Mobile network operators are currently faced with a number of challenges at the market. The revenues from voice services have decreased the last couple of years. Mobile broadband access services are being adopted and the demand is increasing. The increasing traffic volumes require investments in order to increase the network capacity. This development leads to a large interest in network solutions that can offer high capacity and low cost. Besides the use of more efficient radio access technology mobile network operators use strategies for network deployment and operation involving other market actors. Operators share networks with competitors or outsource network deployment and operation to other companies, e.g. suppliers of network equipment. In these examples the mobile operators cooperate about the networks, the relations to end-users are the same as if the operator would operate the network on its own. However, in other areas other actors enter the market for mobile services where mobile operators traditionally have been the dominant player. Handset manufacturers and Internet companies offer value added services and applications to the end-users. They also establish relations with customers of the mobile operators. Hence, mobile operators look into new technical solutions and services in order to reduce costs and find new services and sources of revenues. Many of the networking solutions and services require that the operator cooperates with some other actor. In this PhD thesis cooperation strategies of mobile network operators are analyzed including cooperation with competitors, customers and different types of partners. The partner can be a provider of a non-telecom service like public transportation, financial institutes or third parties taking intermediary roles. The main research questions in the thesis revolves around why and how mobile operators cooperate. The drivers for cooperation and the way the cooperation is organized is analyzed for a number of cases. Three types of services and markets are analyzed: - Public mobile broadband access services - Services and solutions for indoor wireless access - Mobile payment, ticketing and contactless services A number of technical solutions, business concepts and different types of cooperation and business scenarios have been investigated. Two overall research questions that are applicable for all cases of cooperation are identified for the analysis. - What are the main drivers for a specific type of cooperation? - In what ways can the actors organize the cooperation? / QC 20110121 / Affordable Wireless Broadband Access / Force

Modelling and Simulation (M&S) is a multi-disciplinary field that is widely used in various domains. It provides a means to study complex systems before actual physical prototyping and helps lowering, amongst others, manufacturing and training costs. However, as M&S gains more popularity, the demand on reducing time and resource costs associated with development and validation of simulation models has also increased. Composing simulation models of reusable and validated simulation components is one approach for addressing the above demand. This approach, which is still an open research issue in M&S, requires a composition process that is able to support a modeller with discovery and identification of components as well as giving feedback on feasibility of a composition. Combining components in order to build new simulations raise the non-trivial issue of composability. Composability has been defined as the capability to select and assemble reusable simulation components in various combinations into simulation systems to meet user requirements. There are three main types of composability, syntactic, semantic and pragmatic. Syntactic composability is concerned with the compatibility of implementation details, such as parameter passing mechanisms, external data accesses, and timing mechanisms. It is the question of whether a set of components can be combined. Semantic composability, on the other hand, is concerned with the validity of the composition, and whether the composed simulation is meaningful. Pragmatic composability is yet another type which is concerned with the context of the simulation, and whether the composed simulation meets the intended purpose of the modeller. Of these three types syntactic composability is easiest to accomplish and some significant progresses on this issue have been reported in the literature. Semantic and pragmatic composability are much harder to achieve and has inspired many researchers to conduct both theoretical and experimental research. The Base Object Model (BOM) is a new concept identified within M&S community as a potential facilitator for providing reusable model components for the rapid construction and modification of simulations. Although BOMs exhibit good capabilities for reuse and composability they lack the required semantic information for semantic matching and composition. There is little support for defining concepts and terms in order to avoid ambiguity, and there is no method for matching behaviour of conceptual models (i.e., state machines of the components), which is required for reasoning about the validity of BOM compositions. In this work we have developed a framework for component-based model development that supports both syntactic and semantic composability of simulation models by extending the BOM concept using ontologies, Semantic Web and Web Services technologies, and developing a rule-based method for reasoning about BOM compositions. The issue of pragmatic composability has not been the focus of this work, and it has only been partly addressed. The framework utilises intelligent agents to perform discovery and composition of components, according to the modeller needs. It includes a collaborative environment, a semantic distributed repository and an execution environment to support model development and execution process. The basic assumption of this work is that semantic composability should be achieved at conceptual level. Through precise definition and specification of components’ semantic and syntax one can capture the basic requirements for matching and semantically meaningful composition of those components. This requires a common methodology for specification of simulation components. The specification methodology consists of meta-models describing simulation components at different levels. In order to enable automatic matching of meta-models they are formalized and structured using Semantic Web technology in OWL (Web Ontology Language). Hence, the models are based on ontologies to avoid misunderstanding and to provide unambiguous definitions as a basis for reasoning about syntactic and semantic validity of compositions. / QC 20100830

The strategic management literature indirectly considers entrepreneurship as a subset of strategy, and the historical evolution of the field, specifically that of the Entrepreneurship division of the Academy of Management. Schendel (1990) which placed great emphasis on the topic of entrepreneurship and admitted that some argue that entrepreneurship is at the very heart of strategic management. This thesis explores the strategic use of entrepreneurship in the telecommunication industry. Through the use of strategic entrepreneurship theories both from the strategy and entrepreneurial fields provide the thesis with a foundation to explore and extract empirical results from two case samples known as Vox telecom and Telkom limited. Through an Interpretivist research design which includes thirty interviews in three different phases resulted in the empirical primary data for analysis. The research approach was carried out through an adaptive GT (Grounded Theory) technique which allowed the thesis to capture industry and organisational specific behaviours. The adaptive GT resulted in open, axial and selective coding which finally represented three themed domains. The domains include: the environmental, innovation and corporate orientation domain. The adaptive GT results were conducted through eighteen steps which finally represented three cycles. Chapter 6 represent the first cycle, which demonstrate the analysis and result of the primary data which was gathered during the 1st interview phase, mostly collecting entrepreneurial management practises while the 2nd interview phase represent the strategic organisational empirical findings. The result mainly describes the telecom industry through the scope of the two organisations in our sample, namely Telkom and Vox telecom in South Africa. The second cycle demonstrates the analysis and results which ultimately described the thesis knowledge contribution. The result is displayed and demonstrated in Chapter7 as the Telepreneur framework. The Telepreneur framework includes three models, namely the Telenetwork, Technovation and Telepreneurship model. Finally, in Chapter8 we attempt to test the formulated Telepreneur framework. This chapter represent the third cycle in which describes the result and analysis of the tested Telepreneur framework. The testing is conducted through evaluating the Telepreneur framework in the telecom industry through the third interview phase. The testing processes use two sets of survey data therefore quantitatively testing the result against specified industry data to further generalize the Telepreneur frame. In the end the outcome demonstrated a positive correlation regards the suggested formulated findings grounded in theory verses the empirical testing of the two sample cases and secondary survey data.

<p>The strategic management literature indirectly considers entrepreneurship as a subset of strategy, and the historical evolution of the field, specifically that of the Entrepreneurship division of the Academy of Management. Schendel (1990) which placed great emphasis on the topic of entrepreneurship and admitted that some argue that entrepreneurship is at the very heart of strategic management. This thesis explores the strategic use of entrepreneurship in the telecommunication industry.</p><p>Through the use of strategic entrepreneurship theories both from the strategy and entrepreneurial fields provide the thesis with a foundation to explore and extract empirical results from two case samples known as Vox telecom and Telkom limited. Through an Interpretivist research design which includes thirty interviews in three different phases resulted in the empirical primary data for analysis. The research approach was carried out through an adaptive GT (Grounded Theory) technique which allowed the thesis to capture industry and organisational specific behaviours. The adaptive GT resulted in open, axial and selective coding which finally represented three themed domains. The domains include: the environmental, innovation and corporate orientation domain.</p><p>The adaptive GT results were conducted through eighteen steps which finally represented three cycles. Chapter 6 represent the first cycle, which demonstrate the analysis and result of the primary data which was gathered during the 1^st interview phase, mostly collecting entrepreneurial management practises while the 2^nd interview phase represent the strategic organisational empirical findings. The result mainly describes the telecom industry through the scope of the two organisations in our sample, namely Telkom and Vox telecom in South Africa.</p><p>The second cycle demonstrates the analysis and results which ultimately described the thesis knowledge contribution. The result is displayed and demonstrated in Chapter7 as the Telepreneur framework. The Telepreneur framework includes three models, namely the Telenetwork, Technovation and Telepreneurship model.</p><p>Finally, in Chapter8 we attempt to test the formulated Telepreneur framework. This chapter represent the third cycle in which describes the result and analysis of the tested Telepreneur framework. The testing is conducted through evaluating the Telepreneur framework in the telecom industry through the third interview phase. The testing processes use two sets of survey data therefore quantitatively testing the result against specified industry data to further generalize the Telepreneur frame. In the end the outcome demonstrated a positive correlation regards the suggested formulated findings grounded in theory verses the empirical testing of the two sample cases and secondary survey data.</p>

<p>The ongoing wireless communication evolution offers improvements for industrial applications where traditional wireline solutions causes prohibitive problems in terms of cost and feasibility. Many of these new wireless applications are packet oriented and time-critical. The deadline dependent coding (DDC) communication protocol presented here is explicitly intended for wireless real-time applications. The objective of the work described in this thesis is therefore to develop the foundation for an efficient and reliable real-time communication protocol for critical deadline dependent communication over unreliable wireless channels.</p><p>Since the communication is packet oriented, block codes are suitable for error control. Reed-Solomon codes are chosen and incorporated in a concatenated coding scheme using iterative detection with trellis based decoding algorithms. Performance bounds are given for parallel and serially concatenated Reed-Solomon codes using BPSK. The convergence behavior of the iterative decoding process for serially concatenated block codes is examined and two different stopping criteria are employed based on the log-likelihood ratio of the information bits.</p><p>The stopping criteria are also used as a retransmission criterion, incorporating the serially concatenated block codes in a type-I hybrid ARQ (HARQ) protocol. Different packet combining techniques specifically adapted to the concatenated HARQ (CHARQ) scheme are used. The extrinsic information used in the iterative decoding process is saved and used when decoding after a retransmission. This technique can be seen as turbo code combining or concatenated code combining and is shown to improve performance. Saving the extrinsic information may also be seen as a doping criterion yielding faster convergence. As such, the extrinsic information can be used in conjunction with traditional diversity combining schemes. The performance in terms of bit error rate and convergence speed is improved with only negligible additional complexity.</p><p>Consequently, CHARQ based on serially concatenated block codes using iterative detection creates a flexible and reliable scheme capable of meeting specified required realtime constraints.</p>

<p>Motivated by current applications in multihop transmission and ad hoc networks, the classical three-node relay channel consisting of a source-destination pair and a relay has received significant attention. One of the crucial aspects of the relay channel is the design of proper relaying protocols, i.e., how the relay should take part into transmission. The thesis addresses this problem and provides a partial answer to that.</p><p>In this thesis, we propose and study two novel relaying protocols. The first one is based on constellation rearrangement (CR) and is suitable for higher-order modulation schemes. With CR, the relay uses a bit-symbol mapping that is different from the one used by the source. We find the optimal bit-symbol mappings for both the source and the relay and the associated optimal detectors, and show that the improvement over conventional relaying with Gray mapping at the source and the relay can amount to a power gain of several dB. This performance improvement comes at no additional power or bandwidth expense, and at virtually no increase in complexity. The second one is a half-duplex decode-and-forward (DF) relaying scheme based on partial repetition (PR) coding at the relay. With PR, if the relay decodes the received message successfully, it re-encodes the message using the same channel code as the one used at the source, but retransmits only a fraction of the codeword. We analyze the proposed scheme and optimize the cooperation level (i.e., the fraction of the message that the relay should transmit). We compare our scheme with conventional repetition in which the relay retransmits the entire decoded message, and with parallel coding, and additionally with dynamic DF. The finite SNR analysis reveals that the proposed partial repetition can provide a gain of several dB over conventional repetition. Surprisingly, the proposed scheme is able to achieve the same performance as that of parallel coding for some relay network configurations, but at a much lower complexity.</p><p>Additionally, the thesis treats the problem of resource allocation for collaborative transmit diversity using DF protocols with different type of CSI feedback at the source. One interesting observation that emerges is that the joint powerbandwidth allocation only provides marginal gain over the relaying protocols with optimal bandwidth allocation. </p>

The ongoing wireless communication evolution offers improvements for industrial applications where traditional wireline solutions causes prohibitive problems in terms of cost and feasibility. Many of these new wireless applications are packet oriented and time-critical. The deadline dependent coding (DDC) communication protocol presented here is explicitly intended for wireless real-time applications. The objective of the work described in this thesis is therefore to develop the foundation for an efficient and reliable real-time communication protocol for critical deadline dependent communication over unreliable wireless channels. Since the communication is packet oriented, block codes are suitable for error control. Reed-Solomon codes are chosen and incorporated in a concatenated coding scheme using iterative detection with trellis based decoding algorithms. Performance bounds are given for parallel and serially concatenated Reed-Solomon codes using BPSK. The convergence behavior of the iterative decoding process for serially concatenated block codes is examined and two different stopping criteria are employed based on the log-likelihood ratio of the information bits. The stopping criteria are also used as a retransmission criterion, incorporating the serially concatenated block codes in a type-I hybrid ARQ (HARQ) protocol. Different packet combining techniques specifically adapted to the concatenated HARQ (CHARQ) scheme are used. The extrinsic information used in the iterative decoding process is saved and used when decoding after a retransmission. This technique can be seen as turbo code combining or concatenated code combining and is shown to improve performance. Saving the extrinsic information may also be seen as a doping criterion yielding faster convergence. As such, the extrinsic information can be used in conjunction with traditional diversity combining schemes. The performance in terms of bit error rate and convergence speed is improved with only negligible additional complexity. Consequently, CHARQ based on serially concatenated block codes using iterative detection creates a flexible and reliable scheme capable of meeting specified required realtime constraints.