Feeds

Faster mobile data: the road to 4G

Better LTE than never

  • alert
  • submit to reddit

Choosing a cloud hosting partner with confidence

Feature

The great thing about standards, as some wit once said, is that there are so many to choose from. Mobile phones are afflicted worse than most technology – a multiplicity of standards, nested within one another like a messy set of Russian dolls filled with alphabet soup.

The 'generations' of mobile networks are fairly loose, but appear roughly once a decade: the first, analogue, 1G cellular networks around 1981, then digital 2G in about 1992. The latest is 4G, but its not as clear cut a step ahead of its predecessors as they were to theirs.

Generic mast

Source: Karl Baron

At the turn of the century, 3G was formally defined to mean data speeds of at least 200Kb/s by the International Telecommunication Union's IMT (International Mobile Telecommunications) 2000 specification. However, IMT -2000 didn't specify the "air interface" – the radio link from phone, tablet or modem to mast – so two competing standards developed out of the two prevailing 2G systems.

GSM, as used by about 85 per cent of the world, yielded UMTS (Universal Mobile Telecommunications System). UMTS uses the W-CDMA (Wideband Code Division Multiple Access) air interface. It's the form of 3G we in the UK are used to.

The battle for the air interface

In America, Qualcomm upgraded its CMDMA technology to create CDMA 2000. It's used in the US and parts of Asia, predominantly South Korea. CDMA 2000 devices don't work on UMTS networks and vice versa, although both are 3G because that moniker dictates how fast they can move data, not the technology they use to do it.

Likewise, 4G is primarily a speed requirement. The successor to the ITU's IMT 2000 specification is IMT Advanced and was defined in 2008. It stipulates that 4G should deliver data speeds to users of around 100Mb/s if they are moving, rising to 1Gb/s if they're standing still.

LTE FDD and TDD

LTE now comes in two flavours: FDD (Frequency Division Duplex) and TDD (Time Division Duplex)
Source: Qualcomm

Existing mobile networks have two, parallel infrastructures: one, circuit-switched, for voice calls, and a separate, packet-switched layer for data traffic. 4G is a pure packet-switched TCP/IP network, running everything over IPv6. Voice becomes just another data type.

By the time the ITU defined IMT Advanced, two competing systems were already under development, each formed from the two 3G systems. A group called 3GPP (3G Partnership Project) developed LTE (Long Term Evolution), a successor to UMTS. Meanwhile, the totally separate 3GPP2 was working on UMB (Ultra Mobile Broadband), an upgrade to Qualcomm's CDMA2000.

Website security in corporate America

More from The Register

next story
Man buys iPHONE 6 and DROPS IT to SMASH on PURPOSE
Yarrrgh! 'Tis Antipodean insanity, ye crazy swab
Oi, Tim Cook. Apple Watch. I DARE you to tell me, IN PERSON, that it's secure
State attorney demands Apple CEO bows the knee to him
4K-ing excellent TV is on its way ... in its own sweet time, natch
For decades Hollywood actually binned its 4K files. Doh!
Your chance to WIN the WORLD'S ONLY HANDHELD ZX SPECTRUM
Reg staff not allowed to enter, god dammit
Phones 4u website DIES as wounded mobe retailer struggles to stay above water
Founder blames 'ruthless network partners' for implosion
Monitors monitor's monitoring finds touch screens have 0.4% market share
Not four. Point four. Count yer booty again, Microsoft
DARPA-backed jetpack prototype built to make soldiers run faster
4 Minute Mile project hatched to speed up tired troops
prev story

Whitepapers

Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.
WIN a very cool portable ZX Spectrum
Win a one-off portable Spectrum built by legendary hardware hacker Ben Heck
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Beginner's guide to SSL certificates
De-mystify the technology involved and give you the information you need to make the best decision when considering your online security options.