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UPC Digital Channel Frequencies?

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  • 26-03-2015 7:37pm
    #1
    bk
    Moderators, Motoring & Transport Moderators, Technology & Internet Moderators Posts: 22,492 Mod ✭✭✭✭


    Does anyone know what frequencies UPC use for their Digital Channels?

    Not looking for this information for any dodgy reasons, I know you can't "tune in" DVB-C channels on your TV. The reason I'm interested in this, is to see what the current configuration of UPC's current network is and how this might effect it increasing Broadband service speeds in future might be.

    We obviously know with the Analogue TV channel frequencies are and it is easy to discern the frequencies broadband use from your own UPC modem. That just leaves the DVB-C channels frequencies to be a mystery.


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    #2
    The Cush
    Registered Users Posts: 15,500 ✭✭✭✭The Cush


    bk wrote: »
    I know you can't "tune in" DVB-C channels on your TV.
    Some TVs have a DVB-C tuner and a number of the channels are unencrypted, maybe someone would be able to check.


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    #3
    L1011
    Moderators, Business & Finance Moderators, Motoring & Transport Moderators, Society & Culture Moderators Posts: 67,818 Mod ✭✭✭✭L1011


    I'll see if I can do a mux scan on my LG TV with a -c tuner. They're getting more common due to standardisation as a number of countries don't encrypt the basic channels


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    #4
    bk
    Moderators, Motoring & Transport Moderators, Technology & Internet Moderators Posts: 22,492 Mod ✭✭✭✭bk


    That would be great, thanks

    BTW that is really interesting, what digital channels are unencrypted? Are they the same as the 17 analogue channels?


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    #5
    dam099
    Registered Users Posts: 1,081 ✭✭✭dam099


    bk wrote: »
    That would be great, thanks

    BTW that is really interesting, what digital channels are unencrypted? Are they the same as the 17 analogue channels?

    I think it may be just RTE1, I accidentally used the DVB-C option when tuning a few weeks ago and it tuned in a load of encrypted channels but only RTE1 was clear.


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    #6
    The Cush
    Registered Users Posts: 15,500 ✭✭✭✭The Cush


    This is a list from July last year - http://www.boards.ie/vbulletin/showthread.php?p=91110196


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    #7
    watty
    Registered Users Posts: 32,417 ✭✭✭✭watty


    They can use any channel between 110MHz and 862MHz, or even higher*. Any downstream channel can be analogue, digital TV or DOCSIS.

    Some cable systems don't reserve 87.5 to 108 for Radio.

    Usually 5MHz to 65MHz (or a band within it) is the upstream channels for Broadband and is very rare now for Band 1 (42MHz to 68MHz approx) to be analogue TV.

    [*Cable used to use only up to 560MHz, but can in theory on latest fibre fed cabinets with shorter coax use over 1000MHz as upper limit. Modern systems allow dynamic reprogramming of channel use and even switched video channels in the cabinet]


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    #8
    Antenna
    Registered Users Posts: 2,306 ✭✭✭Antenna


    It would be interesting if a subscriber with a DVB-C capable TV would make a list of the various MUX frequencies for digital cable for their area, provided that the TV could tune in all the encrypted channels and show the frequency (which is the centre frequency of an 8MHz TV channel MUX )

    I'd be curious to see if any DVB-C cable MUX overlaps with for example amateur radio bands
    particularly
    70cms (430 - 440MHz)
    and 2 metres (144-146MHz)

    or are these frequencies left unused by the cable operators (I suspect they are)?

    Likewise what DVB-C channels could be upset by PMR 446MHz walkie-Talkies if there was signal ingress and one of the cable MUXs goes across 446MHz?.

    There have been postings here in the past about RTE DAB in Dublin degrading/putting noise on BBC2 analogue on Dublin cable, there is no reason why digital DVB-C could not also be affected (causing freezing etc) by other transmissions depending on signal strength and the screening quality of cable, particularly cables and sockets at the subscriber end.


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    #9
    watty
    Registered Users Posts: 32,417 ✭✭✭✭watty


    or are these frequencies left unused by the cable operators (I suspect they are)?
    No they are not.
    The TV won't show channels used for DOCSIS (usually 8MHz in Europe and 6MHz in North America). DOCSIS downstream data is essentially DVB-C modulation and the user data multiplexed using MPEG2-TS. Upstream is CDMA or TDMA (usually TDMA virtual channels) using any desired mix of 0.8MHz, 1.6MHz, 3.2MHz or 6.4MHz channels.
    A modem powered up first tries last used downstream channel, if that fails, then looks at EVERY channel for DOCSIS info in the MPEG2-TS. It then sees the return channel and timeslot to request channels. Then it gets actual downstream and upstream to use, if a valid Modem that's registered, or else it's ignored.

    A spectrum analyser would show channels in use. A TV will only show some in use channels. Perhaps I'll have a look in Limerick. But my HP141T is very heavy. I don't have 1.2GHz plug in, only 110MHz and 18GHz units. But the 18GHz one will cover 10MHz to 1200MHz

    http://www.azur-electronics.com/Pages/hp_8555a_spectrum_analyzer_rf_section.aspx


    It's cable, it's not supposed to leak in or out. Though some areas of bad cable the DAB was leaking in and causing trouble.

    The Users Transmission in same room of 4G Modem or phone on 800MHz will disrupt Modem or TV easily
    Double screened cable and decent F-Connectors helps.


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    #10
    Antenna
    Registered Users Posts: 2,306 ✭✭✭Antenna


    watty wrote: »
    No they are not.

    Watty, actually they are if what is here is still valid (dates from 2002)
    (Technical Conditions for the Operation of Digital Cable Television Systems)

    http://www.comreg.ie/_fileupload/publications/ComReg9866R.pdf

    144 – 146 MHz (amateur 2 metre band) and 430 – 440 MHz (70cms band) Use prohibited (along with aircraft and marine/air distress frequencies)

    I assume due to representations from the IRTS
    two concerns:
    (1) Amateurs not wanting TVI complaints from nearby cable viewers about their 2m/70cms transmissions possibly affecting certain channels on nearby cable TV (even though the fault is not with their own equipment)
    (2) even small amounts of leakage interference would be noticed in amateur bands (analogue TV causing vision buzzing sounds or FM TV audio, digital TV causing increased noise)


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    #11
    watty
    Registered Users Posts: 32,417 ✭✭✭✭watty


    So no wonder Virgin media complained about TV spectrum sell off.
    (which hardly benefits Mobile users at all, just saves Mobile operators some money, and cash influx for all the governments for licence. Theft from TV viewers, esp. the 700MHz band now proposed)

    Anyway, next time I'm feeling energetic I'll measure what there is. Take photos etc.


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    #12
    white_westie
    Registered Users Posts: 619 ✭✭✭white_westie


    On the channel front, after doing a DVB-C scan on my TV a few weeks ago, and going through all the 100+ channels, I found the following 'open'

    RTE1
    RTE1+1 (maybe News not sure now)
    Euronews
    S*y A*ts 2
    B* Sp 2 (surpised at this)


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    #13
    STB.
    Registered Users Posts: 5,380 ✭✭✭STB.


    bk wrote: »
    Does anyone know what frequencies UPC use for their Digital Channels?

    Not looking for this information for any dodgy reasons, I know you can't "tune in" DVB-C channels on your TV. The reason I'm interested in this, is to see what the current configuration of UPC's current network is and how this might effect it increasing Broadband service speeds in future might be.

    UPC Dublin (all at 64QAM @ S/R 6887)

    150000
    166000
    291000
    299000
    307000
    315000
    323500
    339500
    347500
    356000
    364000
    372000
    418250


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    #14
    watty
    Registered Users Posts: 32,417 ✭✭✭✭watty


    Must be an area with poor cabling. 64QAM is low for modern cable.


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    #15
    STB.
    Registered Users Posts: 5,380 ✭✭✭STB.


    watty wrote: »
    Must be an area with poor cabling. 64QAM is low for modern cable.

    Yes that struck me as odd. I grabbed it off a DVB-C dump for Dublin posted on Mediaportal. Of course it could be "Digital" MMDS. That would make sense for the QAM rating.

    The channel block variations for Digital UPC is below, just not the frequencies.

    http://support.upc.ie/app/answers/detail/a_id/256/~/activation-code


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    #16
    bk
    Moderators, Motoring & Transport Moderators, Technology & Internet Moderators Posts: 22,492 Mod ✭✭✭✭bk


    So the overall make up might look like so:

    36 MHz - DOCSIS Upstream (64QAM)
    44 MHz - DOCSIS Upstream (64QAM)
    55.2MHz - DOCSIS Upstream (64QAM)
    61.6MHz - DOCSIS Upstream (64QAM)
    150 MHz - DVB-C
    166 MHz - DVB-C
    176 MHz - Analogue TV
    184 MHz - Analogue TV
    192 MHz - Analogue TV
    200 MHz - Analogue TV
    208 MHz - Analogue TV
    216 MHz - Analogue TV
    224 MHz - Analogue TV
    232 MHz - Analogue TV
    248 MHz - Analogue TV
    256 MHz - Analogue TV
    264 MHz - Analogue TV
    272 MHz - Analogue TV
    280 MHz - Analogue TV
    291 MHz - DVB-C
    299 MHz - DVB-C
    307 MHz - DVB-C
    315 MHz - DVB-C
    323.5 MHz - DVB-C
    339.5 MHz - DVB-C
    347.5 MHz - DVB-C
    356 MHz - DVB-C
    364 MHz - DVB-C
    372 MHz - DVB-C
    408 MHz - Analogue TV (Sky Living)
    418.25 MHz - DVB-C
    471 MHz - Analogue TV (E4)
    482 MHz - DOCSIS Downstream (256QAM)
    490 MHz - DOCSIS Downstream (256QAM)
    498 MHz - DOCSIS Downstream (256QAM)
    506 MHz - DOCSIS Downstream (256QAM)
    543 MHz - Analogue TV
    575 MHz - Analogue TV
    682 MHz - DOCSIS Downstream (256QAM)
    690 MHz - DOCSIS Downstream (256QAM)
    698 MHz - DOCSIS Downstream (256QAM)
    706 MHz - DOCSIS Downstream (256QAM)

    Obviously just a rough idea out of interest.

    The 400Mhz's look like bit of a mess, with Sky Living, E4 and that DVB-C channel all mixed up with lots of unused space around them.

    Looks like plenty of space between 575Mhz and 682Mhz for at least another 8 downstream DOCSIS 3 channels there. Perhaps even an additional 8 in the 400MHz range if they reorganize and clean that range up a bit.

    They might be also able to stick another 4 upstream channels in there at the bottom.

    From above it looks like the Dublin network is built towards a 750MHz plant. Over the last few years they have been rebuilding a lot of the cable network and I assume much of it is 860MHz or even 1GHz. But I assume they can't take advantage of that extra capacity until all the cable in the same area (headend) is at the same level.

    I assume the story is the same for them using 64QAM for DVB-C, I'm sure much of the network is quite capable of higher QAM for DVB-C, as we can see from the DOCSIS channels, but there are probably still old parts of the network that need to be upgraded before the headend can be switched to doing higher QAM levels.

    All very interesting. Thanks for the info.


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    #17
    s_gr
    Registered Users Posts: 314 ✭✭s_gr


    Anyone have the frequencies for the UPC Galway cable system


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    #18
    icdg
    Moderators, Technology & Internet Moderators Posts: 11,519 Mod ✭✭✭✭icdg


    We don't drag up old threads


This discussion has been closed.
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