To pick one simple aspect
- WCDMA is designed for 5MHz (as GSM already is 200kHz)
- QCDMA is designed for 1MHz (as AMPS-TDMA were 30kHz
and spectrum is a pain with a great cavalry criss-cross riding on the waves)
-GSM can use the "guardbands" lost in QCDMA, not
to forget the overlapping, problematic, inter-operator,
GPS synchronized nyquist-slopes.
That is
- WCDMA does not gain from 5 to 10Mhz
- QCDMA claims to gain by that extra 1MHz carrier
- GSM gains from any transition from 200kHZ up to
any MHz compared to the two above, no CDMA-style
losses from medium or fast power control, not restricted
by the 64 walsh code channels,etc,etc, almost as optimal as
OFDMA. (when synchronized, exactly the same, but then not
robust anymore)
Bw, did anyone understand my example on 10,000
teenagers arriving at rock-festival (or fat
middle managers at a golf conference), the need
to keep track of all their inactive handsets??
And then to activate some to transfer that little
SMS message, WAP page??
How much power control cell capacity is needed to send
160 bytes, how much shannon capacity is wasted
just to get that handset up and going?? (zero for GSM,
although the delay goes higher than the regular 1s)
Ilmarinen
In contrast to Seybold, these are the things that operators
have learned to understand. |
