<p>The traditional voice service in mobile networks is an important service that mobile users expect high quality from. With the convergence of mobile networks towards an all-IP network, an IP-based speech service becomes important which is referred to as Voice-over-IP (VoIP). The traditional voice service is highly optimized and a VoIP service must therefore fulfil strict quality requirements to provide the same speech service quality. The air interface technology, WCDMA, which is used in third generation communication systems in Europe is constantly developed. An improved concept for the mobile-to-network transmission, called the Enhanced Uplink (EUL) provides for higher uplink capacity for packet data services. It also includes features that may provide a sufficient VoIP service quality in mobile networks, when considering the uplink transmission. </p><p>The purpose of this thesis is to evaluate the VoIP capacity over EUL and identify crucial aspects of radio resource management in order to increase the capacity. This is done through dynamic system simulations, using a realistic VoIP traffic model. The VoIP capacity is also estimated by a derived theoretical framework.\newline </p><p>It is shown by simulation results and theoretical estimations, that power control is a vital mechanism in order to increase the capacity. Simulation results indicate that a VoIP over EUL capacity of 65\% of the traditional voice service capacity may be reached. The results also indicate that to improve the capacity for larger cells, the allowed VoIP packet delay must be increased.</p>

The traditional voice service in mobile networks is an important service that mobile users expect high quality from. With the convergence of mobile networks towards an all-IP network, an IP-based speech service becomes important which is referred to as Voice-over-IP (VoIP). The traditional voice service is highly optimized and a VoIP service must therefore fulfil strict quality requirements to provide the same speech service quality. The air interface technology, WCDMA, which is used in third generation communication systems in Europe is constantly developed. An improved concept for the mobile-to-network transmission, called the Enhanced Uplink (EUL) provides for higher uplink capacity for packet data services. It also includes features that may provide a sufficient VoIP service quality in mobile networks, when considering the uplink transmission. The purpose of this thesis is to evaluate the VoIP capacity over EUL and identify crucial aspects of radio resource management in order to increase the capacity. This is done through dynamic system simulations, using a realistic VoIP traffic model. The VoIP capacity is also estimated by a derived theoretical framework.\newline It is shown by simulation results and theoretical estimations, that power control is a vital mechanism in order to increase the capacity. Simulation results indicate that a VoIP over EUL capacity of 65\% of the traditional voice service capacity may be reached. The results also indicate that to improve the capacity for larger cells, the allowed VoIP packet delay must be increased.

<p>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.</p><p>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.</p><p>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.</p><p>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.</p>

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.

<p>The increasing use of data services and the importance of IP basedservices in third generation mobile communication system (3G), requires the transmission from the cell phone to the base station, i.e. uplink, to manage high speed data rates. In the air interface for 3G in Europe, WCDMA, a concept for enhancing the transmission from the cell phone to the base station, called Enhanced Uplink, is being standardized. The overall goal is to provide high speed data access for the uplink. One of the requirements is that the enhanced uplink channels must be able to coexist with already existing WCDMA releases. For example, the enhanced uplink must not impact seriously on real time services, such as speech, carried on current WCDMA channels.</p><p>The purpose of this work is to study how the quality, coverage and capacity of real time services carried on previous WCDMA releases is affected when introducing the Enhanced Uplink in a WCDMA network. The main focus of the study is thus to demonstrate the trade-off between voice and best effort performances.</p><p>Theoretical assessments and simulations show that the Enhanced Uplink has many advantages over previous WCDMA releases. For example the Enhanced Uplink yields a larger system throughput for all voice loads. The noise rise, i.e. the ratio of total received power to the background noise power is being considered as the resource. It is shown that user traffic carried on the Enhanced Uplink is able to operate under a higher noise rise level as well as to get a higher throughput per noise rise. The resource is hence more efficiently utilized.</p>

The increasing use of data services and the importance of IP basedservices in third generation mobile communication system (3G), requires the transmission from the cell phone to the base station, i.e. uplink, to manage high speed data rates. In the air interface for 3G in Europe, WCDMA, a concept for enhancing the transmission from the cell phone to the base station, called Enhanced Uplink, is being standardized. The overall goal is to provide high speed data access for the uplink. One of the requirements is that the enhanced uplink channels must be able to coexist with already existing WCDMA releases. For example, the enhanced uplink must not impact seriously on real time services, such as speech, carried on current WCDMA channels. The purpose of this work is to study how the quality, coverage and capacity of real time services carried on previous WCDMA releases is affected when introducing the Enhanced Uplink in a WCDMA network. The main focus of the study is thus to demonstrate the trade-off between voice and best effort performances. Theoretical assessments and simulations show that the Enhanced Uplink has many advantages over previous WCDMA releases. For example the Enhanced Uplink yields a larger system throughput for all voice loads. The noise rise, i.e. the ratio of total received power to the background noise power is being considered as the resource. It is shown that user traffic carried on the Enhanced Uplink is able to operate under a higher noise rise level as well as to get a higher throughput per noise rise. The resource is hence more efficiently utilized.

The uplink load for the scheduling of Enhanced-Uplink (E-UL) channels determine the achievable data rate for Wideband Code Division Multiple Access (WCDMA) systems, therefore its accurate measurement carries a prime significance. The uplink load also known as Rise-over-Thermal (RoT), which is the quotient of the Received Total Wideband Power (RTWP) and the Thermal Noise Power floor. It is a major parameter which is calculated at each Transmission Time Interval (TTI) for maintaining cell coverage and stability. The RoT algorithm for evaluation of uplink load is considered as a complex and resource demanding among several Radio Resource Management (RRM) algorithms running in a radio system. The main focus of this thesis is to study RoT algorithm presently deployed in radio units and its possible optimization by reducing complexity of the algorithm in terms of memory usage and processing power. The calculation of RoT comprises three main blocks a Kalman filter, a noise floor estimator and the RoT computation. After analyzing the complexity of each block it has been established that the noise floor estimator block is consuming most of the processing power producing peak processor load since it involves many complex floating point calculations. However, the other blocks do not affect the processing load significantly. It was also observed that some block updates can be reduced in order to decrease the average load on the processor. Three techniques are proposed for reducing the complexity of the RoT algorithm, two for the reduction of peak load and one for the reduction of average load. For reducing the peak load, an interpolation approach is used instead of performing transcendental mathematical calculations. Also, the calculations involving noise floor estimation are extended over several TTIs by keeping in view that the estimation is not time critical. For the reduction of average load, the update rate for the Kalman Filter block is reduced. Based on these optimization steps, a modified algorithm for RoT computation with reduced complexity is proposed. The proposed changes are tested by means of MATLAB simulations demonstrating the improved performance with consistency in the output results. Finally, an arithmetic operation count is done using the hardware manual of Power PC (PPC405) used in Platform 4, which gives a rough estimate of decrease in the percentage of calculations after optimization. / saabairshad@gmail.com