On 25/06/18 16:56, Rohan McLeod via luv-talk wrote:
> For example it took me little time to find :
> "Earlier this year, global telecoms company Alcatel-Lucent claims to
> have set a new fibre optic
>  world record with an impressive 31 Tbit/s data transfer over a single
> fibre cable,
>  overtaking the previous record of 26 Tbit/s set by The Karlsruhe
> Institute of Technology
>  (KIT) in May 2011, by a team of German, UK and Swiss scientists."
>  at :https://www.warwicknet.com/blog/how-fast-can-fibre-optic-go
>
> Now this seems to be a more modern  fibre-optic cable from that the NBN
> is laying,

Actually it's probably the opposite (at least outside lab demos).

Oddly enough, the original single mode standard (SMF-28) is actually far
better in practice than many of the things that tried to kill it.
There's some fibres which are now better for specific systems, but given
how well SMF-28 (at least newer versions that are far lower loss) works,
and that optical regen sites are already built on most major routes this
doesn't really matter.

The array fibre NBN used for FTTP is great for their use-case however.

By the way, 31Tbit really isn't that fast, 200Gbit/wave * 96 waves (a
hair under 20T) is in field deployment using kit from the major DWDM
vendors (such as ALU). Whether there's any networks actually populate
their links that big I doubt, but as an example, the last time they
released numbers (several years back) Comcast had inter-city links of
800g in the US, they're likely up to at least 2-3T these days.

For an access network such as theirs the next obvious step after GPON
(what NBN FTTP uses) is probably a WDM-based PON variant. For various
reasons the density would be much lower, but a 32x1g or 16x10g system
should be practical, albeit I've no idea if vendors actually build such
systems. (I do backbone & peering networks at $EMPLOYER, haven't looked
into what's current in the access space in a while).

As for 5G being a practical access technology, it suffers from the same
limitations 4G did before it, just even worse. By the time it's deployed
in a high enough density to be good enough you've not saved much from
just running a cable to each customer.

By the way, if you weren't aware, NBN fixed-wireless is simply LTE (AKA
4G cellular) configured to optimise for non-moving client devices.
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