Posted on 08 March 2012.
4G mobile broadband and LTE explained
We now have a 4G-capable iPad. But what does 4G actually mean?
Today’s 3G/UMTS networks were only launched in 2003, providing the meagure mobile download speeds that many of us have to put up with today.
4G mobile broadband is its replacement, with deployment rapidly taking place in the US. However, Brits will be waiting a little while yet – read on for why.
All four major US operators now have 4G networks, with T-Mobile, AT&T, Verizon and AT&T now offering 4G mobile broadband alongside capable smartphones and tablets.
When will the UK get 4G?
The bad news is that ths UK is unlikely to get a sniff of a national 4G network in the UK any time soon.
Ofcom’s sale of spectrum that will carry the fourth generation licenses has been delayed until the second quarter of 2012.
The auction was originally intended to take place in the first three months of next year, but Ofcom has been unable to publish the terms of the auction due to disagreements with a number of networks.
Even if the auction takes place in the first half of 2012, we won’t see networks rolling the faster speeds out until 2013 at the earliest, putting the UK years behind some areas of the US and Japan.
“We are still aiming for the first half of next year. However, we have always maintained it is an ambitious timescale,” said an Ofcom spokesperson.
“This is a complex area, involving a large number of technical and competition issues that we need to consider and resolve before finalising proposals.
“For example, a very high proportion of households in the UK rely on Digital Terrestrial TV – Freeview – which needs to be relocated before 4G can be rolled out.”
Indeed, analysts at Informa Telecoms & Media have suggested that: “it is not economically viable to upgrade current UK mobile broadband networks to address traffic demands and improve user experience until 2015.”
But there have been trials. O2 has been testing LTE in Slough since 2009, where it achieved an impressive peak download speed of over 150Mbps.
Everything Everywhere and BT Wholesale started the first live trial of 4G LTE broadband in the UK last year, with Cornwall being used as the testbed for the next generation network. The trial used 10MHz of test 800MHz spectrum.
Everything Everywhere plans to roll-out 4G mobile internet for Orange and T-Mobile customers by the end of the year, providing it gets the green light from Ofcom.
The company has announced that a new 4G test on the 1800Mhz spectrum will commence in Bristol this April as part of its hopes to launch before the year is out.
In order to create the 4G network, it would be necessary for Ofcom to allow EE to convert some of its existing 1800Mhz spectrum license from 3G to 4G use. The regulator says it is considering the offer.
4G iPad band
The new iPad is designed to work across the spectrum band of 700-2100Mhz. While some trials in the UK have been outside this, the Everything Everwhere Bristol test will be within this.
4G download speeds
There are two standards that have been part of 4G – LTE and WiMAX, though LTE is now taking over as the dominant force.
4G would provide cited download speeds in excess of 100Mbps and upload rates over and above 50Mbps.
If these numbers eventually hold up (pinches of salt at the ready…), future LTE mobile devices could enjoy 5-6 times the performance of 3G with HSPA. In a Nokia trial, LTE set a cellular data record of 173Mbps in 2008. That’s seriously fast.
This dramatic speed boost comes courtesy of OFDM (Orthoganal Frequency Division Multiplexing), the same transmission technology used by ADSL, Wi-Fi, DVB-T, DVB-H and DAB. OFDM not only reduces latency, but minimises interference and can cram more data into the same slice of radio bandwidth. It will make LTE/4G phones ideal for streaming video and online gaming.
Because LTE is data-focused, not voice focused like 3G, it also employs the same TCP/IP protocols that underpin modern networking and Internet protocols. Once services begin to be deployed, voice traffic will be shifted from GSM to Voice over IP (VoIP), enabling your calls to be integrated with multimedia and web services.
Further speed increases are also possible with the addition of MIMO (Multiple Input Multiple Output) technology. The idea of having multiple antennas on transmitters and receivers is already used to great effect in 802.11n Wi-Fi gear.
Nokia’s 173Mbps trial used MIMO in a 2×2 configuration (ie two antennas on both the transmitter and receiver). A 4×4 MIMO setup could potentially deliver wireless 4G broadband speeds of 326.4 Mbps.
Of course, you’re unlikely to see anything like the maximum LTE data rate in practice. Peak speeds of around 25Mbps have been reported on Verizon’s 700MHz US network, with average speeds around half that figure. But that’s still about 3-4 times faster than current 3G connections. And the technology will get faster over time.
Sadly, we might have to wait a couple of years for LTE mobile phones to appear in the UK. But being late to the 4G party will have its advantages.
UK early adopters won’t face the crushing disappointment of buying poor hardware. So we won’t have to endure the 4G equivalent of the NEC e606. This early 3G hardware certainly deserves its place in history, but it was a god-awful phone.