4G and LTE: everything you need to know

Australia's largest telco was the first to jump on the LTE train, launching its first services in October 2011.

Initially only available to customers who purchased 4G dongles on 24 month contracts, the network immediately impressed pundits across the country for its speed.

At launch, the Telstra LTE network used the 1800MHz spectrum. Previously, this network was used to transmit 2G services, but with the rise of 3G-enabled devices, demand for 2G dropped enough that Telstra was able to repurpose the network for 4G.

That said, Telstra has since expanded its LTE network significantly, using the 900MHz frequency and launching its 700MHz network under the moniker 4GX.

Telstra claims its LTE network delivers download speeds between 2Mbps and 40Mbps, while upload speeds between 1Mbps and 10Mbps. In the real world, those lofty numbers will elude you, although we've regularly experienced speeds upwards of 20Mbps.

In Perth, where Telstra has access to a bit more spectrum, the telco rolled out 20MHz services that promised even faster speeds for late 2013.

Speaking of coverage, Telstra makes a big deal out of the fact its LTE network already hit its target of about 85 per cent by Christmas 2013.

Telstra also had Australia's first Category 4 (Cat 4) LTE device available from mid-2013. Since then, the telco has been powering through those LTE Categories, and in September launched Australia's first Cat 11 device.

Cat 11 LTE can theoretically push download speed up to 600Mbps. Technically the first Cat 11 device in the world, Telstra's WiFi 4GX Advanced III Mobile Broadband Hotspot features three band carrier aggregation, for much faster download speeds.

Those speeds are only available in capital cities on the eastern seaboard of Australia, and only via the hotspot device, although undoubtedly we'll see phones offering support for Cat 11 in the not too distant future.

Digital dividends

On the 1st of January 2015, Telstra turned on its 700MHz frequency and rebranded its 4G offering to 4GX. The 700MHz frequency was purchased in 2013 at the Digital Dividend auction where the AMCA sold off old analogue TV frequencies. As the lowest mobile carrier frequency it is particularly good at penetrating buildings and, as such, has been mostly allocated to city centres.

Telstra has big plans for 4G network development, with the company trialling Skinet for in-flight LTE data use, as well as bringing LTE-Broadcast online.

In October, Telstra successfully showcased its LTE Broadcast technology at the NRL grand final. Users at the event were able to access three streams of the match via a dedicated app, including watching the match live, instant replays and a dedicated stat channel.

Telstra has committed to trying to make LTE-B commercially viable within the next 12 months, although we're not sure when or how the rollout will proceed.

The telco has also performed significant testing on Voice over LTE (VoLTE) which uses 4G to deliver voice calls, thus reducing the total data consumed and speeding up calls.

In September 2015 the network officially launched VoLTE. Only a handful of devices currently support VoLTE, but that will grow as Telstra expands the service in the coming months.