Of recent days it has become increasingly apparent even to the layman that Malcolm Turnbull’s broadband policy is a dud. There are no redeeming features (it’s not cheap, it won’t be deployed faster, & the cost/benefit of the policy is hard to see in a positive light) & Turnbull is refusing to answer deeply technical questions on the policy that should be instantly answerable, if not in the policy itself. Even Seven’s Sunrise was in on the dogpile of anti-Coalition broadband policy, their only criticism being that the rollout isn’t quick enough.
While they may not know why the plan is destined to fail, there is definitely a feeling of “why bother” when it comes to saving so little to deploy such a step back in technology.
The biggest hurdle for the Coalition’s plan is to convince technical experts that the Coalition can break the laws of physics & deliver a minimum of 25Mbps to every Australian (& 50Mbps to 90% of Australia). This will be a hard case to build as there is so much evidence to show that these speeds would not be viable in Australia. Even as far back as 2004, Telstra, then under the direction of Ziggy Switkowski, stated that they had no interest in trialling, let alone deploying, VDSL2 to Australia, stating that they “see fibre to the premises as the most likely technology to support very high speed access services of the future”. Yep, that’s 9 years ago that Telstra had no interest in using copper to deliver very high speed broadband.
Why would they say this? Is it that they know what’s deployed in the network & realise that they’d see little improvement over ADSL/ADSL2? Of course it is. Telstra well know that the copper deployed is just not up to the task of running VDSL, let alone VDSL2, & it’s not just because of faults.
The reality is that little of Australia’s copper on the distribution side (what matters for FTTN) of the network is over the 0.64mm diameter cable (aka: 22 AWG) that VDSL2 requires, much of it is in the 0.40mm & below class, with some newer areas having 0.50mm deployed. The only places I’ve come across with 0.64mm & above cable are rural areas. Most of the 0.64mm & 0.90mm in the bush is long line PSTN with loading coils. Essentially the higher gauge was used to extend a phone line out to a farmstead or the like.
The main reason for doing this is the cost of copper, Telstra couldn’t afford to deploy 0.64mm over 0.40mm due to being more than twice the weight per metre, that’s a lot more cost in both cabling & transportation. Essentially what Telstra (or Telecom or even PMG) did decades ago is the same thing the Coalition are doing now: saving money at the cost of future-proofing. While it may have been prudent in a phone-only world, the world of high speed networking takes no prisoners when it comes to myopic deployment of networks.
Having looked into BT’s solutions & read what experiences many are having with their FTTC network, it’s clear that the same solution just doesn’t fit into Australia’s telecommunications environment. In the UK, those that are able to achieve higher speeds have almost no attenuation on their lines. Looking through the DSL Reports forum, we can see many UK customers posting their speeds & line attenuation. These real world examples show how low attenuation really does have to be to achieve anything close to BT’s “up to” limit of 79Mbps.
Even with line attenuation of 7 dB, users are still not able to break 70Mbps, leading me to believe that 50Mbps will be laughably impossible. Looking at the attenuation of the cable gauges deployed in Australia, we can see that even without taking in the dB loss from joints in the cable, loop lengths will have to be tiny to even achieve 25Mbps.
0.30mm = 30 dB/km
0.40mm = 25 dB/km
0.50mm = 20 dB/km
0.64mm = 15 dB/km
0.90mm = 10 dB/km
These are approximate dB/km measures & assume mid range cable (not the highest quality) to compensate for older infrastructure. So, we can see that in countries like the UK & Germany, with their mostly 0.64mm cabling, are sitting near the low-attenuation end of the above list, averaging around 7.5dB for a 500m copper run. With this amount of attenuation you will receive just under 70Mbps at 500m, not too shabby for a copper line service.
By adding in connectors (~0.5db loss per termination point, joints can be even higher) & the true state of Australia’s copper cabling, we can assume that the speed vs distance quoted on most VDSL2 profile graphs are 1/2 to 1/3 the distance quoted. So in the graph on the left, we can see that with a line attenuation of 13.8dB/km, 25Mbps speeds are achievable at the 3000ft (900m) mark & below. If we modify the speed to represent actual line attenuation in Australia, that number comes out closer to 25Mbps @ ~380m from the node. That’s quite a small run considering to get to the pit out the front is around 20m from the first socket into the house.
With this in mind, it’s easy to see why telecommunications professionals are up in arms about the claims put forward by Turnbull. There’s few options for a base speed of 25Mbps to be achievable, both being rather expensive.
Firstly, the loop length of all services can be kept under 400m by deploying more cabinets. The amount needed for every copper service in Australia to be on no more than 400m is hard to judge, but with the estimate of 60 000 nodes required for a “less than 1km” loop length (as Turnbull has said previously), less than 400m could mean over 100 000 cabinets.
Secondly, the copper can be upgraded to 0.64mm diameter or above cable. This would make little sense as the same cable Turnbull is claiming could be used but is being ignored by the ALP’s NBN would not be used by the Coalition’s NBN.
Both solutions would increase the cost of an FTTN deployment by magnitudes, & neither would be a future-proof solution.
The more logical option for Turnbull is to revise down the minimum speeds & essentially trash his own policy, all under the guise of “better economic management”. If it is good economic management to knowingly deceive voters by claiming your substandard plan for broadband in Australia is a viable alternative to the current plan, then I’m at a loss. As I demonstrated recently, the upgrade to VDSL2 & then vectoring will impose far more of a financial burden on the government than going straight to FTTP will, & adding extra costs like increasing the node density and/or replacing much of the copper, does nothing to convince me that the Coalition’s plan is viable at all.
In an ideal telecommunications environment a decade ago VDSL would have made sense. To attempt to deploy VDSL2 in a degraded network, the projected budget & performance of the network will suffer to the extent that this folly will be remembered for generations as “when Australia’s telecommunications were set back a decade”. There will be no easy fix once upwards of 60 000 cabinets have been deployed, we will be stuck with a lemon that we will pay dearly for in decades to come.