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mlerner
Premium
join:2000-11-25
Nepean, ON
kudos:5
reply to news

Re: [TV] FibeTV (HPNA) + OTA on same coaxial?

I wonder why the manufacturer couldn't just use MoCA which is far superior..



ssherwood
Premium
join:2002-02-23
Toronto, ON

1 edit

said by mlerner:

I wonder why the manufacturer couldn't just use MoCA which is far superior..

I think it has to to with interoperability. It is my understanding that MoCA uses frequencies which I believe can't co-exist (easily) with other services found in residential applications, where in theory at least, HPNA is specified to only use frequencies not commonly found on coaxial and/or telephone cabling. The main idea being that for users like me, you can run multiple services over a single cable.

The result is less bandwidth (vs. MoCA), but HPNA v3.1 is supposed to offer 320Mbit (200Mbit throughput). Tests I've read about on this forum with FibeTV's implementation seem to peak at 65Mbit. I haven't found a definitive place listing the version Bell uses, but the modem's page says V.3, and not 3.1 - so I think they are only using 4-36Mhz.

-- SS


mlerner
Premium
join:2000-11-25
Nepean, ON
kudos:5

From what I'm reading is the exact opposite. MoCA is in the 2 GHz+ range, works with digital cable and DOCSIS etc.

They're working on the gigabit spec now I believe.



news

@videotron.ca
reply to ssherwood

25 dBmV rejection doesn't seems a lot to me. Off air signals are very strong, maybe it can be better with high pass filter like MODEL HPF-54H (45 dB rejection) . You have to use good quality splitters, good connectors installed with proper tools, it's suppose to be a closed circuit. I never tried that, so there's no garantee it will works...

»www.3starinc.com/manuals/Filters.pdf



ssherwood
Premium
join:2002-02-23
Toronto, ON
reply to mlerner

said by mlerner:

From what I'm reading is the exact opposite. MoCA is in the 2 GHz+ range, works with digital cable and DOCSIS etc.

They're working on the gigabit spec now I believe.

From »mocablog.net/tag/actiontec/ :

"MoCA has specified 2 frequency bands at which the network can be operated: High-RF MoCA for Cable MSOs and Verizon FiOS from 850-1500 MHz, and Mid-RF MoCA for DirecTV from 500-850 MHz. Our more advanced readers may recognize that cable TV broadcasts below 850 MHz on the coax and satellite TV broadcasts above 950 MHz, hence the need for MoCA to avoid interfering with current signals on the line and 2 separate RF bands."

I may be wrong, but I thought these ranges would interfere with other TV signals, where the sub-band range of HPNA would not.

That being said, I'm the first to admit that I'm not an expert in this area, and will quickly defer...



-- SS


ssherwood
Premium
join:2002-02-23
Toronto, ON
reply to news

said by news :

25 dBmV rejection doesn't seems a lot to me. Off air signals are very strong, maybe it can be better with high pass filter like MODEL HPF-54H (45 dB rejection) . You have to use good quality splitters, good connectors installed with proper tools, it's suppose to be a closed circuit. I never tried that, so there's no garantee it will works...

»www.3starinc.com/manuals/Filters.pdf

Thanks again - will running a high pass filter in series with the diplexer make the rejection stronger?

-- SS


AnonDSLGuy

@telus.net
reply to mlerner

said by mlerner:

I wonder why the manufacturer couldn't just use MoCA which is far superior..

Because the exceptionally high power consumption of the earlier MOCA chipsets kept MOCA from being included in low power, low cost telco IPTV STB's. By comparison, every IPTV STB deployed by AT&T, Bell, TELUS, etc, have an integrated low power HPNA 3.0 chipset (provided by CopperGate, which is now Sigma Designs).

The cable co's with much more expensive, higher power consuming STB's could afford the power requirements of MOCA chipsets, and hence went that route.

Either way its a moot point, G.hn chipsets come out this year and should support gigabit rates on coax or powerline. Since its actually standardized by the ITU-T, it'll probably kill HPNA and Moca in a few years. The next generation of STB's will hopefully have G.hn chipsets (Sigma Designs already has one) built in.