Thursday, 24 April 2014

Tilting at Windmills - Latest scores

Sometimes setting yourself entirely arbitrary objectives can be useful. There's good evidence it helps marathon runners improve their times, for instance. However, sometimes it can be entirely quixotic.

The pursuit of best national broadband speed is in the latter category. While there's perhaps reasons to worry if you're at the bottom of the league tables for broadband (and here's Phil Dobbie doing exactly that for Australia this week), there's really no evidence at all that you benefit from being at the top.

That hasn't stopped countries such as the UK and Korea setting what we might call 'league table targets'. The UK for example has a goal to 'have the best superfast broadband network in Europe by 2015'. This is perilously close to 'if you overinvest in broadband, we''ll overinvest more', though happily in practice the UK is being judicious in its superfast broadband.

Of course the people who most love league table targets are equipment vendors, who benefit greatly from that overinvestment. As I've noted before, the FTTH Council love them. They publish annual data on who has rolled out most FTTH (and FTTB- fibre to the building).

Worrying about FTTH league tables is even more perverse than worrying about general broadband league tables. FTTH is a long way removed from actual consumer or societal benefit, in a chain like this:

If any of the steps in this chain are weak, then the societal return on the investment in FTTH will be less. For example, Martin Geddes argues that increased speeds may not lead to improved technical performance (in the sense of reliable and predictable packet delivery), and may in fact sometimes degrade  it.

My focus in this post is narrowly on the second step in the chain - does increased FTTH adoption lead to increased speeds? Of course FTTH will deliver greater speeds in the last mile - but this isn't necessarily the weakest link in any particular flow of traffic. Problems can occur in many places - the users' device, their wifi network, congestion in the backhaul, congestion in peering and transit links, problems at the content server and so on. If one of these is the binding constraint, then more last-mile bandwidth helps very little. And of course even if the underlying connection is FTTH, the consumer might choose a slower (artificially constrained) product if they aren't willing to pay the premium for higher speed.

One way to test the extent of this issue is to compare levels of fibre adoption to measured broadband speeds from the content server to the end user - if FTTH adoption makes a big difference, we might expect to see a good correlation between these two metrics. Akamai, a content delivery network, publishes national data on just such speeds. While they're not perfect for our purposes (a certain amount of mobile network traffic is likely mixed in, for example), they are the best available. Here are the results for Europe:

Sources: FTTH Council (end 2013), Akamai (Q4 2013)

As you can see, not much of a correlation there (R2=0.01), suggesting that FTTH adoption isn't a magic bullet for experienced speed.

Some of the countries which have been least interested in FTTH to date, like the UK (firmly in the FTTH Council's sin bin), are actually doing just fine on measured broadband speed. Conversely, Portugal, which has spent billions to secure 67% coverage for FTTH and 13% penetration, isn't seeing great speeds as a result.

Of course I'm not saying that there's no linkage between FTTH and national broadband speeds (and South Korea with lots of FTTH/B tops Akamai's speed tables), but the linkage is rather weaker than might be assumed.

The fundamental point here is that to begin with infrastructure targets is to start at precisely the wrong end of the problem. The correct starting point is 'what user experiences do we want to enable?' and to work backwards from this to the required bandwidth, latency, mobility and so on. Then from that you can think sensibly about infrastructure needs.

Otherwise we're arguing about who's tilted at most windmills.

[PS: Apologies for the extended absence, I've been busy with clients, not least on figuring out bandwidth requirements - a post for another day]