NBN are considering implementing G.Fast technology in to their fibre-copper “multi-technology” mix for Australia’s next-generation broadband network. This is in addition to VDSL2 for “fibre-to-the-node” and “fibre-to-the-building” , fibre-to-the-premises and HFC coaxial deployments for fixed-line setups.
But what is G.Fast?
G.Fast is a DSL-based broadband technology that uses phone wires. Yet it has a faster throughput than VDSL2 that is currently used for fibre-copper setups. Here, the local copper loop between the customer’s premises and the DSLAM can be less than 500 metres for a 100Mbps link speed but can achieve a link speed of 1.3Gbps for a 70-metre loop.
It is capable of symmetrical operation which can please business deployments where a lot of data is uploaded as part of cloud computing and remote storage requirements.
Where would an infrastructure provider deploy this technology?
This would be deployed to a “fibre-to-the-distribution-point” setup where the fibre-copper interface is a distribution box that covers a residential street or block and any cul-de-sacs that run off that street, or a small strip of shops typically this side of 50 premises.
Similarly, most multi-tenancy units like apartment blocks or shopping centres would benefit from this kind of technology for their fibre-copper needs.
But there is a setup that appeals to the infrastructure providers where they could service a single premises by having fibre to the pole or pit outside the premises and using the telephone cabling to provide the copper link. This has a strong appeal when it comes to a “self-provisioned” Gigabit service where the service provider doesn’t have to interact with landlords or schedule installation appointments with householders to get the household on board.
There is the appeal that the technology can allow the DSLAM to be “reverse powered” – powered by the customer’s modem router or a power-injector that the customer installs at their premises.
One major current problem with deploying G.Fast, especially in a self-install setup is that, at the moment, there isn’t much support for this technology as far as customer-premises equipment is concerned. Most likely, this will be rectified as more countries roll out G.Fast deployments and manufacturers offer DSL modem routers that support G.Fast alongside VDSL2 and ADSL2; and this will initially appeal to carriers and service providers who want to provide the equipment rather than have customers buy their own equipment.
NBN’s trial deployment
NBN ran their first trial in a Melbourne office building which was wired up with 20-year-old Category 3 cabling and provided with a VDSL2 “fibre-to-the-node” service. But they nailed a throughput of 600Mbps with the VDSL2 service operating and found that they could achieve 800Mbps in that same development without VDSL2 running.
They realised that they would need to complete more trials in conjunction with the retail ISPs who are using this infrastructure through 2016. This is more to test the waters with different operating environments and to identify whether it is the technology that can be used.
As an infrastructure provider, they were drawn to the G.Fast concept due to the idea of providing Gigabit service to most urban premises on a self-install basis rather than messing with truck rolls, landlords and owners corporations.
The burning question that will come across NBN deploying G.Fast is knowing whether the wiring at the consumer premises is up to the task for transferring high-speed data. It is because of the fact that there are older deployments that may be victims to poor connections including wiring short-cuts that may hamper the throughput needed for today’s needs.