11.3 3.5G HSDPA/HSUPA
The voice service and SMS were the driving force of cellular networks development until recently. However, nowadays this trend is changing. There is a huge demand among subscribers for high-speed data services. Operators are also trying to offer data services to improve ARPU (Average Revenue Per User) and hence profitability. With the help of the high-speed data services operators can offer consumers video on demand, television, streaming music, as well as the ability to record and send short movies. For business users, the most interesting feature is the high speed Internet access from a laptop or mobile phone anywhere, which very often is not possible to do via WiFi connection, since a WiFi coverage is very fragmentary. As can be seen from Tables 11.4 and 11.5, Release’99 channels are able in principle to provide the data rates both in uplink and downlink up to 2 Mbits/s. However, in real life the data rate for Release’99 WCDMA usually is about 384 Kbits/s for downlink and 128 Kbits/s for uplink and the typical round trip delay for packet data is about 120 – 200 ms. The high-speed data service is characterized by the fact that typically data arrives in bursts, which poses the problem of fast changing need in radio resources. Moreover, the low delays are required for many services (for example, for video). The Release’99 WCDMA is not capable of meeting all these requirements. The real answer for the high-speed data services demand was the Release 5 of 3GPP ...
