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A concern-based approach to support software comprehension and analysis is proposed. Concerns represent various aspects of a system, like features, architectural solutions, units of work, etc., which are interesting for some stakeholders. Using concern-based queries on the software artefacts, new derived information on the system can be exposed. The results of the queries are also represented as concerns and added to the concern repository. The approach thus supports the analyzer in gradually building up an understanding on the subject system to be analyzed.

The third-generation cellular systems will offer services with higher bit rates compared to today's networks and therefore for an operator it is of the utmost importance to exploit all possible resources to improve the capacity of the radio network. One attractive possibility, already used in most of the second-generation networks, is to increase the sectorisation at the base stations, i.e., using 3 or even up to 6 sectors per site. In this paper we demonstrate with simulations and some theoretical derivation how the sectorisation of the base stations influences the performance (capacity and quality of service) of a WCDMA radio network. In addition the simulator and the modelling of the third generation's fast power control and soft handover are presented.

A diversity handover simulator using measured propagation data is introduced. Furthermore, three different diversity handover algorithms are compared and the comparison results are introduced in this paper. The algorithms used in the study were the basic cdmaOne algorithm, modified cdmaOne algorithm and an algorithm with a threshold relative to the strongest received pilot channel Ec/Io. The most stable performance in terms of diversity handover (DHO) probability can be achieved with the slope algorithm. The basic cdmaOne algorithm tends to be very sensitive to the interference situation. The algorithm, which makes the decision based on the relative differences of the received pilot Ec/Io levels, rather than on absolute thresholds, shows moderate change in both the active set update period and in the DHO probability in changing interference conditions.

The third-generation cellular systems will offer services well beyond the capabilities of today's networks. For an operator to provide the maximum capacity of the network supporting multiple traffic mixes more advanced analysis methods are required. The scope of this paper is to demonstrate with simulations how the subscriber profile (mobile station speed and the used service) impact on the network capacity and quality of service. Furthermore, the simulator used in the study is described, the uplink and downlink iterations and the fast power control and soft handover modeling are briefly introduced.

The scope of this paper is to demonstrate the impact of the soft handover on the WCDMA network performance. The gains from the selection combining and increased diversity in uplink soft handover of a WCDMA system have been studied with the help of link level simulations. Two base stations have been included in the simulation model. The average required transmitted and received E/sub b//I/sub 0/ ensuring the desired quality has been measured as a function of the level difference between the two base stations. This has been done for two multipath propagation channels and several mobile station (MS) speeds. In addition, the paper discusses how the soft handover reduces the required power control headroom near the cell edge.

A static radio network simulator for studying various topics of 3rd generation WCDMA radio network planning is presented. The simulator allows analyzing coverage, capacity and quality of service related issues. Input to the simulator is the network scenario and the user information as a mobile station map. The uplink and downlink are separately analyzed and the outputs are presented in form of maps of best server, number of users, served traffic, SHO areas, AS size, SHO statistics for the area and for the users, Perch C/I plots. In the analysis, impact of the 3rd generations fast power control and soft(er) handover (SHO) possibility are taken into account by importing link level simulations into the analyses. The whole simulator is entirely based on Matlab(R) software.

The paper evaluates experimentally the most important parameters of the two-dimensional (2D) propagation environment. For this purpose, measurements with both fixed and rotating base station (BS) antenna arrays were performed. With a fixed array installation, environmental parameters, such as effective side lobe level (ESL) and cross polarisation discrimination (XPD) were evaluated. With the rotating BS antenna path angular spread (PAS), total angular spread values and the two-dimensional channel impulse responses (2D-CIR) were recorded. Two BS sites were used. With the measured data a simple beam pointing algorithm was tested and the number of receiving beams needed in different measured locations for optimum reception was estimated. With the measured 2D data simple 2D-RAKE allocation routines were done related to a CDMA-SDMA application.

In 3/sup rd/ generation cellular systems using WCDMA radio access technology (RAT) one operator could theoretically operate it's network by using only one frequency when another operator in the same area uses the immediate adjacent frequency. Then, on contrary to other systems, the adjacent channel interference (ACI) is coming entirely from another operator. Since most likely the network plans will be completely independent, the only means to combat this ACI is applying appropriate filters. This paper shows results on a study of the influence of 2 macro operators using WCDMA RAT in the same area in adjacent channels, by applying the filter values specified in 3GPP TS 25.101and 3GPP TS 25.104 . Two cases, one from an urban and one from a suburban area are shown. Example results on outage, coverage probabilities, quality of service, transmit power distributions etc. are presented with and without the second operator present and compared with each other. In conclusion of the comparison it is shown, that in macro cellular scenarios the influence of both operators on each other is negligible.

A simple method is derived for estimating the downlink capacity and required base station transmission power in a WCDMA system. This is based on a downlink pole equation which is mostly similar with the well known CDMA uplink pole equation. It is shown that the total downlink transmission power is composed of two terms. The first term is equal to what would be needed in the absence of interference and the second one shows the increase due to multiple access interference which is inversely proportional to 1-/spl eta//sub DL/ where /spl eta//sub DL/ is called the downlink loading. The method can be used in radio network dimensioning where extensive simulations can not be run. Usage of the method is demonstrated by some examples.

The 3/sup rd/ generation cellular systems will offer services with higher bit rates compared to today's networks and therefore for an operator it is of utmost importance to exploit all possible resources to improve the capacity and quality of service of the radio network. The scope of this paper is to demonstrate with simulations how careful radio network planning can improve the network capacity and quality of service (QoS). Furthermore, it is demonstrated how the site configuration expansions can support the network capacity growth. Example results of omni-, three-, four- and six sectored site configuration simulations are presented including four different antennas and various different tilts. Furthermore a test case is shown to demonstrate the effect of a mast head amplifier (MHA) in the WCDMA uplink.

The third generation cellular systems will offer services well beyond the capabilities of today's networks. For an operator to optimise their business cases accurate methods are required for the capacity and coverage estimation. The scope of this paper is to concentrate on the first phase of the radio network planning process: radio network dimensioning. Dimensioning is providing the first rough estimate of the radio network's capabilities in terms of capacity, coverage and quality. In this work the radio network dimensioning rules and methods are introduced. Furthermore, the proposed methods are verified with radio network simulations. It has been demonstrated that the proposed methods work reasonable well even with relatively high bit rates. In addition to that it is shown that in case of WCDMA macrocell dimensioning it is not adequate to base the results on uplink only.