TABLE OF CONTENTS Why do we need 3G systems? Do we really need them? Could we do without them?
One much-quoted reason given to justify 3G is the lack of available channels in current 2G systems; especially in urban areas, the capacity limit of the existing 2G systems may be reached in the near future. During peak hours the operators may soon be unable to provide service for everybody in traffic hot spots. But the lack of capacity in 2G systems alone doesn't make the building of 3G systems necessary. Current 2G usage is still mostly voice, and this traffic could be handled quite easily by just adding extra frequency allocations to 2G networks (e.g., from the planned UMTS spectrum). One GSM frequency carrier takes 200-kHz bandwidth and can accommodate 8 traffic channels. Thus one WCDMA 5-MHz frequency carrier could accommodate 25 GSM frequency carriers translating into 200 GSM traffic channels. The true and practical number of traffic channels is lower, as control channels use part of the capacity. One does not really need the enormous 2-Mbps connections of 3G for voice; the 13-Kbps rate offered by GSM is quite enough for most applications.
We can see that the character of mobile communications will evolve considerably in the coming years, and data in their many forms will become more and more important. Voice will remain an important component in telecommunications, but quite often it will be combined with other types of information to form multimedia applications. The current 2G...
