On Fri, Nov 22, 2002 at 02:57:53PM +0800, Tony Chan wrote:
>
> if CDMA2000 is 3G than WCDMA is 4G. Think of it this way, GSM uses a 250
> khz carrier, CDMA uses a 1.25Mhz carrier, WCDMA uses a 5 MHz carrier -
> hence wideband.
You're giving the width of frequency bands; the carrier is just the
basis for a band.
<snip>
> the point is that while CDMA is mature now and starting to evolve more
> rapidly as a technology with 1x, and 1x EV-Dx, it is still limited by
> its 1.25MHz carrier design. There is only so much bandwidth that you can
> pack into a 1.25MHz carrier (so far about 2.4 Mbps with EV-DV). With its
> bigger carrier, WCDMA networks will always be capable of 3x the
> throughput of CDMA. All those performance improvements, like 1x, and
> EV-Dx, will eventually be develop for WCDMA, so when the technical
> improvements of EV-DV is deployed over a WCDMA network it should get
> something like 7.2 Mbps.
The wider the band, the fewer bands there can be within the frequency
range allocated to the network. So I don't see why the total capacity
of a cell or network should differ much, depending on whether it uses
1.25 MHz or 5 MHz bands. Using wider bands does allow a higher bit
rate for individual connections, but I'd be very surprised if there's
going to be enough overall capacity to provide multi-Mbps connections
to anyone.
<snip>
> analysts who say that operators with 3G licenses should forget about
> WCDMA because it is late and just built a CDMA 1x, or worse GSM 1x
> network in its place, obvious don't understand anything about the Asian
> market or the difference between GSM and CDMA.
<snip>
It seems to me that the sensible upgrade is to something that's
compatible (in terms of hand-off and so on) with the 2G network - so
from GSM/GPRS the upgrade path is to UMTS (using WCDMA), whereas from
CDMAone the path is to CDMA 1x.
--
Ben Hutchings | personal web site: http://womble.decadentplace.org.uk/
Beware of bugs in the above code;
I have only proved it correct, not tried it. - Donald Knuth
Received on Fri Nov 22 14:17:39 2002