Re: [Bloat] 22 seconds til bloat on gfiber?

[Jan Ceuleers <jan.ceuleers@gmail.com>]

On 26/10/16 03:05, Benjamin Cronce wrote:
> Sorry to side track
> 
> 1:1 split bandwidth wise, still a 1:16 or whatever fiber split. Each
> port can handle 40Gb/s, which is 32 lambdas of 1.25Gb/s, each customer
> getting their own lambda. The ONT can either be WDM-PON or GPON with an
> inline filter. A Google Fiber engineer actually had this in his blog a
> long while back, talking about their design and the "dedicated" aspect
> of an unshared GPON. PON can only handle about a 32 split before the
> signal strength gets too low toe be practical. If each group of
> customers shared a lambda, they would need too many split or repeaters,
> which is more impractical.

I am aware of GPON deployments with splitting factors of 64 and higher,
and these do not (at all) pose a problem with the optical power budget.

> I'm not entirely sure which part you mean "impractical".

What I mean is that the OLT optics become very expensive if you need to
support as many lambdas as you have customers. You'd furthermore need an
OLT port for much fewer customers (e.g. 1 port per 64 or 128 customers)
than the thousands you can support on a (shared) GPON port on a single
lambda.

Also on the ONT side there is the danger of spiraling cost in that I
don't think it is economically feasible yet to incorporate tunable
lasers in the CPE, certainly not across 64 or 128 lambdas, meaning that
you'd need as many hardware variants of the ONT as you have lambdas.

But maybe I'm wrong.