Channel type switching in WCDMA

Next generations mobilephone system WCDMA will provide wideband services. These services can be for example file transfers and use of WWW-browsers. Each user can be given two different types of traffic channels, a common channel to share with other users, or a dedicated channel, for one user only, with higher bandwidth. Channel type switching is the mechanism that chooses between these two channels. The purpose with this thesis was to study and develop a channel type switching algorithm, and then simulate and test it with different traffic cases. To implement such an algorithm, a prestudy first had to be made to find out what is important when dealing with channel type switching. All implementations and simulations were made in a network simulator called ns, developed by University of California at Berkely. Simulations show that the use of a timer together with thresholds for up and down switching, reduces the number of switches per second and user down to 40% of what it would be with only thresholds. This reduction saves valuable resources. Simulations also show that this combination of timer and thresholds is enough to have a well performing channel type switching algorithm.Validerat; 20101217 (root