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Discussion Starter #1 (Edited)
DECA, the cheap alternative to MoCA for Tivo, HTPCs and Extenders

Thanks to user Dave Harper, I discovered a great solution for ethernet over coax which is much cheaper than MoCA. It does have caveats, but is a great fit for Tivo, Mini, HTPC and extender systems.

DECA is DirecTV's version of MoCA. But DirecTV DECA hardware is much cheaper than MoCA hardware, especially if you buy on ebay or Amazon. MoCA is designed to work on the same wires as cable TV signals without interference. But DECA is right in the middle of cable TV frequencies, at 450-650mhz, which makes it impossible to run cable TV and DECA on the same wires. However, since Tivo and HTPC users typically don't need cable TV signals anywhere except at their tuners and cable modems, the rest of the coax network can be disconnected from the cable TV network and be dedicated to DECA only. DECA bandwidth is 100Mbps full duplex, so should be sufficient for most video streaming needs.

Essentially, all you need to do is connect a powered DECA adapter at a router or switch and another powered DECA adapter at every extender. DirecTV makes several DECA devices to do this, including older DECA I receivers and the Cinema Connection Kit, or the newer DECA II devices. I used the latest DECA II devices because it was easy to find kits that included a power supply, and very inexpensive. So just buy one of THESE DCA2PR0-01 kits for each node in your network. Older DECA devices and power supplies will also work fine.

Here is the DECA II kit needed for each node. At your switch or router, simply plug in the power, connect the DC/RF adapter then connect to the short cable attached to the DECA device, then connect an ethernet cable from the DECA device to a port on your switch or router. At each Mini or extender, connect power in the same manner, connect the other coax port to your coax network, and connect ethernet from the DECA device to your Mini or extender. 2 solid green lights on all DECA devices mean you have a good connection. Amber means you have a bad connection, so check your wiring.



If you are interest in power usage, my Kill-A-Watt says each of these uses 3W.

These adapters use Entropic MoCA chips shared by many MoCA devices like Actiontec, ChannelMaster, Hirschmann and Wi3. The main difference is the different frequencies used by DECA.

Here's one vendor:
http://www.amazon.com/DIRECTV-Broadband-DECA-Ethernet-Adapter/dp/B00ZDUQVFU ($7.50 each shipped)
 

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Now everybody will be bidding them up on eBay!
 

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Quote:
Originally Posted by Sammy2  /t/1473583/deca-the-cheap-alternative-to-moca-for-htpcs-and-extenders#post_23336292


Now everybody will be bidding them up on eBay!
Shhh. That's mdavej's plan.
 

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I take that the other end of the adapter just gets capped off and not connected to anything at all?


Also, what is the DC to RF adapter for?
 

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Uhhhh, DC to RF!
No, one end is power (the DC to RF adapter plugged into the power supply) and the other is to the coax network as mdavej mentioned.


PS - There's a DC to rf adapter because as I said in the original post, DECA is usually powered by the DTV receiver itself, but when they use it separately to inject ethernet in a location that may not have a receiver present, they use the power supply and those DC to rf adapters to get the deca some juice.
 

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Quote:
Originally Posted by cdru  /t/1473583/deca-the-cheap-alternative-to-moca-for-htpcs-and-extenders#post_23336376


Shhh. That's mdavej's plan.
Actually at was MY plan from the beginning. I bought out all the DECA equipment and am hoarding it in hopes of high demand since these threads are going viral. Why do you think I dropped that little "hint" about using DECA in the first place!?!?!?
 

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Discussion Starter #7

Quote:
Originally Posted by cdru  /t/1473583/deca-the-cheap-alternative-to-moca-for-htpcs-and-extenders#post_23336376


Shhh. That's mdavej's plan.
Mwahahaha... all the pieces are falling into place (rubs hands)



But seriously, I figured this would have very limited appeal anyway. Only uber-cheapskates like me would be interested in such an approach. Either that, or Dave is actually giving me a commission on all his ebay sales
 

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Nothing is wrong with it but if you have installation issues it can be easier to utilize cabling that is already in place.
 

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Discussion Starter #10

Quote:
Originally Posted by Mfusick  /t/1473583/deca-the-cheap-alternative-to-moca-for-htpcs-and-extenders#post_23337628


What is wrong with good old fashioned CAT6 cable from monoprice?


It works wonderfully and costs almost nothing.
The timing belt for my car costs almost nothing as well, but the installation is a *****.
 

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Quote:
Originally Posted by mdavej  /t/1473583/deca-the-cheap-alternative-to-moca-for-htpcs-and-extenders#post_23338374


The timing belt for my car costs almost nothing as well, but the installation is a *****.

LoL. So true.
 

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MoCA 1.0 goes up to 130 Mbps, MoCA 1.1 goes to 300 Mbps, MoCA 2.0 supposed to go past Gigabit.


100 Mbps is fine for individual extenders, but HTPC will have to be on a faster connection, since it will serve all those extenders, and can easily max out 100 Mbps with 4-5 streams. IF you have network tuners, double the needed bandwidth coming in and out of the HTPC.
 

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I like the the look of the DIRECTV Cinema Connection Kit (DECABB1R0) box better than the dongle device. Any reason I can't use two of these (at the router and remote TV end points)?


I was briefly tempted to go with the MoCA 2.0 option, since that supports 1.4 gigabit bandwidth, however it operates at coax frequencies higher than the el-cheapo splitters used by

cable installers, and finding a replacing them all would be more work than pulling dedicated CAT6 to my problem location.


I suspect DirecTV chose the DECA frequency in the 450-650Mhz range, precisely because they wanted to piggy-back on already installed coax done by Cable providers.
 

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Discussion Starter #15

Quote:
Originally Posted by aufVidyZen  /t/1473583/deca-the-cheap-alternative-to-moca-for-htpcs-and-extenders#post_23344223


I like the the look of the DIRECTV Cinema Connection Kit (DECABB1R0) box better than the dongle device. Any reason I can't use two of these (at the router and remote TV end points)?


I was briefly tempted to go with the MoCA 2.0 option, since that supports 1.4 gigabit bandwidth, however it operates at coax frequencies higher than the el-cheapo splitters used by

cable installers, and finding a replacing them all would be more work than pulling dedicated CAT6 to my problem location.


I suspect DirecTV chose the DECA frequency in the 450-650Mhz range, precisely because they wanted to piggy-back on already installed coax done by Cable providers.
Should work, as these all the DECA devices are supposed to be interchangeable, but I don't know for sure.


FWIW, all mine are completely hidden from view, so it doesn't really matter what they look like. I don't use the tiny patch cables that come with this things. I use normal 3-4 ft cables so the device can be placed anywhere I like.


Let us know how it works out.
 

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Quote:
Originally Posted by aufVidyZen  /t/1473583/deca-the-cheap-alternative-to-moca-for-htpcs-and-extenders#post_23344223


...I suspect DirecTV chose the DECA frequency in the 450-650Mhz range, precisely because they wanted to piggy-back on already installed coax done by Cable providers.

They chose those frequencies because they don't interfere with their satellite's frequencies running down the same coax. It's for the same reason cable does it, just the inverse.
 

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It is important to understand that DECA is NOT full duplex. MoCA, like most other RF-based systems, is half-duplex. One node in the system (typically the one with the best signal measurements) decides which node can be talking at any one time.


MoCA 2.0 is supposed to improve the bitrate by a factor of four (400Mbps), not a factor of 10 but as pointed out, MoCA 2.0 devices have yet to be approved (low or high carrier frequency).
 

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Not sure about bumping rules, so let me know if I shouldn't have here.

My plan is to use our existing Coax to run a connection to two rooms that will have Xbox 360s running as WMC extenders.
Will these adapters allow for simultaneous connection to both extenders? (Both watching TV at the same time) There will be one adapter behind the main WMC PC, and one more in each room behind the extenders, for a total of three.

Also not sure if our setup will even allow any of this. We don't have internal wiring, it's all connected to a hub (?) mounted on the side of the house. We're currently using DirecTV whole home dvr service, and plan to switch everything to FiOS (Not sure if that's relevant) This is what it looks like. The white cable leads to the satellite, cable labelled 1 leads to the main Genie receiver, 2 and 3 lead to two Genie Minis.

Thanks for the help!
 

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Not sure about bumping rules, so let me know if I shouldn't have here.

My plan is to use our existing Coax to run a connection to two rooms that will have Xbox 360s running as WMC extenders.
Will these adapters allow for simultaneous connection to both extenders? (Both watching TV at the same time) There will be one adapter behind the main WMC PC, and one more in each room behind the extenders, for a total of three.

Also not sure if our setup will even allow any of this. We don't have internal wiring, it's all connected to a hub (?) mounted on the side of the house. We're currently using DirecTV whole home dvr service, and plan to switch everything to FiOS (Not sure if that's relevant) This is what it looks like. The white cable leads to the satellite, cable labelled 1 leads to the main Genie receiver, 2 and 3 lead to two Genie Minis.

Thanks for the help!
I'm about 99% sure that MoCa is compatible with cable/fios but incompatible with DirecTV, whereas Deca is compatible with DirecTV but incompatible with cable/fios.

If you won't be using the existing coax for either (as in your coax will come in and connect directly to your modem/and or tuner) then you can just keep the coax used by your extender network separate from the coax used for the actual cable signal and it won't matter which one (MoCa or Deca) that you use.

But as you've described it, you should be able to run two extenders off of MoCa bridges without any trouble. (the quality and condition of your coax can effect that among other things)
 
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I'm about 99% sure that MoCa is compatible with cable/fios but incompatible with DirecTV, whereas Deca is compatible with DirecTV but incompatible with cable/fios.

If you won't be using the existing coax for either (as in your coax will come in and connect directly to your modem/and or tuner) then you can just keep the coax used by your extender network separate from the coax used for the actual cable signal and it won't matter which one (MoCa or Deca) that you use.

But as you've described it, you should be able to run two extenders off of MoCa bridges without any trouble. (the quality and condition of your coax can effect that among other things)
My hope is that the line to the tuner will be direct from the Fios ONT and won't touch the existing cables. I've read a lot of threads and everyone has been very vague as to whether they've been able to use more than two DECAs to connect multiple rooms, or if they put a switch on the far end then routed to other rooms.
 
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