UK Broadband is the UK’s largest commercial holder of radio spectrum suitable for 4G mobile services and fixed wireless solutions. At Mobile World Congress this year, the company announced it had turned on a trial network of TD-LTE in London’s Southwark area.
UK Broadband owns a seriously fat chunk of spectrum that can be used for 4G mobile services. In fact, it owns six 20 megahertz (MHz)channels of spectrum in the LTE bands 42 and 43, totalling 124 MHz of LTE spectrum, versus the one 20MHz channel each that the UK mobile operators will be able to own.
This company owns its big lumps of bandwidth in the 3.5 gigahertz (GHz) and 3.6GHz area, which was traditionally used for WiMax (UK mobile operators will own spectrum for FD-LTE in the 2.6MHz band, after the spectrum auction from the Digital Dividend). When LTE-Advanced was finalised by 3GPP in March 2011, that bandwidth was allowed to be used for LTE as well as WiMax, party because the WiMax operators out there have on the whole realised that WiMax is not going to be the next big mobile 4G technology, and therefore they need to reposition their companies onto the winning pony, LTE.
Popular and rich
That move, however, made UK Broadband instantly popular and potentially rich, and it is now turning its hand to providing mobile operators with wholesale TD-LTE network capacity for data services. Because significantly more mobile data is downloaded than uploaded, UK Broadband intends to use its fat TD-LTE pipe to provide mobile operators with a whitelabelled network that they can use to relive pressure on their LTE and 3G networks.
Nicholas James, UK Broadband’s CEO, states: 'Ofcom has stated that despite upcoming UK Digital Dividend spectrum auctions, capacity will run out soon, maybe within two years of the auctions, as data is expected to increase 25 times over the next five years. So, in the same way that people can drop of the mobile networks onto Wi-Fi today, in the future people will be dropped off onto our network. The difference is, when people drop off onto Wi-Fi today, operators ‘lose’ that customer, which is a big problem for operators. If a mobile operator drops a customer off onto our network though, we will be able to track that customer completely.'
UK Broadband has chosen to go with TD-LTE because you can use the same frequency for both upstream and downstream communications with the use of unpaired spectrum, unlike frequency division LTE (FD-LTE), which is about paired spectrum for bi-directional communications, with two paths for uplink and downlink open at the same time. FD-LTE, like TD-LTE, is good for voice conversations, but for data usage, FD-LTE will result in one band being jammed full while the other side is empty, versus TD-LTE, with which all bandwidth can be used to direct data traffic in whichever direction is required.
TD-LTE rocks for data
TD-LTE therefore allows UK Broadband to dynamically manage the network to maximise the download capacity at all times, optimising both the technology and the wide spectrum bands it has available to deliver a very high download capacity. TD-LTE is big in China, where it was invented, and it is already used in other parts of Asia and the US.
As for the trial, UK Broadband switched on its first 4G LTE system in London’s Southwark region on 29 February, making history as the first TD-LTE 3.5GHz deployment in the world, and the first commercial 4G deployment in the UK.
James explains: 'We are starting with the trial network in Southwark, and we will be building that out to other areas where we have identified opportunities. We are pitching all the cities in the UK to find anchor customers to get us in the door. We will build network based on those clients, and then roll the network out further according to demand.'
He continues: 'Because TD-LTE is IP, we can go to local government and offer them private high speed networks within our network; when they leave their office, they will leave the private network also. It’s very secure for the public sector, versus the mobile operator networks which are focused on connectivity for everyone, everywhere.'
The network is being built using Huawei’s TD-LTE solution, and is settling down before commercial launch in May this year. The first devices, jointly developed by UK Broadband and Huawei, include indoor and outdoor units for high speed wireless broadband to homes and businesses within the coverage area. Multi-mode mobile devices supporting TD-LTE, FD-LTE and 3G will be available from September 2012.
Mi-Fi not Wi-Fi
James notes: 'There are 1.5 million people in London alone who don’t have a fixed broadband connection at home; these people use 3G at the moment, but that doesn’t deliver the speeds they need. So, on 1 September the first device available for our network will be available, a Huawei home modem using Mi-Fi. With Mi-Fi, you can drive all your mobile devices, for LTE in our 3.5 and 3.6 frequency, the mobile operators’ 2.6 bandwidth, and 3G.'
James adds: 'In June 2013 the first Huawei smartphone including Mi-Fi will be launched. However, we do have other manufacturers looking at building other devices.'
The plan for the network, says James, is to work with partners to offer commercial services to businesses, consumers and the public sector. The network will be built out for partners on a demand basis, using the public sector and local government as anchor clients, from which other clients can be added to the network.