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Comment by throw0101a | Hacker News Reader

No doubt, though I'm also curious about architecture.

Most of these types of deployments tend to go with a GPON variant, with passive optical splitters:

* https://en.wikipedia.org/wiki/Passive_optical_network

However sometimes 'Active' (transitional?) Ethernet is used, which may cost more from a fibre perspective, but the gear at the end can then be traditional Ethernet which allows for taking advantage of economies of scale from the enterprise world:

* https://en.wikipedia.org/wiki/Utah_Telecommunication_Open_In...

Have any details been released on what they're going to use? Anyone have experience with running PON that could comment on the pros/cons?

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It will likely be point to point optical networking (Ethernet/OTN) on these links. Once you get to the last mile, PON (probably GPON for now; XGS-PON is starting to come down in cost now, but is still probably 2x GPON generally).

Point to point kit is cheaper till you get to the customer-facing aggregation, at which point per-port cost of PON vs PtP is much more in PON's favour, and PON customer kit is very cheap from benefits of scale.

PON on the other hand isn't good for long range links. Even amplified (which is £££, and not normally sensible) it has quite a low range compared to point to point at the higher split ratios that make the cost of kit per user so attractive.

> Point to point kit is cheaper till you get to the customer-facing aggregation, at which point per-port cost of PON vs PtP is much more in PON's favour, and PON customer kit is very cheap from benefits of scale.

Is there a cross-over point when one becomes cheaper than the other? Total number of customers, customer per kilometre run, customer/population density, other?

> PON on the other hand isn't good for long range links.

There are certainly 'traditional' Ethernet AOM optics that can reach 40 and even 80 km (before getting into the long-haul stuff from the likes of Ciena), but given that most PONs seem to reach at least 20 km for not-outrageous splitter ratios (1:8 ~ 40km, 1:16 ~ 25-30km, 1:32 ~ 15-20km), how far does one actually need to go for most fibre runs?

A recent video on Utopia Fibre has them using AON, and they claim it ended up generally being cheaper:

* https://www.youtube.com/watch?v=2e9DNwInTE4

* https://en.wikipedia.org/wiki/Utah_Telecommunication_Open_In...

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