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FTTH DVB-C receiver/splitter?
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FTTH DVB-C receiver/splitter?

VitaVita Member
edited February 2017 in Help

Hi,

I'm interested how do FTTH providers provide internet and TV signal over a single fiber?

I know they use half duplex for the internet, but how does TV signal (DVB-C) work?

What kind of device is needed to send and receive such signal? I know about fiber media converters that are used to convert from single mode fiber to UTP (RJ-45), but how does it work for cable tv (DVB-C), and what kind of device is needed for receiving that?

I appreciate technical answers, as well names of the devices.

Thanks!

Comments

  • I'm more interested in devices that are used to demodulate the signal from fiber. I think they are called CATV receivers, but I'm not sure though.

  • I'm struggling to find any proper information but it's something Virgin Media (formerly NTL and Cabletel prior to that) have been doing in the UK for many years. If you could find more information on their products and history then you may be able to answer the question.

    Hi :>

  • I'm actually unclear on what you're asking, are you asking how FTTB (Fiber To The Building) works and how the fiber is from there converted over to coax? in a whats called HFC (Hybrid fiber-coaxial) for cable-tv? (docsis)

  • ClouviderClouvider Member, Provider
    edited February 2017

    @VPN said:
    I'm struggling to find any proper information but it's something Virgin Media (formerly NTL and Cabletel prior to that) have been doing in the UK for many years. If you could find more information on their products and history then you may be able to answer the question.

    Virgin Media does not deliver pure fibre, it's not FTTH.

    They do offer leased lines and point to point links that are pure fibre, for business, carriers, etc. But I don't think this is what we're taking about here.

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  • @zrunner said:
    I'm actually unclear on what you're asking, are you asking how FTTB (Fiber To The Building) works and how the fiber is from there converted over to coax? in a whats called HFC (Hybrid fiber-coaxial) for cable-tv? (docsis)

    It's unclear because I'm also not sure. I know that one ISP in my region provides Internet+CableTV over fiber. Fiber is half duplex, and it's GPON based. I'm interested in how can they send both TV and Internet over single fiber (what equipment they use, and what do clients need to demodulate the signal). I know about the classic fiber media converters, but what is used for splitting the TV and Internet, what kind of devices?

  • I have FTTH here in Norway, and I think most of the ISPs do it the same way here.

    I have a router with a built in mediaconverter, and a decoder/topsetbox/iptvbox.
    The router have two vlans, one with internet and one dedicated to the tv-streams.
    The topsetbox must be connected (with TP) on a speciffic port on the router to work.

    If you want to use more than one TV, the ISP enables one more port in the router.

    There a no coax, just a singlemodus fibercable.

    As for the decoder/topsetbox I have a rebranded Arris (Pace) with custom firmware/software.

  • Newer PON deployments tend to be IPTV, at least in the US.

    Thanked by 1doghouch
  • ClouviderClouvider Member, Provider
    edited February 2017

    @Vita said:

    @zrunner said:
    I'm actually unclear on what you're asking, are you asking how FTTB (Fiber To The Building) works and how the fiber is from there converted over to coax? in a whats called HFC (Hybrid fiber-coaxial) for cable-tv? (docsis)

    It's unclear because I'm also not sure. I know that one ISP in my region provides Internet+CableTV over fiber. Fiber is half duplex, and it's GPON based. I'm interested in how can they send both TV and Internet over single fiber (what equipment they use, and what do clients need to demodulate the signal). I know about the classic fiber media converters, but what is used for splitting the TV and Internet, what kind of devices?

    It's probably in the IP protocol. I don't think it's too advanced. Likely different VLANs like @noen said, perhaps some extra security to prevent you from playing with it

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  • @Clouvider said:

    @Vita said:

    @zrunner said:
    I'm actually unclear on what you're asking, are you asking how FTTB (Fiber To The Building) works and how the fiber is from there converted over to coax? in a whats called HFC (Hybrid fiber-coaxial) for cable-tv? (docsis)

    It's unclear because I'm also not sure. I know that one ISP in my region provides Internet+CableTV over fiber. Fiber is half duplex, and it's GPON based. I'm interested in how can they send both TV and Internet over single fiber (what equipment they use, and what do clients need to demodulate the signal). I know about the classic fiber media converters, but what is used for splitting the TV and Internet, what kind of devices?

    It's probably in the IP protocol. I don't think it's too advanced. Likely different VLaNs like @noen said, perhaps some extra security to prevent you from playing with it

    Yeah, the "extra security" is encrypted channels, so you can't stream them in like VLC.

    Thanked by 2Clouvider WSS
  • WilliamWilliam Member, Provider

    Vita said: and what do clients need to demodulate the signal).

    A GPON "splitter", these come with either CAT6 Gbit (or 10G) or that + analog or digital TV demodulator to local (depends on country).

    Just because GPON runs on fiber it does not mean you can use a normal media converter and connect a PC (you can, but need few SW layers then) - GPON is encrypted and might carry phone or yea, TV signals on another lane among your and all other users traffic.

    TV is not half duplex in most (makes no sense) - it's IP based with upstream control channel (like on docsis) for pay TV/subscriptions and so on (i had this on UPC cable, A1 sells it in Austria, HT has it here in Croatia).

    The system behind it is similar to docsis:

    • Dedicated VLAN for each service (on GPON: Phone, Internet, TV, Service, Docsis has similar)
    • IPv4/6 Multicast for TV signals (GPON itself is "multicast" encrypted, but this is IP multicast then)

    GPON at best is a better Docsis/Coax anyway, sharing ratio goes down (albeit Docsis goes up in usable spectrum and speed modulation) but it is not dedicated point to point, requiring still in the long run more complex network design.

    It is however cheaper than FTTH and obviously same price to new Coax and cheaper on older install, here they just glue the fiber on your wall, coax is harder to lay by far.

  • @William So, how does Moxi work over FTTH? (waits for head to asplode)

  • WilliamWilliam Member, Provider
    edited February 2017

    WSS said: @William So, how does Moxi work over FTTH? (waits for head to asplode)

    By another protocol for the streaming - this is at last just multicast IP, there are various protocols to transport signals within it - we for example have DVB-S2 over network, which uses the Sat>IP protocol set, able to run in unicast distribution and multicast multipoint:

    https://www.amazon.de/Kathrein-Sat-Tuner-Teilnehmer-Netzwerkstreaming-Ethernet/dp/B012XYXBPQ/

    Even a Dreambox should do that fine, this is just a commercial example for DVB-S2, there should be things for DVB-C also which actually should be easier to capture (we need a specific LNB setup to get all/most channels on sat simultaneously).

    4G ISPs selling home usable connections in Austria also (mostly) give you a small TV box which has nothing to do at all and is another, very simple concept: request RTSP over normal network as unicast stream when turned on, instead of getting all channels which would cause high LTE spectrum usage permanently.

    You can also have this concept behind Coax/FTTH/DSL which happens at times - A1/Telekom Austria has streaming boxes on DSL connections which employ unicast receiving and GPON ones with multicast...

    Thanked by 1WSS
  • WSSWSS Member
    edited February 2017

    @William said:

    WSS said: @William So, how does Moxi work over FTTH? (waits for head to asplode)

    You can also have this concept behind Coax/FTTH/DSL which happens at times - A1/Telekom Austria has streaming boxes on DSL connections which employ unicast receiving and GPON ones with multicast...

    Last I recall, Moxi was a completely closed transport- from the DHCP configuration and network loading- through the content provided. That's why Comcast, Charter, etc eventually kicked them to the curb for Motorola.

    It's a shame- I quite liked my Moxi (when it worked).

  • WilliamWilliam Member, Provider

    WSS said: Last I recall, Moxi was a completely closed transport- from the DHCP configuration and network loading- through the content provided. That's why Comcast, Charter, etc eventually kicked them to the curb for Motorola.

    This is something done on Coax, yea, as it is a dedicated VLAN anyway - you get a kind-of L2 circuit back to the ISP which can run anything. Maybe was multicast, probably unicast though.

    My UPC device is from Cisco (still have it) and custom, was limited to 720p also but this was ~2011 so yea.

    Thanked by 1WSS
  • WSSWSS Member
    edited February 2017

    @William said:
    This is something done on Coax, yea, as it is a dedicated VLAN anyway - you get a kind-of L2 circuit back to the ISP which can run anything. Maybe was multicast, probably unicast though.

    I'm pretty sure it was unicast- but it was a completely closed transport, and despite being Linux based, they even had their own encrypted filesystem (which was tied to various hardware beyond the MAC address- I never was able to decrypt the filesystem from my external drive when it died). The Moxi could do 1080i- it predated HDMI, but did have some strange N-type adapter that nobody seemed to understand.

    Edit: This was more 2001 than 2011.

  • WilliamWilliam Member, Provider

    WSS said: The Moxi could do 1080i- it predated HDMI, but did have some strange N-type adapter that nobody seemed to understand.

    The multi plug standard on beamers and older high end TVs (cba to google, 3-5 cinch plugs, my new beamer still has it) did 720p/1080i as highest, probably that or in the area.

    Thanked by 1WSS
  • @William said:

    WSS said: The Moxi could do 1080i- it predated HDMI, but did have some strange N-type adapter that nobody seemed to understand.

    The multi plug standard on beamers and older high end TVs (cba to google, 3-5 cinch plugs, my new beamer still has it) did 720p/1080i as highest, probably that or in the area.

    Yup. It had those- it's how I connected it to my (then new) Samsung that predated the whole "Listening to you" era of television.

  • hzrhzr Member, Moderator

    FTTH TV here is standard video across internet. Just TCP/UDP packets like other traffic, decrypted by the TV-box.

  • @hzr said:
    FTTH TV here is standard video across internet. Just TCP/UDP packets like other traffic, decrypted by the TV-box.

    How'd you know- spending all of your time on e621 and all?

  • There is a FTTH ISP where I live and they just use IPTV, not sure if it's over the publicly routable internet or a VLAN though, don't have the service myself

  • The device that I got from the ISP is Huawei HG8310, I'm pretty sure they don't do IPTV. Also they offer 60 Analog channels, and 150 digital ones trough one fiber including the internet. They use some other Huawei product but I don't know which one, and that's what I'm interested in, also how do they manage to send Analog TV over fiber with internet?

  • WilliamWilliam Member, Provider

    Vita said: Huawei HG8310

    This is just a GPON splitter with the demodulation/decryption device (ours is from TPLink, as reference) - it has nothing to do with TV.

    Considering they use Huawei for this the backbone is likely also Huawei (considerable discounts) and the box is very likely IPTV over multicast (a solution which both Huawei and ZTE offer, among Nokia and Cisco)

  • VitaVita Member
    edited February 2017

    @William said:

    Vita said: Huawei HG8310

    This is just a GPON splitter with the demodulation/decryption device (ours is from TPLink, as reference) - it has nothing to do with TV.

    Considering they use Huawei for this the backbone is likely also Huawei (considerable discounts) and the box is very likely IPTV over multicast (a solution which both Huawei and ZTE offer, among Nokia and Cisco)

    After a lot of digging I found the box that is used, it's this:

    http://www.videomaxavs.com/userfiles/product_files_shared/H9122_datasheet_en_v1.0.pdf

    The first thing that comes to my mind now, is they can't control who is using their service, unless they run a separate fiber for TV and Internet, am I right? This seems like a simple filter/splitter that converts the optic to RF.

  • WilliamWilliam Member, Provider
    edited February 2017

    Vita said: The first thing that comes to my mind now, is they can't control who is using their service, unless they run a separate fiber for TV and Internet, am I right

    They can, as the VLAN you get on your side can be customer specific (eg. pay TV) or just a normal one (free TV, commercial channels etc.).

    The GPON fiber can carry, in theory, unlimited VLANs and split them up again locally in a bridged network (one ethernet port, then connect TV box there) or direct (2 ports, one for TV box and one for internet).

    EDIT: The Huawei docs on this device say this can split a pre-defined channel (which could be customer specific, but likely is for more than one, eg. again pay and free) to RF, so similar as described but not customer/ISP reprogrammable remotely it seems.

  • Here my ISP use GPON with separate VLAN for telephone (VoIP), TV and internet. They using modem from Huawei/ZTE/Alcatel depends on OLT that they use. STB for TV is an android based

  • VitaVita Member
    edited February 2017

    @William

    This is the thing I'm talking about. As you can see the TV signal is modulated and sent over 1550nm, the network things go over 1490nm, 1310nm. It seems to me like the TV is flowing trough the fiber, the ISP can't know if someone is reading or not, as the device H9122 seems like it does not send any data back to the provider.

  • WilliamWilliam Member, Provider

    Vita said: This is the thing I'm talking about. As you can see the TV signal is modulated and sent over 1550nm, the network things go over 1490nm, 1310nm. It seems to me like the TV is flowing trough the fiber, the ISP can't know if someone is reading or not, as the device H9122 seems like it does not send any data back to the provider.

    Yes, this is a "shared" way giving all access to free channels (if you have a decoding module set to right wave, which should be rather obscure to acquire alone) - you can tap that (like any cable) but there are multiple ways to sell you addon services (configure the device to other wave before delivery, use your internet to auth the TV box which then uses the TV signal, use your internet to get decryption keys for dedicated premium channels, decrypt based on a preinstalled key/smartcard in receiver...).

    Ultimately it seems to be after the splitting not much different from DVB-S2/native DVB-C, just that you can (or rather your ISP could) do more interesting things than on HFC networks, like UPC in Austria on their shared Fiber-HFC.

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