DECA Overview / FAQ

Discussion in 'DIRECTV - Coax Networking (private)' started by Sixto, Jul 31, 2009.

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  1. Sixto

    Sixto Well-Known Member

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    The "DECA First Look" looks great, here's a draft of some similar info that I had put together maybe for a future DBSTalk post as people have questions:

    Overview
    • The DirecTV Ethernet Coaxial Adapter (DECA) enables DirecTV to create a DirecTV Coax Home Network. This is DirecTV's implementation of Multimedia over Coax (MoCA).
    • The DirecTV Coax Home Network utilizes the frequency range 500-600MHz within a DirecTV SWM environment, to enable Ethernet (RJ-45) connectivity via Coax to DirecTV receivers.
    • Typically there will be one Coax Network within a home, but there can be multiple Coax Networks, one per SWM port, all bridged to the Home Network.
    Coax Network - Prerequisites
    • DirecTV SWM-enabled environment
      • SWMLine Dish or
      • SWM-8 MultiSwitch(s)
      • The SWM environment allows for the 500-600MHz frequency range needed for the Coax Home Network.
    • DirecTV SWM-capable and Ethernet-capable (RJ-45) receiver(s)
      • DirecTV H21/H23 HD Receiver(s) or
      • DirecTV HR2x HD DVR Receiver(s)
    • Home Network with at least one open RG-45 interface
    Coax Network - New Hardware
    • 1 SWM Filter, to separate the SWM from the Coax Network.
    • 1 DECA for connectivity to the existing Home Network. Power is supplied by 1 DECA Power Inserter (PI).
    • 1 DECA for each DirecTV receiver. Power is supplied by the receiver.
    • Possibly an additional or larger SWM-approved Splitter to provide Coax connectivity.
    • Special Note: Currently the HR20-100 requires it's DECA to be powered by the secondary tuner input, or a separate PI, while the satellite signal is passed to the primary tuner input.
    Step-1: SWM / Coax Network Separation
    • The SWM Filter must be installed after the SWM output, and prior to the first splitter.
    • Typically the SWM Filter will be installed at the SWM PI output, or at the SWM port#2 output.
    • Installation of the SWM Filter should have no effect on the existing SWM environment.
    Step-2: Home Network Connectivity / IP Addressing
    • In order to provide Coax Network connectivity to the existing Home Network and the Internet, there needs to be a "network" DECA installed.
    • The "network" DECA will have three connections:
      • The "Ethernet" RJ-45 interface will be connected to the Home Network
      • The "Sat Rcvr / Power" pigtail will be connected to the power inserter (PI)
      • The "Wall outlet" F-connector will be connected to the SWM environment
    • All network traffic from any receiver on the Coax Network, to any receiver outside the Coax Network or the Internet, will pass through the "network" DECA.
    • Installation of the "network" DECA should have no effect on the existing SWM environment.
    • Note: Instead of installing a "network" DECA, it should be possible to have a DECA-attached receiver with two RJ-45 ports provide the Home Network connectivity by connecting the top RJ-45 port to the DECA and the bottom RJ-45 port to the Home Network. This configuration may be unsupported by DirecTV, and you must be very careful to not create a loop condition whereas there's more then one connection from the Coax Network to the Home Network. This will also cause all network traffic to the Home Network to pass through the DECA that is attached to the receiver providing the Home Network connection, which may affect the network performance of this receiver.
    Step-3: Receiver Network Connectivity
    • In order to provide Coax Network connectivity to a DirecTV receiver, there needs to be a "receiver" DECA installed.
    • The "receiver" DECA will have three connections:
      • The "Ethernet" RJ-45 interface will be connected to the DirecTV receiver port#1 (top)
      • The "Sat Rcvr / Power" pigtail will be connected to the DirecTV receiver
      • The "Wall outlet" F-connector will be connected to the SWM environment
    • After installation of the "receiver" DECA and restarting the receiver, the receiver should have full network connectivity, just as if the receiver was directly connected to the Home Network.
    Notes:
    • Due to the Coax Home Network's use of the 500-600Mhz frequency range, diplexing of OTA into the SWM environment is not supported.
    • DECA-networked receivers can be inter-mixed with direct-attached networked receivers within the home.
    Summary
    • After the proper installation of the Coax Home Network, each DECA-attached DirecTV receiver should perform very similarly as if the receiver was directly RJ-45 connected to the home network.
    DirecTV Coax Home Network Example - Pictorial View
    • Click on thumbnail below.
     

    Attached Files:

  2. Stuart Sweet

    Stuart Sweet The Shadow Knows!

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    Sixto, this is excellent and I think I will make it post #2 in the DECA first look thread!
     
  3. Sixto

    Sixto Well-Known Member

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    I'll tweak it over the next few days ...
     
  4. hdtvfan0001

    hdtvfan0001 Well-Known Member

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    Agreed...nice work Sixto.

    We'll also use it as a "reference" tool as we do our final draft revisions to the First Look itself this weekend.
     
  5. Greg Alsobrook

    Greg Alsobrook Lifetime Achiever

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    Very nice Sixto...
     
  6. dettxw

    dettxw MRVing

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    As I understand it the DECAs connect to each other through the splitters.
    What I'm not seeing so far (above or in the First Look) is some kind of statement to that affect, which is why a SWM setup is required in the first place.
     
  7. Sixto

    Sixto Well-Known Member

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    There's a couple of ways to approach it.

    1) Simply state that a SWM environment is a prerequisite to any Coax Home Network.

    2) Go into the technical details as to why.

    I tried the former (to make it easy for most people). :)

    The technical answer is that a non-SWM environment uses the full spectrum from 250MHz-2150MHz with switching between satellites based on voltage and tone. The SWM environment allows for the easy segmenting of the 500-600MHz range for a Coax Home Network.

    Edit: Added a simple explanation to the overview.
     
  8. 69hokie

    69hokie Icon

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    Good job Sixto...straight forward and to the point. Excellent complimentary document to the First Look.
     
  9. johern

    johern Legend

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    Consider changing

    Special Note: Currently, the HR20-100 requires a separate PI for it's DECA.

    to

    Special Note: Currently, the HR20-100 DECA must be powered from the secondary tuner input or a separate PI, while the satellite signals are passed to the primary tuner input.
     
  10. hdtvfan0001

    hdtvfan0001 Well-Known Member

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    It's in there....you just need to look harder....:D
     
  11. Spanky_Partain

    Spanky_Partain Active Member

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    Now how did you know what DECA stood for! :lol:

    Great work! I gave you some credit on another website today after copying your HD channel guide that gave the resolution for each channel. :)
     
  12. jettech737

    jettech737 Cool Member

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    Looks great, good work Sixto.
     
  13. Sixto

    Sixto Well-Known Member

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    Just played with creating an image to demonstrate the flexibility of the connectivity. Added the thumbnail to post #1.

    [​IMG]
     
  14. litzdog911

    litzdog911 Well-Known Member

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    Excellent work, Sixto! Thank you!
     
  15. jasonki32

    jasonki32 Godfather

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    Great work Sixto!
     
  16. dave29

    dave29 New Member

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    Nice work!
     
  17. Spanky_Partain

    Spanky_Partain Active Member

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    Maybe SWM Filter should be DECA Filter?
     
  18. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I like that too, since "the filter" is, in fact, filtering the DECA and not the SWM signals.
     
  19. Sixto

    Sixto Well-Known Member

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    The DirecTV documentation listed it as "One (1) SWiM Filter", so that's where it came from. Yep, different name might be better.
     
  20. hdtvfan0001

    hdtvfan0001 Well-Known Member

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    I'm actually on board with you guys that DECA filter is a better name, but also concerned that since DirecTV calls it a SWiM Filter, we will be inconsistent. Have to give that one more thought on this end...but I totally agree DECA filter is probably the better choice.
     
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