Australian Minister Stephen Conroy announced the National Broadband Network would offer speeds of 1 gigabit without spending a penny more of capex. Sounds like the usual politician’s promise. The NBN is a huge issue in the election in 8 days. The opposition wants to kill the $43B project as too expensive; the government warns that a vote against them will condemn Australians to a second rate Internet for a decade or more. Both are right.

Conroy wasn’t lying. The shared 2.4 gig down, 1.2 gig up GPON Mike Quigley has chosen can in fact deliver a gigabit to the home—as along as your neighbors aren’t doing much on the Internet. If three of the 32-64 users on a node want a gigabit, it can’t deliver. Today, so few web services deliver even 100 megabits I’d guess you could get the 800+ megabits gigabit 95% or even 98% of the time. Even in five years, likely traffic patterns would allow actual speeds of 400 megabits or more most of the time. (Assuming GPON’s shared bandwidth can be efficiently divided, which hasn’t even been proven in the lab.)

The capital cost to the Australian taxpayer will be almost the same because the OLT in the exchange is the same standard Alcatel GPON. It will require more robust switches and routers from the exchange to the Internet peering point at modest expense.The OLT in the home may be slightly more expensive, but the chipmakers are making progress integrating the silicon. Charging the customers who want the gigabit $5-10 more per month would easily cover the increased operations costs.

We’ve learned that in practice even dramatically faster speeds produce surprisingly modest increases in total demand. HD TV at 3-8 megabits is the only high volume use. It streams at the same rate whether the connection is 10 megabits or 800 megabits. It’s a joy to get your 150 megabit Microsoft update in seconds with high speeds, but you don’t do more updates because of it.

Hong Kong Broadband Network is the only carrier I know doing customer experiments with a gig over GPON and hasn’t discussed the results yet.

The efficiency of sharing at high speeds over GPON is unproven. I’d very much like to hear, probably off the record, from any well-informed engineer.

10GPON, four times faster, was demonstrated a few months ago by Huawei and Verizon. Commercial units are years away however. Active Ethernet inexpensively provides a full gigabit. It’s being deployed at that speed in Sweden, Singapore, and the Vermont Tel network I consult with. It requires a strand to every home and more lasers, but is a simpler network to manage at high speeds.

For any fiber network built in 2011 or later, the natural speed is a gigabit.