Telstra claims its 4G (also known as long-term evolution or LTE) network is twice as fast as its existing 3G. Download speeds on 4G can range from 2Mbps to 40Mbps, whereas the current 3G network is 1.1Mbps to 20Mbps.

Foad Fadaghi, telecommunications analyst at Telsyte, said: "Carriers are likely to have similar premium pricing on their 4G/LTE service, with 3G services becoming cheaper and commoditised."

Retail sources visiting the Consumer Electronics Show in Las Vegas told this website that Telstra would begin selling the 4G device in late January, but an exact date had yet to be locked down.

A separate source confirmed this timeframe and said the handset in question would be the HTC Velocity.

Telstra would not confirm the date but said: “We know there's a huge appetite for 4G-powered smartphones in Australia. We're working with some of the world's leading manufacturers - including HTC - to bring some of these devices to customers in the first half of 2012.”

Telstra, which began selling a 4G wireless broadband dongle late last year, has previously said it would launch its first 4G smartphone in Australia in the first half of this year but it is understood that it has now decided to launch the device as early as possible - between January 20 and the end of the month.

The source would not give specifics about the handset but this morning Gizmodo published leaked marketing material for the HTC Velocity that it said was created by Telstra for the upcoming launch.

The marketing reveals the phone will have a dual-core 1.5GHz processor, a 4.5-inch HD screen, 16GB of onboard storage with a microSD expansion slot and an 8MP camera that can shoot 1080p video.

The phone appears to be a version of the HTC Raider 4G handset that was launched overseas in October last year.

The device will be the first in a line of 4G phones and tablets released by Telstra.

Several 4G devices were launched at CES this week, including the Nokia Lumia 900 and HTC Titan 2 Windows Phone 7 handsets, the Samsung Galaxy Note LTE and the Sony Xperia Ion.

Many of the 4G phones available overseas need to be modified before they will work on Australian networks, which operate at a different frequency. Telstra's 4G network runs on the 1800MHz band.

Optus has said it plans to switch on its 4G mobile network in Newcastle in April this year, followed by Sydney, Melbourne and Perth by the middle of the year and Adelaide and Brisbane sometime after that.

Vodafone has been conducting 4G LTE trials and upgrading its base stations with the new technology but has not said when it would officially switch on the network.

Asher Moses travelled to Las Vegas as a guest of Samsung.