Update: Telstra has released details of the new national wi-fi network. Click through to find out more.

Telstra will tomorrow announce the rollout of a national public wi-fi network in order to boost the amount of coverage available to customers of its broadband network.

The rollout is expected to cost tens of millions of dollars and will boost Telstra's existing geographic coverage of the majority of Australian homes and businesses even further, according to several reports.

Telstra declined to comment ahead of its planned announcement tomorrow.

The telco has previously trialled the use of heterogenous networks, or HetNets, in highly congested areas. The networks provide better interaction with existing fixed networks located nearby than similar "carrier on wheels" (COWS) technology.

HetNets use wi-fi to take pressure off of the cellular network. Telstra declined to comment on whether its wi-fi investment is part of a HetNet strategy.

Two years ago Telstra shut down its previous national network of wireless hot spots, which was available free to subscribers of its fixed iPhone plans or at 20c per minute for those not on an iPhone plan.

It shut down that service - which in 2005 contained around 400 hot spots - due to a lack of profit.

"Over time we've found that our customers prefer the convenience of taking their own internet connectivity with them through the use of mobile broadband," a spokesperson told iTnews at the time.

"This transition away from wireless hotspot usage has also been driven by the availability of fast 3G mobile coverage and more affordable data pricing."

At the time the telco said it planned to use its 4G network to accommodate growing user demand.