Telstra LTE versus Vividwireless LTE: what's the difference?

ARN breaks down the difference between the two LTE technologies

February is the month of Long Term Evolution (LTE) wireless broadband technology with both Telstra and Vividwireless announcing they will roll out 4G LTE networks across Australia.

But now LTE has been thrust into the limelight do most people have any idea what the technology does and what 4G means for them? How will it affect the telcos that are rolling out this technology?

Let's start with a disputed point. Can LTE be truly classed as 4G? Ericsson claims it can but a Huawei representative called LTE “3.9G” because it doesn’t quite meet the specifications of the 4G standard.

The International Telecommunications Union (ITU) recently said LTE may be classed as 4G as long as the technology gave a "substantial level of improvement in performance capabilities with respect to the initial third generation systems deployed".

First major fact: While Telstra and Vividwireless both claim to be deploying 4G LTE, they are using two different types of technology.

Telstra has gone with Freqency Division Duplex LTE (FD-LTE) while Vivid is using Time Division Duplex LTE (TD-LTE).

Telstra said its LTE areas can expect download speeds of more than 20Mbps but the telco could not give a definite on what final theoretical speeds will be. It confirmed it was using FD-LTE technology from Ericsson for the network upgrade.

Ericsson said speeds achieved through its FD-LTE systems can be much higher than 20Mbps (based on examples around the world) but, again, could not disclose exactly what speeds Telstra customers can expect.

Meanwhile, Vividwireless is touting its TD-LTE can deliver 40-70Mbps download speeds and 4-7Mbps for upstream.

Chinese vendor, Huawei, is supplying the TD-LTE equipment.

Both service providers are using LTE technology but what is the difference between FD-LTE and TD-LTE? And should we care?

In terms of underlying technology, there really isn’t much difference between FD and TD. The key point of differentiation is the way it carries data across a given spectrum. FD operates on paired spectrums while TD uses unpaired spectrums.

To put it simply, FD-LTE requires two frequencies to facilitate two-way communication (download and upload) while TD-LTE only requires one channel.

While the latter is the newer version of LTE, its predecessor is the more popular choice as telcos usually carry paired spectrums readily - used for 2G and 3G networks - that can be reused. This saves telcos money on acquiring new spectrums.

This is exactly what Telstra has done. It is refarming its 1800MHz spectrum, used for 2G services, for its LTE network.

“Operators decide to launch FD or TD-LTE based on spectrum availability, that is, what spectrum they have on hand,” Ericsson strategic marketing manager, Warren Chaisatien, said. “Most of Telstra’s customer base consists of 3G customers so the 2G spectrum has a very light network load.”

Optus and Vodafone Hutchinson Australia (VHA) are expected to follow suit and implement FD-LTE systems.

But are these telcos missing out by deploying an older form of LTE?

Putting the issue of purchasing spectrums aside, the cost of rolling out either of those two technologies is comparable. There are just minor hardware differences, according to Huawei.

However, a key advantage of TD-LTE is the ability to customise download and upload speeds.

“You can set the TD-LTE system to suit the actual application that is being used for,” Huawei wireless marketing manager, Terry Walsh. “For example, if you want to upload more data, you can set a higher upload ratio to download.”

Not only that, but TD-LTE is backwards compatible with WiMax. This means WiMax operators can quickly and easily upgrade their networks to LTE.

Walsh conceded the technology’s performance is slightly inferior with that of FD-LTE. But the difference is negligible as both technologies are spectrally efficient.

While FD-LTE is deems a more popular choice among telcos, TD-LTE is on the rise. Walsh expects vendors to start producing more FD and TD-LTE compatible devices in the future as both technologies come to the fore.

Be it FD or TD, LTE is finally coming into play in the Australian telecommunications space. While rollout for Telstra and Vividwireless’ 4G networks aren’t going to be ready for the next 12-18 months, expect LTE to dominate telco industry discussions as competitors begin jumping on the bandwagon.