FW: [EFM] Active Architectures
No problem, a figure would probably have been easier to see it all, but even
a figure ends up being pretty busy. Still, I figured that:
HIGHER PERFORMANCE...LOWER COST...SHORTER TIME TO MARKET
would have gotten a tad more interest.
-----Original Message-----
From: Frank Coluccio [mailto:fcoluccio@xxxxxxxxxxxxxxxxx]
Sent: Monday, August 20, 2001 4:24 PM
To: fcoluccio@xxxxxxxxxxxxxxxxx
Cc: david.m.horne@xxxxxxxxx; sganguly@xxxxxxxxx;
ramu_raskan@xxxxxxxxxxxxx; stds-802-3-efm@i
Subject: Re: Re: [EFM] Active Architectures
Dave, All,
Kindly disregard my earlier question concerning cwdm. I mistook the section
in
question, thinking instead that it was between the head end/OLT and a field
cluster. Apolgoies to all.
FAC
>
> Dave,
>
> > Any interest?
>
> Yes, considerable. Thank you for presenting those views.
>
> Re:
>
> "Downstream, it would be the same as the PON downstream (15x0nm GbE from
PoP
> to splitter; dedicated fibers from splitter to each of 16 (for example)
> ONUs)."
>
> FWIW, a question (and a hint;) :
>
> For extremely long runs, have you considered the tradeoffs of an
inexpensive
cwdm
> solution in lieu of multiple strands coming back from the ONUs?
>
> FAC
>
> >
> > On the topic of active architectures, one that seems attractive in
> > comparison to PON for some deployment scenarios could be called a
> > "half-PON." Below I give a proposal for this. Comments appreciated.
> >
> > The half-PON is a hybrid active/passive architecture that preserves the
> > attractive features of PON and P2P while eliminating many of the
> > unattractive features of each.
> >
> > Downstream, it would be the same as the PON downstream (15x0nm GbE from
PoP
> > to splitter; dedicated fibers from splitter to each of 16 (for example)
> > ONUs).
> >
> > And upstream would be in two pieces:
> >
> > The first would be from the ONUs to the active node (hardened Ethernet
> > switch in node; node also contains the downstream splitter) and has a
> > dedicated fiber per ONU, each to a separate port on the Ethernet switch
in
> > the node enclosure (more details in a second).
> >
> > The second part of the upstream would be a single-fiber 13x0nm GbE
between
> > the node and the PoP (wavelength-muxed into the same fiber as the
downstream
> > so only one fiber between node and PoP).
> >
> > ADVANTAGES AND SAVINGS:
> >
> > The key savings come from the use of low power 850nm transmitters
between
> > the ONUs and the switch, using 100BaseSX (TIA/EIA 785) as the baseline.
So
> > instead of 16 high power (in comparison) 13x0 laser sources (one per
ONU)
> > for PON upstream, each capable of >10km reach thru a 16:1 splitter,
you'd
> > have 16 low power, low cost 850nm sources (one per ONU) that only have
to
> > reach about 300m to the active node, and 1 low power 13x0 (low because
no
> > splitter to go thru) source from the switch back up to the PoP. There
are a
> > couple options on the fiber between the node and the ONU but I'll leave
that
> > discussion for later.
> >
> > Perhaps more importantly though, in comparison to PON you lose the need
for
> > developing and agreeing upon a TDMA protocol, a ranging protocol, a sync
> > protocol, and a contention protocol for requests. You also get uniform
> > transmit power back to the PoP since there is only 1 source rather than
16
> > time-multiplexed from different ONUs at different distances, and no
concerns
> > about run-away transmitter operation bringing down the node. You also
get a
> > management-capable intermediate network point which will allow greater
> > diagnostic, provisioning, and demarcation capabilities.
> >
> > So, ONUs would be significantly cheaper. On this point there is no
question.
> > For reference, a 100BaseFX (13x0 laser, 15km reach) to 100BaseTX media
> > converter goes for about 3-4x the cost of a 100BaseSX (850nm, 300m) to
100TX
> > media converter. Essentially, this is the ONU's function for any of the
> > architectures. Multiply that cost differential by 16 then subtract off a
> > 10km lower power (no splitter to go thru) 1000BaseLX , then add back in
node
> > powering costs. It seems to be an attractive option as a first order
> > estimate (i.e. thousands of dollars in savings per node branch, serving
16
> > ONUs), and powered nodes are a mature technology with lots of cost
reduction
> > tradeoffs that can be made.
> >
> > By the way, I am not presenting this as a replacement for PON, but as an
> > alternative that has not been discussed, and may be more attractive in
> > certain situations. It would also be much less development effort since
all
> > the constituent pieces have a defined Ethernet heritage, which means
shorter
> > time to market. Arguably it is more future proof than PON since it
starts
> > out with 100Mb ports per user, which PON cannot achieve due to TDMA
overhead
> > and guardbands. It also appears cheaper overall than PON, per user (at
least
> > in the early going anyway).
> >
> > In any event it is an alternative FTTH architecture that is decoupled
from
> > the development time required for PON. The primary development effort
would
> > involve adding OA&M to 100Base SX (but there are a couple other
integration
> > decisions to make). The rest of the architecture uses EFM P2P elements
as I
> > envision it.
> >
> > Any interest?
> >
> > --Dave Horne
> >
> >
> > -----Original Message-----
> > From: Sukanta ganguly [mailto:sganguly@xxxxxxxxx]
> > Sent: Sunday, August 19, 2001 9:06 AM
> > To: ramu_raskan@angelfire.com; stds-802-3-efm@ieee.org
> > Subject: Re: [EFM] EFM Requirements
> >
> > Ramu,
> > A all Fiber architecture will be simpler in the
> > overall aspect but would be a extremely expensive
> > deployment. So wo should have some sort of E/O deliver
> > in the last/first half mile.
> >
> > Rich, Vladimir,
> > An active architecture within the field isn general
> > is not a good idea, but actual scenario may digress
> > from generality. Some switching is required, no doubt.
> > I haven't read any deeper discussion on the switching
> > complexity (Maybe I missed some of the discussions in
> > the past.) I also did not understand the assumption of
> > the last/first 0.5 mile being more scalable than PON.
> > What kind of scalability is required at the last/first
> > mile. If you are talking about 1000baseX being
> > distributed to the real consumer or to then the amount
> > of bandwidth that is to be switched is fairly small
> > (i.e. in comparison to the 10G portion). The switching
> > components as far as scaleability and complexity is
> > concerned will be very different and hence, atleast
> > from my point of view is a very different discussion.
> > I think, and you folks may help me understand it
> > better, it is not a good idea to come up with a
> > generic one switching logic which can be applied to
> > 100base-X/1000base-X and 10G network.
> > I would be extremely interested in discussing the
> > active component network on different scale of
> > operation as opposed to a PON as far as cost/ease of
> > deployment and maintainence, complexity etc is
> > concerned.
> >
> > My two cents.
> >
> > Thanx
> > SG
> > (Sukanta Ganguly, An independent view)
> >
> > --- ramu <ramu_raskan@xxxxxxxxxxxxx> wrote:
> > >
> > > Rich, not sure I understand the logic behind some of
> > > your points, but the simple answer appears to be
> > > that it requires new trenching for the new copper
> > > drops, which will never fly. If I misunderstand,
> > > please elaborate.
> > >
> > > I don't quite get you conclusion: 'since E/O is
> > > required, 1KBaseX is significantly more cost
> > > effective, scalable, and simpler than PON.'
> > >
> > > If E/O is required in the field it can't be PON.
> > > Whether it is significantly more cost effective
> > > cannot be judged without detailed designs of each.
> > > Whether it is more scalable I guess depends on your
> > > definition. Simpler is hard to imagine, but again
> > > may depend on definition. If you could elaborate
> > > your view I would be interested.
> > >
> > > Since you are suggesting an active architecture with
> > > new electronics in the field, I for one would
> > > welcome a discussion of such a network architecture
> > > that had fiber for the last thousand feet. No one
> > > has addressed that at all to my recollection. None
> > > of the architectues is perfect in all respects so an
> > > all-fiber active architecture undoubtedly has some
> > > advantages.
> > >
> > >
> > ==================================================================
> > > Vladimir,
> > >
> > > It would seem that the most cost effective approach
> > > for a 10 mile EFM
> > > solution would be to use standard point-to-point
> > > 1000BASE-X or 10GBASE-X
> > > for the first 9.5 miles and then a 0.5 mile copper
> > > tail for the
> > > first/last half mile. Since E/O conversion is
> > > required at the 9.5 mile
> > > mark, standard 1000BASE-X or 10GBASE-X technology
> > > would be significantly
> > > more cost effective, scalable and simpler that PON
> > > at that point. I
> > > expect that there will be switching equipment
> > > located at the upstream
> > > (10 miles away) side, negating any benefit of a PON
> > > split at that point.
> > >
> > > Please tell me what's wrong with this picture?
> > >
> > > P.S. I understand that this does not address the
> > > rural market portrayed
> > > by Frank Miller in this thread, but neither does
> > > PON.
> > >
> > > --
> > >
> > > Best Regards,
> > > Rich
> > >
> > >
> > >
> > > Get 250 color business cards for FREE!
> > > http://businesscards.lycos.com/vp/fastpath/
> > >
> > >
> >
> >
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>
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