 BSs to reach the same mobile's Eb/No requirement while we combine the paths. We separate the information signal of different users by assigning to each one a differ- ent broadband and time limited, user specific carrier signal derived from orthogonal code sequences (e.g. OVSF codes). When completely orthogonal4, we can perfectly separate synchronously transmitted and received signals. However, this does not occur in the UL for example, due to different propagation paths, i.e. different distances with different time delays. In the DL even if all signals originate from a single point and the parallel code channels can be synchronized there is still not perfect signal separation. As a result, we cannot maintain complete orthogonality due to multipath propagation, and we have to use orthogonality compensation factors as noted in Chapter 2. PARAMETERS FOR MULTISERVICE TRAFFIC While some earlier5 2G mobile systems measure network quality mainly for one ser- vice, e.g. speech, UMTS has many different bearer services with varying quality re- quirements. We characterize these differing services by parameters such as the bit rate, the maximal delay, connection symmetry, and tolerable maximum BER. As result to accurately dimension or design a network for multiple services, we need to use different traffic models and settings. We have to plan the BS numbers to handle the expected service mix. The multiple set of services will have different impact on capacity and coverage. For example, user bit rate will have large impact on coverage as illustrated in 1 Interference = intracell interference and intercell interference. 2 Interference here implies intracell interference and intercell interference. Softer handover is a soft handover between two sectors of a site. Two function orthogonality, e.g. g(t) and s(t), occurs when their cross-correlation functions equal zero. 5 Today GSM evolved to a more than just speech network, it does also GPRS and HSCSD. The UMTS Network and Radio Access Technology Figure 7.2. On the other hand, w