In recent years, mobile communication networks have experienced significant evolution. The 3G mobile communication system, UMTS, employs WCDMA as the air interface standard, which leads to quite different mobile network planning and dimensioning processes compared with 2G systems. The UMTS system capacity is limited by the received interference at NodeBs due to
the unique features of WCDMA, which is denoted as `soft capacity'. Consequently, the key challenge in UMTS radio network planning has been shifted from channel allocation in the channelized 2G systems to blocking and outage probabilities computation under the `cell breathing' effects which are due to the relationship between network coverage and capacity. The interference characterization, especially for the other-cell interference, is one
of the most important components in 3G mobile networks planning.
This monograph firstly investigates the system behavior in the operation of UMTS uplink, and develops the analytic techniques
to model interference and system load as fully-characterized random variables, which can be directly applicable to the performance
modeling of such networks. When the analysis progresses from single-cell scenario to multi-cell scenario, as the target SIR
oriented power control mechanism is employed for maximum capacity, more sophisticated system operation, `feedback behavior', has
emerged, as the interference levels at different cells depend on each other. Such behaviors are also captured into the constructed interference model by iterative and approximation approaches.
The models are then extended to cater for the features of the newly introduced HSUPA, which provides enhanced dedicated channels
for the packet switched data services such that much higher bandwidth can be achieved for best-effort elastic traffic, which
allows network operators to cope with the coexistence of both circuit-switched and packet-switched traffic and guarantee the QoS
requirements. During the derivation, we consider various propagation models, traffic models, resource allocation schemes for many
possible scenarios, each of which may lead to different analytical models. All the suggested models are validated with either
Monte-Carlo simulations or discrete event simulations, where excellent matches between results are always achieved.
Furthermore, this monograph studies the optimization-based resource allocation strategies in the UMTS uplink with integrated
QoS/best-effort traffic. Optimization techniques, both linear-programming based and non-linear-programming based, are used
to determine how much resource should be assigned to each enhanced uplink user in the multi-cell environment where each NodeB possesses full knowledge of the whole network. The system performance under
such resource allocation schemes are analyzed and compared via Monte-Carlo simulations, which verifies that the proposed framework may serve as a good estimation and optimal reference to study how
systems perform for network operators.