters:
NetGear's range extenders have a "FastLane" mode that avoids the throughput penalty; you can read about it in the SNB reviews of NetGear extenders. I use one with 5 GHz connecting the repeater to the router and 2.4 GHz available for the clients. With the repeater offering the same SSID as the router, mobile devices (excepting some older iOS ones) roam seemlessly.

An access point is definitely what I want to do (if the backhaul is feasible) to extend my WiFi. So the question circles back to the backhaul. Powerline provides a low bandwidth backhaul to my basement (~10 Mbps). The wife won't let me start cutting the walls, floors, etc. to run Cat5/6 from the second story down to the basement. So will the cable TV amplifier I have work with a MoCA adapter on either side of it?

 

[rajl]

That router would be set up as an Access Point. It is definitely the best option to extend WiFi and (better yet) connect any immobile devices by wire.

About repeaters:
NetGear's range extenders have a "FastLane" mode that avoids the throughput penalty; you can read about it in the SNB reviews of NetGear extenders. I use one with 5 GHz connecting the repeater to the router and 2.4 GHz available for the clients. With the repeater offering the same SSID as the router, mobile devices (excepting some older iOS ones) roam seemlessly.

I took a look at the NetGear range extenders. Their "FastLane" is interesting, and Linksys has some new products that appear to be an even better implementation (Netgear uses one band as backhaul and the other for client connection while Linksys dynamically alternates between the two depending on what mix of devices are connected). This might end up being a second-place solution if the MoCA idea doesn't work.

 

[sfx2000]

No. MoCA does not pass through amplifiers.

http://mocablog.net/faq/

Sounds good - seems that there are amps that bypass the MoCA frequencies, but they must be labeled as MoCA compatible...

Side bar question - 2-way/4-way splitters, any thoughts there as they typically will drop 3-5dB loss across the input to output - any insight there? Most tuners/cable modems can adjust to that loss within spec minimums, but some splitters are a bit frequency limited..

Not knowing the answer, but since amps and splitters usually go hand in hand, this could be of relevance to others using/considering MoCA deployments.

 

[Fyodor]

While MoCA can't go back through an amplifier MoCA nodes can be connected to two outputs of a powered splitter (which is just an amp and splitter connected serially). Can you replace first splitter with a powered two way splitter and remove the CATV amplifier? It should work best for the TV too since you want to have the amplifier as far up the chain as possible so that you're not amplifying a muddy signal.

 

[rajl]

While MoCA can't go back through an amplifier MoCA nodes can be connected to two outputs of a powered splitter (which is just an amp and splitter connected serially). Can you replace first splitter with a powered two way splitter and remove the CATV amplifier? It should work best for the TV too since you want to have the amplifier as far up the chain as possible so that you're not amplifying a muddy signal.

No idea. I have thought of doing just that, but have identified that following issues:

1. The first splitter is outside my house. I have no idea why other than that I suspect because it was the easiest and laziest way to do the cable run. Is there way to put an amplifier in front of the splitter without running an extension cord from an outdoor outlet to this location?
2. The amplifier inside my house is an 8-way integrated amplifier/splitter. I could move the amplifier to where the 2-way splitter is and replace my current amplifier with a passive splitter. However, I have no idea how likely splitting my TV signal 8-ways without an amplifier at the split would work in that scenario.

 

[stevech]

Check port to port isolation on splitter. I think most have a spec of attenuation of 20dB or more.
Might still work.

Splitter
vs
Power Divider (rare)

I think the latter has low port-to-port attenuation

 

[jmelan]

Most moca amps really need home run lines to a central location

http://www.pctstore.com/RF_Amplifiers_MoCA_Bypass_Amplifier_s/55.htm

Look at the filter diagram here. This seems to be the best moca compatible amplifier / splitter that I have found. The moca nodes need to be connected after the splitter portion, not in front of the amp.

I recently purchased a ppc entry evo 1-9 off ebay as the above splitter will not fit in my wall

http://www.ppc-online.com/docs/MKTimages/upload/Installation-Guide-9-port-Generic-2.pdf

Another option, perhaps you could use a pair of diplexers to bypass the amp, although that is not an ideal solution.

You could also forget about where to have the router and put in something like a unifi access point for WiFi duties

 

[jmelan]

satellite diplexers to bypass the moca frequencies around the amplifier would be the simple, although maybe not the best solution, more detail with other options and links awaiting moderation

http://www.snbforums.com/threads/help-on-moca-with-cable-amp.2486/

if you do this, make sure to put a moca filter at your point of entry as well

 

[Fyodor]

For the outdoor splitter you can get what's called an amplified drop splitter or drop amplifier. It has a power input that comes back in over one of the coax cables from the inside. You usually buy an accessory splitter that is used at the inside.

So where your cable modem is you get a special T shaped splitter. One half plugs into an ac adapter. The other half goes into the cable modem. The same cable feed that brings your cable data in passes power back to the amplified splitter that sits outside.

I would try something like this combined with regular splitters downstream. I think that the results will be better and your MOCA should work.