Re: [802.3_NGEPON] Objectives
Marek, thanks for that explanation.
Ed
Sent from my phone
> On Sep 15, 2015, at 7:37 AM, Marek Hajduczenia <marek.hajduczenia@xxxxxxxxx> wrote:
>
> Ed,
>
> We can always add 25/10G option as secondary base PHY, just like we had 10/1
> in 802.3av objectives
> (http://www.ieee802.org/3/av/tf_docs/10gepon_objectives_0706.pdf). I do not
> see an issue with that, especially if that is what everybody wants. I will
> let Jorge speak to 10G upstream - spec-wise, the effort would be very
> insignificant, and 10G upstream technology already exists, so it is
> something that would come with very little cost, once 25/25G solution is
> available.
>
> Marek
>
> -----Original Message-----
> From: Harstead, Edward E (Ed) [mailto:ed.harstead@xxxxxxxxxxxxxxxxxx]
> Sent: Tuesday, September 15, 2015 7:31 AM
> To: STDS-802-3-NGEPON@xxxxxxxxxxxxxxxxx
> Subject: Re: [802.3_NGEPON] Objectives
>
> That's OK! But just for the record, some vendor input: 25G upstream will
> always be more expensive than 10G upstream. Why:
>
> If 25G NRZ upstream: ~4 dB power penalty, plus need a 25G (vs. 10G)
> transmitter in the ONU, 25G (vs 10G) BMR in OLT If 25G duobinary upstream:
> ~7 dB power penalty, plus 25G (vs 10G) BMR in OLT If 25G PAM-4 upstream: ~7
> dB power penalty, plus needs linearized transmitter (that might have to be
> operated at 12.5 Gbaud vs. 10 Gbaud) in the ONU
>
> The cost premium could be significant, especially in the early years. And
> for residential applications you may not need that symmetrical bandwidth,
> even if there are a few business subscribers sprinkled in.
>
> Ed
> ________________________________________
> From: Salinger, Jorge [Jorge_Salinger@xxxxxxxxxxxxxxxxx]
> Sent: Tuesday, September 15, 2015 7:00 AM
> To: STDS-802-3-NGEPON@xxxxxxxxxxxxxxxxx
> Subject: Re: [802.3_NGEPON] Objectives
>
> What Marek proposes seems like a reasonable approach.
>
> Incidentally, JD, Kevin, Peter, Phil and I got together during dinner. We
> reviewed the objective of supporting 10G US and concluded that we don't
> really need this asymmetry. Supporting Nx25 DS and US is really all we need
> in addition of WDM coexistence with existing 10G EPON and staying silent on
> 1G WDM coexistence. This should also simplify things considerably.
>
> Thanks!
> Jorge
>
>
> Original Message
> From: Marek Hajduczenia
> Sent: Tuesday, September 15, 2015 6:54 AM
> To: STDS-802-3-NGEPON@xxxxxxxxxxxxxxxxx
> Reply To: Marek Hajduczenia
> Subject: Re: [802.3_NGEPON] Objectives
>
>
> Ed et al.,
>
> The concern in the past was about the use of the word "lane" which has been
> used and abused around (not in this group) to the point where it became
> meaningless. Why not just simply state:
>
> Provide specifications for physical layers operating over a single SMF
> strand and supporting the MAC data rate of:
> - At least 25 Gb/s in downstream and at least 25 Gb/s in upstream
> - Up to 100 Gb/s in downstream and up to 100 Gb/s in upstream
>
> The first one would be the base PHY, where the majority of the work would
> have to be done. The second option is essentially a combination of multiple
> base PHYs together into a larger capacity system. As we discussed before,
> once we get 25/25G designed, doing asymmetric 25/10G will be easy (just
> steal upstream from 10G-EPON and put them together, we know that is simple
> enough to do spec-wise). If we have a mechanism to disable lanes in PHY,
> then we do not really need to worry about intermediate speeds and
> combinations - that would become a product problem, rather than a spec
> problem. We would need to specify a protocol to discover the number of
> supported wavelengths, set ground rules for ONUs to play with the OLT, etc..
> but it seems more reasonable than specifying a horde of PHY types.
>
> Marek
>
> -----Original Message-----
> From: Harstead, Edward E (Ed) [mailto:ed.harstead@xxxxxxxxxxxxxxxxxx]
> Sent: Tuesday, September 15, 2015 6:32 AM
> To: STDS-802-3-NGEPON@xxxxxxxxxxxxxxxxx
> Subject: Re: [802.3_NGEPON] Objectives
>
> All,
>
> I thought the table was a great idea, but I am now not so sure. What
> happens if you start with 25 down/10 up, and later you add a 25 down/25 up?
> Sounds like a reasonable scenario. The MAC then must support 50 down/35 up.
> That would be disallowed by the table. You would have to replace all the
> 25/10 ONUs before you could add any more upstream capacity.
>
> As an example, NG-PON2 simply said that any downstream lane is either 2.5G
> or 10G, and every upstream lane is either 2.5G or 10G (it only disallowed
> 2.5 down/10 up wavelength pairs). They did not build a table of all the
> permutations, they never worried that the PON could have a "weird" total
> capacity of, say, 12.5 down/5 up. (I realize a difference is that we are
> grouping all wavelengths under a single MAC, but I'm just trying to make a
> point with this example.)
>
> So I wonder if we should go back to text. What about:
>
> Provide specifications for a downstream physical layer that operates over
> one, two, three, or four lanes of 25 Gb/s each, supported by a single MAC.
> Provide specifications for an upstream physical layer that operates over
> one, two, three, or four lanes, each of which may be either 10 or 25 Gb/s,
> supported by a single MAC.
>
> Ed
> ________________________________________
> From: Curtis Knittle [C.Knittle@xxxxxxxxxxxxx]
> Sent: Monday, September 14, 2015 10:59 PM
> To: STDS-802-3-NGEPON@xxxxxxxxxxxxxxxxx
> Subject: [802.3_NGEPON] Objectives
>
> Colleagues,
>
> Please find attached the PowerPoint file we used this evening to
> consider/massage new objectives. We'll pick up with this file in the
> morning, 8 am EDT.
>
> Curtis
>
>
>
>
> Curtis Knittle
> Director, Optical Technologies
>
> CableLabs
> 858 Coal Creek Circle
> Louisville, CO 80027
> Office: 303-661-3851
> Mobile: 303-589-6869
> Email: c.knittle@xxxxxxxxxxxxx<mailto:c.knittle@xxxxxxxxxxxxx>
>