Quote:
Originally Posted by inquisitor
You seem not to know a basic difference between GSM and UMTS: While in GSM-networks neighbouring cells must use different channels to avoid interferences and so the " Four color theorem" must be observed, in UMTS all cells use the same frequency. So 2 x 5 MHz (5 MHz for the uplink and 5 MHz for the downlink) is enough for a continious network. Of course you can add additional capacity by running a second UMTS-carrier on separate 2 x 5 MHz-channels.
In Germany all the 4 active operators have just 2 x 10 MHz in the 2100 MHz-band. |
Yes, but the use of a single channel increases the noise floor and reduces the system capacity and data rate. Which is why I said "2nd rate". With GSM systems, cochannel interference will really mess things up. With CDMA it slowly degrades the system. A cumulative effect. UMTS-TDD avoids this problem by time-slicing everything.