[Background] Past & Future Mobile

watty

http://www.reghardware.co.uk/2009/07/14/future_wireless_tech/

8 pages

Very much from base Station vendor viewpoint, i.e. glosses over some important "gotchas"

But back in 2000, the mobile industry's self-delusion continued with the promise that 3G services would take the world by storm, and operators paid billions for some 2.1GHz spectrum in which to run 3G networks - their licences prevent them using the technology anywhere else. The 3G GSM standard is W-CDMA (Wideband Code Division Multiple Access) and offers much better data rates by taking advantage of a technology that was already popular in the US whereby multiple users can share the same frequency without mucking about with time slots.

CDMA is CHEAP. but breathes.

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 squeezing more speed made W-CDMA even more sensitive to Breathing and at 21Mbps, only one user is supported for the whole Cell-Sector, and only in < 5% of the area!

In the past, governments, through their regulatory bodies, awarded radio spectrum to groups who could most benefit the citizens governed, ensuring compatibility by mandating technologies and shifting radio spectrum around to provide competition where it was thought beneficial. More recently, governments have begun to see radio spectrum as a nice little earner

Misleading speed example

But LTE is more flexible than WiMax. It's able to operate in 1.25MHz increments of spectrum up to 20MHz - a bandwidth that can offer 160Mb/s downstream using two antennae, or more than 300Mb/s if you can squeeze in four aerials

These speeds are TOTAL PEAK Capacity for sector and only achievable close to a mast. More aerials adds serious costs (as it needs a shelf of electronics) and only increases nearby capacity, not peak user speed. The 160Mbps or 300Mbps translates to a 4Mbps to 5Mbps total throughput a virtual sector edge. Or about 1Mbps per person. Only just entry level Broadband.

... deployments will probably wait until some time around 2012.

Conclusion:
The future is LTE not WiMax.
... and for good voice coverage Operators may do better to keep GSM than switch to "breathing" W-CDMA based 3G with its unreliable coverage.

It will be 4 to 10 time better than 3G. But coverage and speed/capacity depends on Cell density. MIMO adds a lot of cost for extra capacity. More ROI by not deploying MIMO and simply having x2 to x4 slower speeds for same capacity. (peak speeds are the same, with or without MIMO).


Overall a fairly good article, though lacking the "gotchas".


The Mobile Industry still seems to suffer from delusions. They should make the top execs use HSPA and LTE modems exclusively on a economically loaded mast (for ROI) and then on a decent Fibre fed Cable and/or FTTC VDSL/ADSL-2 and then they might understand the difference between Mobile and Broadband.

The Mobile Operators should help companies put modems in Gadgets (money, subsidised operator sales etc). Play to their strength of Mobility, not compete with fixed Broadband.

Also we need a level palying field. LTE is NOT going to be cheap. But more expensive than GSM/3G as it the subsidy by voice can't continue. LTE is also VOIP only, it's not a telephone system with Data tacked on as GSM/3G is.