NBN Co will undertake construction trials in NSW and Queensland to test hooking up to the NBN homes that sit within the footprint of Optus's and Telstra's Hybrid Fibre Coaxial networks.
The trials will include hooking up homes that are not currently connected to the telcos' HFC networks.
The government-owned company said that the construction trials would begin mid-year.
The initial commercial release of HFC services on the NBN is slated for Q1 2016, according to the January 2015 edition of NBN Co's product roadmap.
The trials announced today will take place in the Sydney suburb of Emu Plains, and in Redcliffee, Slacks Creek and Merrimac in Queensland.
NBN Co late last year signed agreements with Telstra and Optus to progressively take ownership of the telcos' HFC networks.
Along with fibre-to-the-node and fibre-to-the-building, HFC is a key component of the Coalition government's revamped 'multi-technology mix' vision for the National Broadband Network.
In February, NBN Co announced it had signed a contract with ARRIS to provide equipment for the HFC component of the NBN.
ARRIS will upgrade the HFC networks to the latest cable broadband standard, DOCSIS 3.0.
NBN Co trials using DOCSIS 3.0 have achieved speeds of 376Mbps down and 49Mbps up.
In addition to hooking up new homes, the trials announced today will study "improving network capacity and broadband speeds consumers may receive," NBN Co's statement said.
NBN Co has said it is "considering" upgrading its HFC network to DOCSIS 3.1, the company's CFO Stephen Rue today told a hearing of the Senate's NBN committee.
DOCSIS 3.1 has in some trials been capable of gigabit speeds, NBN Co Bill Morrow said in February at a half-year results briefing for the company.
"The fact that we're going to be able to do this with our HFC network the fact that that HFC network is a far lower maintenance element than any of the other metallic-based, copper delivery services is good news for the consumer," he said during the briefing.
"The fact that we're getting this asset virtually for free from these two carriers means that that cost per premises element on this super-high-speed, easy to maintain, good product is going to be good for the taxpayer.
"So I don't think HFC has been understood well enough to realise how great this is for us, for the nation, and again for our overall budget of building out this network."