Στόχος της διπλωματικής αυτής είναι η παρουσίαση τεχνικών στα πλαίσια της Διαχείρισης Ραδιοπόρων με σκοπό την βελτιστοποίηση της παρεχόμενης υπηρεσίας (QoS), σε δίκτυα κινητής τηλεφωνίας 3ης γενιάς. Στο πρώτο κεφάλαιο γίνεται μια εισαγωγή στα δίκτυα κινητών επικοινωνιών και μια ιστορική αναδρομή. Στη συνέχεια παρουσιάζεται μια επισκόπηση της τεχνολογίας του CDMA και γίνεται καταγραφή και ανάλυση τεχνικών RRM. Στο σύστημα UMTS είναι αφιερωμένο ολόκληρο το δεύτερο κεφάλαιο. Το UMTS εξετάζεται από πλευράς αρχιτεκτονικής και πρωτοκόλλων. Το handover ως βασικό στοιχείο της Διαχείρισης Ραδιοπόρων μελετάται στο τρίτο κεφάλαιο. Ιδιαίτερη αναφορά και μελέτη γίνεται για το Soft Handover, ως το βασικό Handover του συστήματος WCDMA, που χρησιμοποιείται προκειμένου να διασφαλιστεί η απαιτούμενη υπηρεσία. Στο τέταρτο κεφάλαιο περνάμε στην multicast μετάδοση. Σε αυτή την περίπτωση εξετάζουμε την αποδοτική επιλογή καναλιού (Efficient Channel Selection), με στόχο την διασφάλιση του ίδιου QoS για όσο το δυνατόν περισσότερους χρήστες κάνοντας την καλύτερη δυνατή διαχείριση των πόρων του συστήματος. Τέλος το πέμπτο κεφάλαιο αφιερώνεται στην συνολική παρουσίαση των συμπερασμάτων που έχουν εξαχθεί στα προηγούμενα κεφάλαια. / -

Ο στόχος αυτής της διπλωματικής ήταν να μελετηθεί και να κατανοηθεί ο τρόπος λειτουργίας των WCDMA ασύρματων δικτύων καθώς και να υπολογιστεί η χωρητικότητα μιας κυψέλης κινητής τηλεφωνίας 3ης γενιάς. Αυτό επιτυγχάνεται μέσω του υπολογισμού των πιθανοτήτων απώλειας κλήσεων (CBP), στην κατερχόμενη ζεύξη (downlink). Δηλαδή στην περίπτωση που το σήμα αποστέλλεται από το σταθμό βάσης στον συνδρομητή. Ο υπολογισμός των πιθανοτήτων απώλειας κλήσεων είναι απαραίτητος στα WCDMA δίκτυα για τον σωστό υπολογισμό της χωρητικότητας (σε erlang) και του network dimensioning. Το αναλυτικό μοντέλο που χρησιμοποιούμαι λαμβάνει υπ’ όψιν του τα εξής: multi-service περιβάλλον, soft blocking, imperfect power control καθώς και την πολυόδευση. Τα αποτελέσματα του αναλυτικού μοντέλου συγκρίνονται μέσω προσομοίωσης και είναι αρκετά ικανοποιητικά. Τέλος εξετάζουμε και την επίδραση του orthogonality factor στην χωρητικότητα του δικτύου. / In WCDMA networks, the Call Blocking Probability (CBP) assessment is necessary for proper cell capacity determination, in respect of traffic load in erlangs, and network dimensioning. This paper focuses on the downlink capacity estimation, through CBP calculation in a WCDMA cell. To this end, we construct an analytical model for the WCDMA cell by taking into consideration the effects of the following: the multi-service environment, soft blocking, imperfect power control and multipath propagation. To analyze the system, we describe the WCDMA cell by a Markov chain, where each system state represents a certain number of resources occupied by the mobile users. We solve the Markov state and provide an efficient recurrent formula for the system occupancy distribution, as well as the so-called local blocking probabilities. Based on them, we calculate the CBP of different service-classes accommodated in the cell versus the total offered traffic load. The WCDMA cell capacity in erlangs is determined by the maximum traffic load which satisfies certain CBP (CBP boundary) per service-class. We evaluate the analytical model through simulation. The results show that the accuracy of the model is very satisfactory. In addition, we show the effect of the intra-cell interference (due to orthogonality factor) on the erlang capacity of the cell.

The evolvement of the uplink in the third generation mobile telecommunication system is an ongoing process. The Enhanced Uplink (EUL) concept is being developed to meet the expected need from more advanced services, like video streaming and mobile broadband. One idea for further improvement in the EUL concept is to introduce Time Division Multiple Access (TDMA), which is studied in this master thesis. The master thesis assignment is to study the consequences of introducing TDMA in EUL. The goal has been to identify the gains and problems, and how they can be handled. A derived theoretical framework and system simulations, using a radio network simulator, are used. The overall conclusion is that there is a potentially large gain with an introduction of TDMA in EUL. Simulations in favorable conditions have shown that the system throughput can increase by 100% when there are only User Equipment (UE) that are using EUL in the system and by 50% when there is a mix of speech and EUL UE’s. When using TDMA the uplink load also shows improvements, the mean is generally higher but the variance is generally smaller. Due to major differences in experienced interference between passive and active UE’s, the signal quality will vary a lot. The big variation in signal quality is identified as the main problem with introducing TDMA in EUL. It is shown that this problem can generate extreme high uplink load, which have a negative impact both on the resource efficiency and the coverage.

Due to terminal mobility and change of service area, efficient IP mobility support is an important aspect in UMTS networks in order to provide mobile users negligible packet loss rate and low handover latency, and thus some level of guaranteed quality-ofservice (QoS) to support real-time applications. 3G/UMTS has been specified and implemented as an end-to-end mobile communications system. The underlying WCDMA access systems manage radio access handover (layer 1) and provide linklayer mobility (layer 2) in terms of connection setup and resource management. For the UMTS nodes to have seamless connectivity with the Internet, the UMTS core networks need to be able to support continuous and no network service session handover (layer 3 and above). A long IP handover latency results in high packet loss rate and severely degrades its end-to-end transport level performance. Network-layer handover latency has therefore been regarded as one of the fundamental limitations in IP-based UMTS networks. Therefore, it is crucial to provide efficient network-layer mobility management in UMTS/WCDMA networks for seamless end-to-end TCP connection with the global Internet. Mobility of UMTS nodes necessitates extra functionalities such as user location tracking, address registration and handover related mechanisms. The challenge to provide seamless mobility in UMTS requires localised location management and efficient IP handover management. Mobile IPv6 protocol offers a better mobility support as the extended IPv6 features with mobility mechanism are integrated to the mobile nodes. To mitigate the effect of lengthy IP handover latency, two well-known handover reducing mechanisms based on Mobile IPv6 support have been proposed in the literature. They are designed with hierarchical network management and address pre-configuration mechanism. Hierarchical management aims to reduce the network registration time, and fast-handover attempts to minimise the address resolution delay. S-MIP (Seamless Mobile IP) integrates the key benefits of the above IP mobility mechanisms coupled with local retransmission scheme to achieve packet lossless and extremely low handover latency, operating in WLAN environments. In this thesis, we explore the possible Mobile IP solutions and various IP handover optimisation schemes in IPv6 to provide seamless mobility in UMTS with the global Internet. It aims at developing an optimised handover scheme that encompasses the packet lossless and extremely low handover latency scheme in S-MIP, and applying it into the UMTS/WCDMA packet data domain. Therefore, the hybrid UMTS-SMIP architecture is able to meet the requirements of delay sensitive real-time applications requiring strict delay bound, packet lossless and low handover latency performance for end-to-end TCP connection during a UMTS IP-based handover. The overall seamless handover architecture in UMTS facilitates integrated, scalable and flexible global IP handover solution enabling new services, assuring service quality and meeting the user???s expectations in future all-IP UMTS deployment. The viability of the seamless mobility scheme in UMTS is reflected through and validated in our design model, network protocol implementation, and service architecture. We illustrate the performance gained in QoS parameters, as a result of converged UMTS-SMIP framework compared to other Mobile IPv6 variants. The simulation results show such a viable and promising seamless handover scheme in UMTS on IP handover latency reduction on its end-to-end TCP connection.

To save time in Flextronics high volume production, the time for test and calibration of mobile telephones need to be as short and accurate as possible. In the wideband code division multiple access (WCDMA) case, the output power calibration is the most critical calibration concerning accuracy. The aim with this thesis was to find a faster calibration method than the one that exists today and still retain accuracy. The Third Generation Partnership Project (3GPP) outlines the requirements of the output power and they must be thoroughly considered when choosing calibration method. Measurement accuracy and the behavior of the transmitter chain parameters also must be considered. The output power in the WCDMA phone studied is controlled by seven parameters. The parameters are characterized in this thesis, and are found to be too hardware dependent to be predicted or to be seen as predictions from each other. Since no parameter predictions are possible it was stated that all parameters have to be measured, and a new way of measuring them in a faster way is proposed. The principle of the new measurement method is presented, and the implemented software is tested and evaluated. The new method mainly makes use of the spectrum analyzer zero span function. The evaluation shows that the new method is faster than the original and retains accuracy. The measurement uncertainties even seem to diminish, which implicates decreased temperature dependence due to faster measurement time.

This report looks at the modern cellular wireless network environment and the factors of energy consumption therein. The consumption of connectivity re- lated hardware is gradually becoming a larger part of the power consumption of virtually any mobile device. This report studies measurements of a mobile broadband module energy usage due to data transfer. It is found that switch- ing between technologies is still beneficial and savings are very feasible when using technologies with different traits if done correctly. Further the possibility of energy savings within a single high-bandwidth technology (3G) are assessed considering variations on response time and throughput. This is relevant as the need to handle highly dynamic loads becomes more and more important in the modern connectivity landscape. By gauging the savings available from schedul- ing link accesses and switching technology this is put in context by sampling a few common services namely Skype, Spotify and normal web browsing for their energy footprints. We will also look briefly at the background traffic generated by two common operating systems, Windows 7 and Ubuntu GNU/Linux.

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The development of 3G (the 3rd generation telecommunication) value-added services brings higher requirements of Quality of Service (QoS). Wideband Code Division Multiple Access (WCDMA) is one of three 3G standards, and enhancement of QoS for WCDMA Core Network (CN) becomes more and more important for users and carriers. The dissertation focuses on enhancement of QoS for WCDMA CN. The purpose is to realize the DiffServ (Differentiated Services) model of QoS for WCDMA CN. Based on the parallelism characteristic of Network Processors (NPs), the NP programming model is classified as Pool of Threads (POTs) and Hyper Task Chaining (HTC). In this study, an integrated programming model that combines both of the two models was designed. This model has highly efficient and flexible features, and also solves the problems of sharing conflicts and packet ordering. We used this model as the programming model to realize DiffServ QoS for WCDMA CN. The realization mechanism of the DiffServ model mainly consists of buffer management, packet scheduling and packet classification algorithms based on NPs. First, we proposed an adaptive buffer management algorithm called Packet Adaptive Fair Dropping (PAFD), which takes into consideration of both fairness and throughput, and has smooth service curves. Then, an improved packet scheduling algorithm called Priority-based Weighted Fair Queuing (PWFQ) was introduced to ensure the fairness of packet scheduling and reduce queue time of data packets. At the same time, the delay and jitter are also maintained in a small range. Thirdly, a multi-dimensional packet classification algorithm called Classification Based on Network Processors (CBNPs) was designed. It effectively reduces the memory access and storage space, and provides less time and space complexity. Lastly, an integrated hardware and software system of the DiffServ model of QoS for WCDMA CN was proposed. It was implemented on the NP IXP2400. According to the corresponding experiment results, the proposed system significantly enhanced QoS for WCDMA CN. It extensively improves consistent response time, display distortion and sound image synchronization, and thus increases network efficiency and saves network resource.

A local call admission control (CAC) algorithm for third generation wireless networks was designed and implemented, which allows for the simulation of network throughput for different spreading factors and various mobility scenarios. A global CAC algorithm is also implemented and used as a benchmark since it is inherently optimized; it yields the best possible performance but has an intensive computational complexity. Optimized local CAC algorithm achieves similar performance as global CAC algorithm at a fraction of the computational cost. Design of a dynamic channel assignment algorithm for IEEE 802.11 wireless systems is also presented. Channels are assigned dynamically depending on the minimal interference generated by the neighboring access points on a reference access point. Analysis of dynamic channel assignment algorithm shows an improvement by a factor of 4 over the default settings of having all access points use the same channel, resulting significantly higher network throughput.

The content of this work is focused on the methods of multiple access for terrestrial radio network. These methods are exploited by the systems second and third generation of mobile networks. Specification the basic characteristics these methods is responsible part for inquest the correspondent specificities. Reason is that, that the wireless mobile communication it is possible split by three generation. First is NMT, with analog frequency modulation, which dont make use already, because has considerable disavantages . Analysis second generation mobile systems GSM leads to determination to many advanta- ges hereof system, who be based on methods FDMA, TDMA, CDMA. Description these methods is specialized on their spreading properties. Third generation of mobile systems UMTS is characterized wideband technology WCDMA, making use two duplex methods (FDD, TDD). Both methods provide higher efficiency of recovery frequency spectrum . All the theoretical approaches are examined in the last part of this work.it´s then possible after complete analysis these methods, make a design and a realization. In this event was used the computer programme Matlab–Simulink for simula- tion of duplex method WCDMA-FDD. Evaluation of this technology provides confrontation with second generation GSM .