Next generation high performance systems are being standardised assuming a generic service delivery paradigm capable of supporting a diversity of circuit and importantly packet services. However, this flexibility comes at a cost which is the increased complexity of the dimensioning, planning, optimisation and QoS provisioning with respect to previous generation single-service mobile systems. Accurate system dimensioning is of fundamental importance and this thesis explores this requirement at two levels. Firstly, it departs from the common assumption of static users and examines what is the impact of mobile users on the system capacity. Secondly, it examines the impact of voice and web browsing services on the system dimensioning. In spite of the accuracy of dimensioning and planning, load imbalances occur for different reasons, which result in small-scale congestion events in the system. A load equalisation scheme is proposed which utilises the overlapping areas between neighbouring cells in order to eliminate the load imbalances. Essentially, coverage overlapping is needed in order to achieve ubiquitous coverage, hence to eliminate coverage holes. However, excessive overlapping results in capacity loss in interference-limited systems which is virtually the case with all modern systems. Radio coverage optimisation is needed but today this is performed on a cell-by- cell basis producing sub-optimal results. This thesis proposes an advanced coverage optimisation algorithm which takes into consideration simultaneously all cells within the considered area. For the operators (and also the proposed coverage optimisation algorithm) it is Imperative to have accurate path loss predictions. However, contemporary planning tools come with certain limitations, and often time-consuming and expensive measurement campaigns are organised. This thesis builds on the assumption that mobile systems will be able to locate the position of mobile terminals and subsequently proposes an automated process for the estimation of the radio coverage of the network. Lastly, the assumption regarding the positioning capabilities of the mobile systems Is further exploited in order to enhance the QoS guarantees to mobile users. Thus, various algorithms are examined which perform handovers towards base stations which maximise the survivability of the handed over calls.

Several studies have characterized the path loss properties in industrial environments. However most of them have focused on one frequency, and some two or maximum three frequencies, usually cellular telephone frequencies or the unlicensed ISM bands that are commonly used in various industries. Few, if any, have characterized a larger part of the useable frequency range.This thesis is taking that challenge and investigates the path loss characteristics over a large frequency range, 300 MHz – 3 GHz, in industrial environments. First a measurement system suitable for the harsh environments found in industries is designed and verified. The measurement system is designed as two asynchronous stand-alone units that can be positioned at an arbitrary position to measure the path loss characteristics in any environment without interfering with the normal activities at the location. After that a measurement campaign involving three different types of environments is carried out. The environment types are: first, one highly absorbing – a paper warehouse at a paper mill; second, one highly reflective – a furnace building filled with metal objects and constructions and third, a mine tunnel – located 1 km below the surface of earth which is neither highly reflective nor absorbing but exhibits somewhat wave-guide like characteristics. The environments are shown to have very different behavior when it comes to propagation characteristics. Observations in the first environment reveal an environment that almost cancels out certain frequency bands and only line-of-sight communication is possible, hence no improvement will be achieved if installing systems that take multipath propagation into account, like MIMO. In the second environment reflections are legion; there are so many reflecting surfaces at different angles so any polarization of the signal is almost completely eliminated. Large fading variations were observed.The third environment is the underground mine where signals propagate inside the tunnels like in waveguides. It is shown that there are regions in the spectrum where the path loss dips and that these dips at least partly can be modeled with a simple two-beam propagation model normally used for outdoor propagation over infinite fields. The overall conclusion is that industrial environments are more heterogeneous regarding propagation characteristics than commonly assumed when selecting communication solutions. And that the only way to really know if a radio system will work at a certain location is to measure and characterize the environment.

The most important fact in the mobile industry at the moment is that demand for wireless services will continue to expand in the coming years. Therefore, it is vital to find more spectrums through cognitive radios for the growing numbers of services and users. However, the spectrum reallocations, enhanced receivers, shared use, or secondary markets-will not likely, by themselves or in combination, meet the real exponential increases in demand for wireless resources. Network operators will also need to re-examine network architecture, and consider integrating the fibre and wireless networks to address this issue. This thesis involves driving fibre deeper into cognitive networks, deploying microcells connected through fibre infrastructure to the backbone LTE networks, and developing the algorithms for diverting calls between the wireless and fibre systems, introducing new coexistence models, and mobility management. This research addresses the network deployment scenarios to a microcell-aided cognitive network, specifically slicing the spectrum spatially and providing reliable coverage at either tier. The goal of this research is to propose new method of decentralized-to-distributed management techniques that overcomes the spectrum unavailability barrier overhead in ongoing and future deployments of multi-tiered cognitive network architectures. Such adjustments will propose new opportunities in cognitive radio-to-fibre systematic investment strategies. Specific contributions include: 1) Identifying the radio access technologies and radio over fibre solution for cognitive network infrastructure to increase the uplink capacity analysis in two-tier networks. 2) Coexistence of macro and microcells are studied to propose a roadmap for optimising the deployment of cognitive microcells inside LTE macrocells in the case of considering radio over fibre access systems. 3) New method for roaming mobiles moving between microcells and macrocell coverage areas is proposed for managing spectrum handover, operator database, authentication and accounting by introducing the channel assigning agent entity. The ultimate goal is to reduce unnecessary channel adaptations.

This thesis describes a brief history of radio and electromagnetic waves from a physical point of view. It focuses mainly on radio waves in the VHF and subsequent construction of a radio network in this band. It uses the knowledge of the writer of this wavelength. This thesis is intended as a guide for fellow author.

<p>There exist several known methods for calculation of radio coverage for ground-based systems. As far as we know there are no equivalent methods for the case of flying platforms when the altitudes and speeds are significantly different to those of ground-based systems. </p><p>This thesis describes the theoretical concepts behind calculations of radio coverage for flying platforms. An investigation is made to sort out what is important and possible to employ in a model for simulations. A method is described and implemented in a program for evaluation of flying radio systems. Two typical cases of flight missions are simulated and discussed. </p><p>It is found that the free space model is valid most of the mission time. The contribution from the antennas is found to be small in comparison to the path loss. Further investigations suggested are e.g. better ground reflection models and a better model for the flight mechanics.</p>

There exist several known methods for calculation of radio coverage for ground-based systems. As far as we know there are no equivalent methods for the case of flying platforms when the altitudes and speeds are significantly different to those of ground-based systems. This thesis describes the theoretical concepts behind calculations of radio coverage for flying platforms. An investigation is made to sort out what is important and possible to employ in a model for simulations. A method is described and implemented in a program for evaluation of flying radio systems. Two typical cases of flight missions are simulated and discussed. It is found that the free space model is valid most of the mission time. The contribution from the antennas is found to be small in comparison to the path loss. Further investigations suggested are e.g. better ground reflection models and a better model for the flight mechanics.

When a large number of base stations fail due to the breakdown of some transmission circuit in a mobile cellular network, base stations located in neighboring areas may take over those malfunctioned base stations and continue to provide the access service of mobile communications for users in surrounding areas, thereby reducing the area in which mobile communications are out of service. Therefore, if leased circuits in base stations could complete the route distribution configuration prior to the onset of malfunction, it could decrease the impact of circuit breakdown and traffic loss. Also, the efficiency would be improved if the circuit assignment personnel could complete the job when the leased lines are less, while avoiding reassignment in the future and enhancing the mobile communications operations. In this study, we use a graph structure to represent the present mobile cellular network and establish the route-selection strategies. We define the "Optimal Route Assignment" for a newly constructed base station, which refers to the route assignment that causes least impact on disconnection area when any circuit in the network is broken. We also propose to use A* algorithm for optimal route assignment. However, the computation for the optimal route is time consuming. Measures such as computation time and least hops are considered in designing other strategies for route assignment. These strategies are parametric and we carried out experiments by adjusting and controlling parameters using real routing data. The experimental results demonstrate that there is no single winner among the proposed strategies. We identify a number of best strategies for different operating regions.