Newbie MoCA setup diagram

[Hucsman]

Hi,

We moved recently into a new apartment and had cable installed. With the provided Arris wireless cable modem the kitchen/family room area is not getting a good enough signal. I was thinking about buying a couple of actiontec MoCA adapters to connect the cable modem with a wireless router and create a second wifi area.

Current setup is this:

And I'm planning to do this:

I thought about replacing the initial 3 way splitter with two 2 ways to give the modem the best signal quality possible.

What do you think? Will this work?

Thanks.

 

[CaptainSTX]

Perhaps your diagrams are not complete, but why don't you just install the modem in the family room and then connect your router directly to it? In my opinion, if your diagram is correct, you don't need MOCA.

Assuming I missed something here are several other comments.

1. Each time you split a the CATV signal you have a 3.5db loss. A three way splitter is just two 2 way splitters combined with a 3.5 db loss on one leg and 7 db loss on the legs which have been split again.

2. If you decide to go ahead with MOCA all you splitters need to be checked and if necessary replaced. CATV splitters are reated to 900Mhz and MOCA requires splitters that will work above 1000Mhz.

3. MOCA is designed to pass Ethernet over coaxial cable. If you install MOCA you would normally install the MOCA adapter in tandem with the cable modem or after it. Your diagram indicates to me that you planned to install the MOCA adapter prior to the cable Modem and I'm not sure that would work.

4. You need to review the I/O ports on your proposed Actiontec MOCA adapters. The Actiontec MOCA adapter I have doesn't have any pass through capabilites. It has a single F-fitting for coaxial and a single Ethernet jack.

 

[Hucsman]

Perhaps your diagrams are not complete, but why don't you just install the modem in the family room and then connect your router directly to it? In my opinion, if your diagram is correct, you don't need MOCA.

Assuming I missed something here are several other comments.

1. Each time you split a the CATV signal you have a 3.5db loss. A three way splitter is just two 2 way splitters combined with a 3.5 db loss on one leg and 7 db loss on the legs which have been split again.

2. If you decide to go ahead with MOCA all you splitters need to be checked and if necessary replaced. CATV splitters are reated to 900Mhz and MOCA requires splitters that will work above 1000Mhz.

3. MOCA is designed to pass Ethernet over coaxial cable. If you install MOCA you would normally install the MOCA adapter in tandem with the cable modem or after it. Your diagram indicates to me that you planned to install the MOCA adapter prior to the cable Modem and I'm not sure that would work.

4. You need to review the I/O ports on your proposed Actiontec MOCA adapters. The Actiontec MOCA adapter I have doesn't have any pass through capabilites. It has a single F-fitting for coaxial and a single Ethernet jack.

Thanks for the feedback!

If I install the modem in the family room then I would loose wireless coverage in rooms 1 and 2; and would end up having the same problem but in a different area. I figured out that since the cable drop from the company is in room 1, I should set up the modem in there to have the best signal possible.

Regarding your other points, if a three way splitter is the same as two 2 ways, I might as well keep the 3 way ( assuming it is rated above 1 ghz).

More importantly though, I have to install the adapter in a different cable to the modem as opposed to before it?

 

[Hucsman]

I changed the diagram to have the adapter in tandem to the modem. Would this work better?

 

[stevech]

first splitter should be two-way. That gives the best possible signal to the modem.

In my system, I have, at the cable entry to the house, a bi-directional amplifier (amplifies both up and downstream signals). this offsets the weak signal to/from cable co. due to old and long coax from my house to their demarcation point - and that cable cannot physically be replaced. Note that most cable amps amplify only the downstream and passively pass unamplified the upstream. In my case, the upstream was the problem... in some weather conditions the modem went to max upstream power then lost lock.

If your modem's upstream never increases due to weather or other reasons, you might not need this. Also, my cable ran through the attic of adjacent townhomes to get to the demarcation - and after great struggles, it turns out that there was an illegal 4 way splitter on my coax in a neighbors' house. In place for 15+ years.

 

[RogerSC]

I agree with minimizing splitters...every time you split the signal, the power on the outputs is reduced at least by the splitting factor. The power out of each output on a 3-way splitter is 1/3 of the power going into it (although the other poster indicates that it is actually worse than that). And when you cascade splitters, then you can multiply the splitting factors and divide the input signal to the first splitter by that. For example, by the time that the signal gets to the cable box in the kitchen, according to your diagram the signal has been reduced by a factor of 12.

Where your cable comes in, the MoCA adapter is supposed to be before the cable modem in series with it, and simply acts as a pass-through for the cable signal to the modem; i.e. the cable signal goes into the MoCA adapter, then that goes into the cable modem directly from the MoCA adapter. So you don't need a 3-way splitter there.

Think that I would really take a close look at this in the interest of getting rid of splitters, and consolidating wireless. It may be that if you had a better wireless router, you could put the cable modem and wireless router in room 1 and run MoCA to the family room and put that stuff there on a switch, and your wireless would come from room 1 (or you could have an AP off the MoCA adapter in the family room that provided wireless for the family room, and some wired LAN ports for your entertainment clients in the family room). Or, as has been suggested, have both the cable modem and router in the family room, and then run MoCA elsewhere.

Just some thoughts...I don't know what your physical constraints are, or room size and wall material and thickness, but my initial reaction to this diagram is too many splitters, and not enough consolidation of function (thus needing more splitters than necessary).

Update: Just noticed that the MoCA adapter by the cable modem, in addition to not being in series with the cable modem, is not connected to the router...not sure that will work. That's an argument for having the router and cable modem together, so that you can connect the MoCA adapter that is before the cable modem to the router.

 

[CaptainSTX]

Your new diagram looks like it should work if the signal levels coming into your apartment are OK and especially if cabling is RG6. Digital signals are less effected by being split.

In room one you may want to experiment with which port on the three way splitter is connected to which cable. I would start by connecting the cable feeding the down stream splitter to the -3.5db port. The other two ports are -7 db. The ports on a two way splitter are -3.5 db each.

To maximize your signal levels down stream be sure to use quality compression fittings, make all your connections precisely and avoid using any barrel fittings to splice cable sections.

If this doesn't work for you can always try replacing the three way splitter with an amplified distribution amp.

 

[stevech]

Motorola Surfboard, and other cable modems, have an admin page that displays signal strength up and downstream. On motorola, often it's 192.168.100.1 and that IP can be viewed from a different subnet such as 192.168.1.1.

Upstream: higher power is bad. Means cable system head end asked for more power transmitted by modem to overcome losses end to end. The modems I've owned max out at about 50dBmV. You want far less on average, and it varies by season and other reasons, like 35dBmV.

Downstream: It shouldn't vary much. Something like -10dBmV to 0dBmV is typical. Much less (like -15 or less) and/or high upstream power, means you need a bi-directional amp. My cableco provided one free.


Here's a screen grab from my cable modem (Aris phone+internet). NOTE: because there's a bi-directional amp in my system, the numbers on the modem have to be adjusted ... like the upstreaj is only 25dBm because the amp has 10dB gain. Without the amp, the modem would show 35 dBm in this case. In any event, these are good numberfs.


Downstream
Freq/Power: 615.000 MHz 3 dBmV
Signal to Noise Ratio: 37 dB
Modulation: QAM256
Upstream
Freq/Power: 24.300 MHz 25 dBmV
Channel Type: DOCSIS 1.x (TDMA)
Symbol Rate: 2560 kSym/sec
Modulation: QAM16

 

[Hucsman]

I really thought this through and I believe that there's no way I can use less splitters; no matter how I setup my wireless devices. My logic is this:

I have one cable output (the original drop) and four devices that need a cable input (cable modem, HD Cable box, regular cable box and HD DVR), that is assuming that the MoCA adapters work as pass through devices.

In that case, I have to split the original drop 4 times; and that can only be done with either three 2-way splitters or one 3-way splitter and one 2-way splitter (I believe that both setups yield the same signal loss).