ks such as handovers will also have priority over normal data calls. The admission control will thus discrimi- nate between administrative tasks such as soft/softer HO, service calls and/ or emer- gency calls. Traffic levels representing the load of service request to a network will start the opera- tion of the admission control for management of congestion control and link quality management. Thus, in the following we briefly discuss the factors affecting load con- trol. 8.4.2.1 Load Control Analysis We measure traffic intensity generating a certain load in Erlangs. We can define the latter as the average number of simultaneous calls in a given period. For example, we can measure a series of calls lasting X seconds within 1 h in Erlangs, i.e.: calls x x s Erlangs (8.1) 3600 s If what we can measure of the generated traffic in a network is the carried load in Erlangs, then the offered load can be expressed as: carried_load offered load= (1 - blocking_rate) , (8.2) where the blocking rate refers to the measured blocking probability measure in a given BS. The blocking probability, or grade of service can be quantified through the Erlang- B formula, i.e. p° /C! Pblocking (8.3) where the C is the number of channels and p is the offered load. Based on the typical assumptions [19] for the offered traffic we can formulate the offered load as Resource and Network Management (8.4) where a is the Poisson arrival rate of a calls/s, and 1/u is the exponential call service time of (1/u) s/call. Notice that the logic applies mainly to CS calls; for data calls we need to use other distributions described in Chapter 2. Applying the blocking principle to the WCDMA we can now define soft blocking and hard blocking. Soft blocking assuming UL limitation can be defined from the following assumptions: perfect power control, each subscriber requiring the same E/No, constant number of users in the cell. However, none of the three assumptions will hold in practice specially with mixed services. Nevertheless, we use them here. Then, we ca