This is in contrast to other DSL services which are delivered over a copper pair that remains connected into the Telstra network and provides the standard telephone service. The customer can take this service form Telstra, the ISP providing the DSL service or another service provider but the phone service, at least from the Telstra exchange is delivered over the Telstra network.
This service known as line sharing or spectrum sharing and is made possible by some of the frequencies of signals on the copper pair being used for voice and come for DSL services - that's why you need those little filters on your phone line, to separate the voice and the DSL signals. Use of spectrum sharing does not significantly reduce the bandwidth available from the DSL service.
Both technologies are well established and have been in use in the Australian network for several years serving many thousands of homes and businesses. So any kind of technology trial is unnecessary.
If you look at the page on Telstra's web site (which I believe is its only public information on the trial so far) You would think it was offering a 'new and better' service: called ADSL2+. Here is what it says.
You can read more stories on telecommunications in our newsletter ExchangeDaily, click here to sign up for a free trial...