Feeds

Cutting the cord: future mobile broadband tech

How internet on the go is going to get much faster

Business security measures using SSL

Each user's data, be it compressed voice or IP packets, is multiplied by what's called a 'spreading code' which is unique to that user. The receiving basestation gets the combined signals from every user on the frequency, but dividing that received data by the user's spreading code reproduces the original data for that specific user. Applying different spreading codes to the same received data can, in W-CDMA, reproduce the communication for almost 200 voice calls - depending on the codecs being used.

NEC 338 3G phone

Did anyone really make video calls?

Voice still takes precedence, but W-CDMA can support data rates of up to 384Kb/s with minimal connection times. Slower rates are also possible, as well as maintaining several connections at the same time. When 3G data services were developed, it was commonly thought that users would want multiple data connections billed at different rates: a slow connection for e-mail notifications might be free to use, a slightly-faster one for instant messaging could be always connected as part of a premium tariff, while the full 384Kb/s would be available on demand for video calling and the like.

But it's not just video calling that punters proved reluctant to do - not enough were downloading music from the network operators, or subscribing to video streaming services, or really using any of the whiz-bang services by which the operators had justified the billions spent on the licences. Unable to understand the reluctance of users the engineers decided that if only the connections were a little faster then the mobile internet would finally happen, so set about squeezing a little more speed out of the W-CDMA standard.

It's all in the angles - OFDM

OFDM (Orthogonal Frequency Division Multiplexing) isn't a new technique, or one unique to the cellular industry: it's also used by the Wi-Fi as well as ADSL broadband and DAB radio, but it is worth understanding as it provides remarkable facility as long as one has a wide enough band in which to use it.

The main problem OFDM solves is one of timing. A transmitter sends a chunk of data, followed by another one: assuming the chunks arrive sequentially then everything is fine, but if the first chunk bounces off a wall and thus arrives slightly later then it can interfere with the second one as their arrivals coincide. Obviously, this problem can be addressed by leaving a timing gap between the chunks, but OFDM instead puts them in different frequencies so the second can be sent immediately after the first.

That requires a fast radio and generally contiguous spectrum - though OFDM can be used in non-contiguous blocks, it's just more difficult. Orthogonal in this context means 'discrete' or 'separate' rather than anything to do with angles or Greeks.

New hybrid storage solutions

More from The Register

next story
4K-ing excellent TV is on its way ... in its own sweet time, natch
For decades Hollywood actually binned its 4K files. Doh!
Half a BILLION in the making: Bungie's Destiny reviewed
It feels very familiar - but it's still good
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
Apple's big bang: iPhone 6, ANOTHER iPhone 6 Plus and WATCH OUT
Let's >sigh< see what Cupertino has been up to for the past year
Huawei ditches new Windows Phone mobe plans, blames poor sales
Giganto mobe firm slams door shut on Microsoft. OH DEAR
Phones 4u website DIES as wounded mobe retailer struggles to stay above water
Founder blames 'ruthless network partners' for implosion
Get your Indian Landfill Android One handsets - they're only SIXTY QUID
Cheap and deafening mobes for the subcontinental masses
Apple's SNEAKY plan: COPY ANDROID. Hello iPhone 6, Watch
Sizes, prices and all – but not for the wrist-o-puter
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.
Security and trust: The backbone of doing business over the internet
Explores the current state of website security and the contributions Symantec is making to help organizations protect critical data and build trust with customers.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.