e, capacity and quality of the network. Streaming Class Multimedia, video on demand, etc., are examples of the streaming class. The data are transferred in a steady and continuous stream. How does this work? On the Internet, the display starts even when the entire file has not been downloaded. The delay in this class is higher than the conversational class. Interactive Class The Internet is a classical example of the interactive class. The subscriber requests the information from the server and waits for the information to arrive. Thus, delay is not the ster minimum under this class as the time to download also depends upon the number of subscribers logged on to the system and the system capacity itself. Another aspect of this service is that the transfer of data is transparent. Location based services and computer games are other examples of this class of service. Background Class Other applications such as SMS, fax, emails, etc., fall under the background class. Delay is the highest in this class of service. Also, the data transfer is not transparent as in the interactive class. 1.4.3 HSDPA in UMTS High Speed Downlink Packet Access (HSDPA) is a packet based data service in the downlink having a transmission rate up to 8-10 Mbps over the 5 MHz bandwidth. This means that implementation of this technique will allow data speeds to increase to almost five times that of the most advanced Wideband Code Division Multiple Access (WCDMA) networks. Also, the base station capacity increased Third Generation Cellular Networks by double. The system capacity and the user data rates are increased by implementation of HSDPA, which includes MIMO (Multiple Input Multiple Output), cell search, advanced receiver design, HARQ (Hybrid Automatic Request) and AMC (Adaptive Modulation and Coding). HSDPA is mainly intended for non- real-time traffic, but can also be used for traffic with tighter delay requirements (for more details refer to Appendix B). Radio Network Planning and Optimisation Johanna Kähkönen, Nezha Larhrissi, Cameron Gi