Wireless company UK Broadband has switched on a wholesale 4G network in the London Borough of Southwark, offering high-speed services for the public sector and big corporations, as well as providing backhaul for mobile networks.

The network has been built using Huawei’s Time Division Long Term Evolution (TD-LTE) solution. TD-LTE is a variant of the LTE wireless standard, developed by China Mobile specifically to meet the growing demand for data capacity.

Unlike Frequency-Division Long-Term Evolution (FD-LTE), which carries two separate signals – one for uploading and one for downloading – TD-LTE uses a single channel, and dynamically assigns bandwidth to each connection based on user requirements. This means that download capacity is maximised at all times.

UK Broadband's chief executive Nicholas James explained that this is important because nine times more data is downloaded than uploaded. With FD-LTE, as much as 40 percent of the spectrum will be empty when the downlink is full, but TD-LTE can flex according to usage, so there is no wasted spectrum.

Despite this, most of the UK's mobile operators will be bidding for FD-LTE in the forthcoming 4G spectrum auction, because they are concerned about preserving their voice market as well as building a data market. James explained that the job of UK Broadband would be to provide a solid platform for operators to drop onto when capacity on their own networks becomes constrained.

“The amount of data is expected to increase 25 times over the next five years. Ofcom has predicted that, even after the 4G spectrum, the UK's mobile operators will only have enough to last them a couple of years before their networks are full again,” said James

“The increase in traffic isn't just because individuals are going to use 25 times more data; it is because there will be lots of other uses for that data. Machine-to-machine (M2M), traffic lights, CCTV, e-health, mobile working for council workers – all these kinds of things are not being served at all in the mobile world at the moment, but once the technology is available you're going to see huge growth.”

UK Broadband’s 4G network will be delivered over six 20MHz channels of spectrum in the 3.5GHz and 3.6GHz bands, which became part of the LTE standard in March 2011. The company said that this would allow it to deliver LTE-Advanced speeds and enough capacity to deliver Next Generation Access superfast broadband speeds to a large number of users simultaneously.

In the forthcoming 4G auction, none of the UK operators will get more than one 20MHz LTE channel, so James believes that UK Broadband’s 4G network will be in high demand.

“Nobody can solve the problem on their own. We're all going to need to find ways of moving customers around our networks, so wherever they are, they can drop off to whatever capacity is there,” said James. “Today the operators drop you off onto Wi-Fi quite a lot, and they'll continue to do that, but they'll also drop off onto our network, and indeed any other network that's available.

“The customer doesn't really care how they get the service. The future is about this seamless handover,” he added.

The first device, jointly developed by UK Broadband and Huawei, is a home hub that provides broadband by wireless. That will be followed by a “MiFi” device in September, that allows the user to connect up to seven devices by Wi-Fi at once, with 4G connection speeds. This will support 2.6GHz, as well as 3G, FD-LTE and TD-LTE.

James explained that mobile handsets will take longer to come to market, because of the complexity of incorporating all these different standards. However, Huawei demonstrated a prototype of the first smartphone to support TD-LTE at Mobile World Congress, which will be available in June 2013.

Earlier this year, ABI Research predicted that at least half a million base stations will be installed or upgraded for the TD-LTE standard by the end of 2016. The company said that many WiMAX operators are now looking to upgrade to TD-LTE rather than WiMAX 2 – which was developed to provide higher data rates and increased capacity.