 it is the 'network' that does not work and gets the whole blame. Transmission Capacity It is equally possible that signalling does work properly, but there is not enough bandwidth in the transmission links for user traffic channel allocation, thus causing accessibility problems. Since the environment is SO complex in the radio interface and transmission interfaces of 3G networks, admission control algorithms are used to calculate whether the agreed service quality is met for all ongoing services if a new service request is accepted. Based on that calculation the new service request is either accepted or rejected. This means that the system is calculating all the time what is the load of the network. This is the reason why TDMA and CDMA networks in radio interface and circuit switched and packet switched networks in transmission interfaces differ SO fundamentally. There are no specifications an how exactly admission control algorithms should do that calculation and it is more than likely that each vendor has his/her own way of doing it. This means that for end users to find the transmission capacity and its possible congestion they will have to use the specific algorithm from the vendor. Creating an algorithm that is fast, trouble-free, guarantees the quality and is capacity-friendly is not actually a very easy task, and depending on which optimisation approach that vendor has chosen surprisingly different results can be calculated using the same input values. Being fast and trouble-free are fundamental requirements for the admission control algorithm. How- ever, if guaranteeing quality is the main approach the algorithm easily becomes a glutton for capacity or if saving in capacity is the main approach then the algorithm is to a certain extent jeopardising the quality of services. Finding the golden mean is the challenge. Looking back to quality and end user perception from the transmission capacity viewpoint, if a service request by the end user is rejected by the admission control algorithm that will translate