Although considerable effort has been placed on developing techniques and algo rithms to create feasible cell plans, much less effort has been placed on understanding the relationship between variables and objectives. The purpose of this thesis is to improve the body of knowledge aimed at understanding the trade-offs and tensions in the selection of transmission sites and in the configuration of macro-cells for GSM and related FDMA wireless systems. The work begins by using an abstract 2-dimensional (2D) model for area coverage. A multiple objective optimisation framework is de veloped to optimise the sequential placement and configuration of downlink wireless cells. This is deployed using a range of evolutionary algorithms whose performance is compared. The framework is further tuned via a decoding mechanisms using the best performing evolutionary algorithm. The relationship between primary variables in the 2D model is analysed in detail. To improve realism, the thesis additionally addresses complexities relating to planning in 3-dimensional (3D) environments. A detailed open source static model is developed and the optimisation framework is extended to accommodate the additional model complexities and choices in algorithm design are compared. Finally, sensitivity analysis is performed to determine the relationship between objectives in the 3D model and benchmark solutions are provided.

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This thesis addresses the transmission of video over third generation radio access networks. The first part of the thesis investigates the capabilities of Universal Terrestrial Radio Access Networks (UTRAN) in terms of the provision of multimedia communications. The error performance and traffic requirements of real-time video transmission over circuit switched and packet switched connections are examined. The effect of network parameter settings upon video performances is evaluated, and optimum radio bearer configurations for the transmission of video are derived. A method of estimating received video quality after transmission over error prone environments is developed. The quality estimation is based on a distortion model, which accurately models the overall distortion seen in decoder frame reconstruction. This includes quantisation distortion, concealment distortion, and error propagation. Based on the developed performance model, optimum MTU (Maximum Transfer Unit) size for efficient wireless video communications over a packet switched access network is derived. The second part of the thesis investigates quality enhancement techniques for multimedia traffic transmitted over wireless channels. Quality enhancement is achieved at three levels of the transmission process: link level, application level and system level. Link level quality enhancement techniques are designed to optimise the allocation of link level parameter values according to the media characteristics. A novel Unequal Error Protection scheme and a novel Unequal Power Allocation scheme are designed to exploit the inherent diversity in the subjective importance of different sections of compressed media. The algorithms are developed and analysed for transmission of video over 3G wireless systems. The effectiveness of these algorithms is demonstrated through the results of simulated transmission over a UMTS channel. Application level quality enhancement techniques are designed to explore the time-varying nature of the wireless channel. A number of link adaptation schemes are proposed for real time video communication and real-time video streaming over 3G wireless systems. These algorithms are designed to enhance the perceptual video quality, and the system utilisation. This is achieved by adapting the allocated radio network parameters and the source parameters, according to a feedback channel condition. Simulation results show a significant performance improvement compared to non-adaptive schemes. Finally, system level adaptation techniques are designed for efficient radio resource allocation in multi-user scenarios. Two adaptive resource allocation schemes are proposed and analysed for real-time video communications in a UMTS system. The proposed algorithms are shown to provide improved performances in terms of average received video quality and user satisfaction. Key words: Wireless Communication, Multimedia communication. Video Transmission.

Soft handover is one of the most important functionalities for radio resource management in CDMA based wireless cellular systems. It is used in the intra-frequency handover and allows mobile stations to be connected simultaneously to several base stations, which are selected by a defined soft handover algorithm. Soft handover provides signal diversity in both uplink and downlink, leading to improvements to the quality of service. Proper design of soft handover is one of the main challenges in Wideband CDMA based third generation mobile systems such as UMTS, as it has a great impact on the trade-offs between coverage, system capacity and service quality in the network. However, soft handover control in UMTS suffers from inflexibility and inefficiency due to its pre-determined parameters and isolated operational manner, while the wireless radio networks are fully dynamic in terms of geographical as well as interference variations. The principal objective of this research therefore is to comprehensively understand soft handover implications on the system performance and hence to develop adaptive and flexible and yet robust soft handover control mechanisms for UMTS. The research work concentrates first on understanding the impacts of soft handover on the system performances of sectored and hierarchical cellular systems. The complexities of soft handover behaviours resulted from various handover related factors as well as the shadowing correlation are then studied. Based on the above investigations, three enhanced soft handover algorithms finally are proposed for UMTS. Compared to conventional UMTS soft handover algorithm, the proposed algorithms significantly improve the overall system performances and achieve better trade-offs between the quality of service, radio resource utilization and network costs. Key words: Soft Handover, Wideband CDMA, Radio Resource Management, UMTS.

WCDMA was proposed as the candidate air interface for the global 3G standard, however it will exist in three main modes of operation; the MC-CDMA to be employed in America based on the commercial IS-95 standard, with TDD, and FDD mode in Asia, and Europe. ETSI was the main European standardisation player for the evolution of the UMTS system, but activities were then passed on to the 3rd Generation Partnership Project group, which have released several versions of the standard, the latest being "Release6". Now, we are entering the early deployment phase, where recent field trials suggest that up to 384 kb/s throughput can be reasonable expected from UMTS in vehicular environments. The first round of downlink receivers will be based on the RAKE architecture, that requires advanced estimation techniques to overcome the adverse effects of the channel. In this thesis, we investigate several channel estimation techniques based on classical, and Bayesian estimation theory. We conclude that not one filter can operate satisfactorily under all channel conditions, thus providing impetus for investigating hybrid estimation schemes based on the joint application of linear interpolation with Kalman filtering. Normalised LMS algorithm, and raised cosine interpolation. In the domain of delay estimation, the MUSIC estimator performance was investigated and compared with the traditional sliding correlator filter. It was concluded that the MUSIC can provide an additional dimension in performance by overcoming the near-far effect. The main target was to address signal subspace tracking techniques to track the time-varying statistics of the channel. We concluded that the MUSIC algorithm in unison with the Minimum Description Length function, and the PASTd algorithm can provide robust performance over the required operating range. We refer to this solution as the "Adaptive MUSIC estimator". In the last chapter, we address the joint application of the raised cosine interpolation filter with the Adaptive MUSIC estimator on RAKE receiver performance. It was concluded that these two schemes could be a practical solution to the estimation problem for the first batch of UMTS receivers. In unison they provide a comprehensive solution in terms of robust estimation in low SNR environments and over the required mobile velocity range, blind detection, low complexity, and adaptivity to a time-varying channel environment.

Code Division Multiple Access (CDMA) has been selected as the main technology for third generation (3G) mobile communication system. Traffic expectations of 3G are high whilst only limited spectrum is available. Any system enhancement that would increase capacity and improve spectral efficiency is highly desired. Power control is the single most important requirement of any CDMA based mobile communication system. Power control directly impacts the quality of service as well as system capacity. It is for this particular reason that adaptive power control schemes have been the subject of many researchers in recent years. In this thesis, a novel Environment Detection Algorithm (EDA), an essential component of adaptive communication systems is presented and extensively evaluated. EDA is an important enabling component of Speed Adapted Closed Loop Power Control (SA-CLPC). An advanced SA-CLPC is presented and its superiority in both terrestrial and satellite communication systems is clearly demonstrated. The work follows to introduce a novel interference management technique in the form of a distributed power control algorithm. The proposed algorithm outperforms all its rivals by maximising C/I in response to system load without the need to any knowledge of users in the neighbouring cells. Key words: CDMA, Power Control, Speed Estimation, Open Loop Power Control, Closed Loop Power Control, Adaptive Power Control, Environment Detection Algorithm, Delay Spread Estimation, Distributed Power Control, centralised Power Control.

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This thesis presents an analysis of the relationship that exists between the use of place-specific information in mobile communication technologies and the different aspects of place-making and self-presentation in London. Through a study of empirical data collected from seven focus groups, during which a total of 38 participants were asked to draw sketch maps of London to shed light on social and spatial interactions in the urban space related to the proliferation of mobile communication technologies and their location-aware features. To this end, the development of locative media within specific types of location-aware mobile devices and services is shown to be intimately interrelated with different aspects of place-making and self-presentation in London. This thesis demonstrates that mobile and locative media serves as a platform through which the user can communicate different aspects of themselves and their relationship with specific places, while also constructing a sense of those places by sharing individual narratives of their everyday lives. Highlighting the significance of sharing and retrieving locational information through mobile and locative media, this study not only analyses the use of mobile and locative media in everyday life, but reflects also on how the perception of places is transformed as a result of social and spatial interactions, and the practices of sharing and remembering, as well as navigating. Employing a holistic approach in the framing and research of locative media, and introducing sketch-mapping as a creative methodology in the form of focus groups for a research into communication and media, this thesis makes an original contribution to existing literature, especially in the field of mobile and locative media.

The world around us is getting more connected with each day passing by – new portable devices employing wireless connections to various networks wherever one might be. Locationaware computing has become an important bit of telecommunication services and industry. For this reason, the research efforts on new and improved localisation algorithms are constantly being performed. Thus far, the satellite positioning systems have achieved highest popularity and penetration regarding the global position estimation. In spite the numerous investigations aimed at enabling these systems to equally procure the position in both indoor and outdoor environments, this is still a task to be completed. This research work presented herein aimed at improving the state-of-the-art positioning techniques through the use of two highly popular mobile communication systems: WLAN and public land mobile networks. These systems already have widely deployed network structures (coverage) and a vast number of (inexpensive) mobile clients, so using them for additional, positioning purposes is rational and logical. First, the positioning in WLAN systems was analysed and elaborated. The indoor test-bed, used for verifying the models’ performances, covered almost 10,000m2 area. It has been chosen carefully so that the positioning could be thoroughly explored. The measurement campaigns performed therein covered the whole of test-bed environment and gave insight into location dependent parameters available in WLAN networks. Further analysis of the data lead to developing of positioning models based on ANNs. The best single ANN model obtained 9.26m average distance error and 7.75m median distance error. The novel positioning model structure, consisting of cascade-connected ANNs, improved those results to 8.14m and 4.57m, respectively. To adequately compare the proposed techniques with other, well-known research techniques, the environment positioning error parameter was introduced. This parameter enables to take the size of the test environment into account when comparing the accuracy of the indoor positioning techniques. Concerning the PLMN positioning, in-depth analysis of available system parameters and signalling protocols produced a positioning algorithm, capable of fusing the system received signal strength parameters received from multiple systems and multiple operators. Knowing that most of the areas are covered by signals from more than one network operator and even more than one system from one operator, it becomes easy to note the great practical value of this novel algorithm. On the other hand, an extensive drive-test measurement campaign, covering more than 600km in the central areas of Belgrade, was performed. Using this algorithm and applying the single ANN models to the recorded measurements, a 59m average distance error and 50m median distance error were obtained. Moreover, the positioning in indoor environment was verified and the degradation of performances, due to the crossenvironment model use, was reported: 105m average distance error and 101m median distance error. When applying the new, cascade-connected ANN structure model, distance errors were reduced to 26m and 2m, for the average and median distance errors, respectively. The obtained positioning accuracy was shown to be good enough for the implementation of a broad scope of location based services by using the existing and deployed, commonly available, infrastructure.

It has been envisaged that in future 5G networks user devices will become an integral part of the network by participating in the transmission of mobile content traffic typically through Device-to-device (D2D) technologies. In this context, we promote the concept of Mobility as a Service (MaaS), where the mobile network edge is equipped with necessary knowledge on device mobility in order to meet specific service requirements for clients via a small number of helper devices. In this thesis, we propose a MaaS paradigm based frameworks to address clients’ requirement with regards to content offloading service and connectivity relaying service via network assisted D2D communication framework. To address content traffic offloading, we present a device-level Information Centric Networking (ICN) architecture that is able to perform intelligent content distribution operations according to necessary context information on mobile user mobility and content characteristics. Based on such an architecture, we further introduce device-level online content caching and offline helper selection algorithms in order to optimise the overall system efficiency. In particular, this piece of work sheds distinct light on the importance of user mobility data analytics based on which helper selection can lead to overall system optimality. Based on representative user mobility models, we conducted realistic simulation experiments and modelling which have proven the efficiency in terms of both network traffic offloading gains and user-oriented performance improvements. In addition, we show how the framework can be flexibly configured to meet specific delay tolerance constraints according to specific context policies. With regard to connectivity relaying service, we introduce a novel scheme of using D2D communications for enabling data relay services in partial Not-Spots, where a client without local network access may require data relay by other devices. Depending on specific social application scenarios, this piece of work introduces tailored algorithms in order to achieve optimised data relay service performance. The approach is to exploit the network’s knowledge on its local user mobility patterns to identify best helper devices for participating in data relay operations. This framework is also supported with our proposed helper selection optimisation algorithm based on prediction of individual user mobility. According to our simulation analysis, based on both theoretical mobility models and real human mobility data traces, the proposed scheme is able to flexibly support different service requirements in specific social application scenarios.