This thesis consists of two parts addressing two different problems in fading channels. The first part deals with asynchronous cooperative relay communication. The assumption of nodes in a cooperative communication relay network operating in synchronous fashion is often unrealistic. In this work we consider two different models of asynchronous operation in cooperative-diversity networks experiencing slow fading and examine the corresponding Diversity-Multiplexing Tradeoffs (DMT). For both models, we propose protocols and distributed space-time codes that asymptotically achieve the transmit diversity bound on DMT for all multiplexing gains and for number of relays N ≥ 2. The distributed space-time codes for all the protocols considered are based on Cyclic Division Algebras (CDA). The second part of the work addresses the DMT analysis of diversity embedded codes for MIMO channels. Diversity embedded codes are high rate codes that are designed so that they have a high diversity code embedded within them. This allows a form of opportunistic communication depending on the channel conditions. The high diversity code ensures that at least a part of the information is received reliably, whereas the embedded high rate code allows additional information to be transferred if the channel is good. This can be thought of coding the data into two streams: high priority and low priority streams so that the high priority stream gets a better reliability than the lower priority stream. We show that superposition based diversity embedded codes in conjunction with naive single stream decoding is sub-optimal in terms of the DM tradeoff. We then construct explicit diversity embedded codes by the superposition of approximately universal space-time codes from CDAs. The relationship between broadcast channels and the diversity embedded setting is then utilized to provide some achievable Diversity Gain Region (DGR) for MIMO broadcast Channels.

La coopération des transmetteurs dans les système multi-antennes a été reconnue comme un outil prometteur pour éviter ou aligner les interférence résultant d'une réutilisation agressive de la bande spectrale. Il est usuellement supposé que les estimées de canal sont parfaitement partagées entre tous les transmetteurs entrant en coopération, ce qui n'est pas adaptée à de nombreuses situations où des émetteurs éloignés visent à coopérer. C'est pourquoi nous étudions le cas de réseaux sans-fil où des transmetteurs émettent d'une manière coopérative bien qu'ils ne puissent échanger que d'une manière imparfaite l'information de canal obtenue localement. Ce partage imparfait de l'information de canal donne lieu à une configuration d'information de canal, dénotée comme " distribuée ", où chaque transmetteur reçoit une estimée du canal multi-utilisateurs qui lui est propre, à partir de laquelle il détermine ses paramètres de transmission. Nous étudions tout d'abord les conséquences de la configuration à information de canal distribuée sur le précodage. En particulier, nous mettons en évidence l'inefficacité des méthodes conventionnelles de précodage lorsque confrontées à une configuration à information de canal distribuée. Nous passons ensuite à un autre aspect de ce scenario, qui est la détermination de " qui doit savoir quoi ", lorsqu'il s'agit de l'information de canal disponible aux transmetteurs engagés dans la coopération. À l'opposé de la méthode gourmande en ressource qui consiste à allouer à chaque transmetteur la même information de canal, il est montrée comment une allocation non-uniforme de l'information de canal aux transmetteurs peut donner lieu à des gain importants, en fonction de la géométrie du réseau considéré.

Reliable and energy-efficient delivery of multimedia to mobile terminals in dynamic networks is a very challenging problem. In this thesis, we focus on a cooperative extension to the Digital Video Broadcasting – Handheld (DVB-H) standard, forming a cooperative broadcast network whereby terminal-to-terminal cooperation creates a distributed form of multi-input-multi-output (MIMO) that supplements existing fixed network infrastructure. First, we develop a novel and computationally-efficient hierarchical Markov model that is able to accurately perform a cross-layer packet error mapping between the physical and transport layers of the DVB-H/IPDC (IP DataCast) protocol stack. We then construct a discrete-event simulator in MATLAB® that incorporates all of the necessary modules to conduct dynamic multiterminal network simulations. Next, the convergence of cooperative wireless communication, Raptor application layer forward error correction (AL-FEC) and Network Coding (NC) is examined. Originally proposed for broadcasting over the Internet, the application of Raptor codes to wireless cooperative communications networks has been limited to date, but they have been mandated for use in DVB-H. Network coding is used to reduce energy consumption by opportunistically recombining and rebroadcasting required combinations of packets. Two novel coding-enabled cooperative relaying protocols are developed for multicast and multiple unicast file distribution scenarios that are transparent, fully distributed, and backwards compatible with today's systems. Our protocols are able to exploit several different forms of diversity inherent to modern wireless networks, including spatial diversity, radio interface diversity, and symbol diversity. Extensive simulations show that our protocols simultaneously achieve breakthroughs in network energy efficiency and reliability for different terminal classes and densities, allowing greatly improved user experiences. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2010-08-03 19:45:54.943

Road accidents represent a serious social problem and are one of the leading causes of human death and disability on a global scale. To reduce the risk and severity of a road accident, a variety of new safety applications can be realized through wireless communications among vehicles driving nearby each other, or among vehicles and especially deployed road side units (RSUs), a technology known as a vehicular ad hoc network (VANET). Most of the VANET-enabled safety applications are based on broadcasting of safety messages by vehicles or RSUs, either periodically or in case of an unexpected event, such as a hard brake or dangerous road condition detection. Each broadcast safety message should be successfully delivered to the surrounding vehicles and RSUs without any excess delay, which is one of the main functions of a medium access control (MAC) protocol proposed for VANETs. This thesis presents VeMAC, a new multichannel time division multiple access (TDMA) protocol specifically designed to support the high priority safety applications in a VANET scenario. The ability of the VeMAC protocol to deliver periodic and event-driven safety messages in VANETs is demonstrated by a detailed delivery delay analysis, including queueing and service delays, for both types of safety messages. As well, computer simulations are conducted by using MATLAB, the network simulator ns-2, and the microscopic vehicle traffic simulator VISSIM, in order to evaluate the performance of the VeMAC protocol, in comparison with the IEEE 802.11p standard and the ADHOC MAC protocol (another TDMA protocol proposed for ad hoc networks). A real city scenario is simulated and different performance metrics are evaluated, including the network goodput, protocol overhead, channel utilization, protocol fairness, probability of a transmission collision, and safety message delivery delay. It is shown that the VeMAC protocol considerably outperforms the existing MAC schemes, which have significant limitations in supporting VANET safety applications. In addition to enhancing road safety, in-vehicle Internet access is one of the main applications of VANETs, which aims at providing the vehicle passengers with a low-cost access to the Internet via on-road gateways. This thesis presents a new strategy for deploying Internet gateways on the roads, in order to minimize the total cost of gateway deployment, while ensuring that a vehicle can connect to an Internet gateway (using multihop communications) with a probability greater than a specified threshold. This cost minimization problem is formulated by using binary integer programming, and applied for optimal gateway placement in a real city scenario. To the best of our knowledge, no previous strategy for gateway deployment has considered the probability of multihop connectivity among the vehicles and the deployed gateways. In order to allow a vehicle to discover the existence of an Internet gateway and to communicate with the gateway via multihops, a novel data packet routing scheme is proposed based on the VeMAC protocol. The performance of this cross-layer design is evaluated for a multichannel VANET in a highway scenario, mainly in terms of the end-to-end packet delivery delay. The packet queueing at each relay vehicle is considered in the end-to-end delay analysis, and numerical results are presented to study the effect of various parameters, such as the vehicle density and the packet arrival rate, on the performance metrics. The proposed VeMAC protocol is a promising candidate for MAC in VANETs, which can realize many advanced safety applications to enhance the public safety standards and improve the safety level of drivers/passengers and pedestrians on roads. On the other hand, the proposed gateway placement strategy and packet routing scheme represent a strong step toward providing reliable and ubiquitous in-vehicle Internet connectivity.

主管機關於發照機制之選擇及其執照核發決定，不僅是滲透到無線廣電產業管制架構的每一處縫隙，也反映出社會價值之優先序位。 從上個世紀以來，解除管制、數位科技與匯流現象高度衝擊了過去以執照為核心的無線廣電管制體系，也引發了一波管制革新之需求。形式上，無線廣電服務與電台執照是一系列權利義務與一套法律程序之化身，但從其功能面來看，執照之核發寓含至少有「註冊登記，分類管理」、「資源分配」、「限制市場參進與競爭」、「費用徵納」及「行為監管」等多元之目標功能。在英美，無線廣電執照之核發反映出該國無線廣電體系之社會角色定位，也反應出不同廣電體系下執照釋出及其頻率核配方式與結果之影響；管制革新也同樣令其重新認知了傳統執照制度中課予廣電業者公益義務之價格問題。 拍賣法在廣電頻譜及經營特許之應用上，除有先例可循外，亦被認為將可以矯正過去傳統以命令與控制模式支配下之執照核發制度之缺失，並將因此增加頻譜使用效率、提升全體福祉。本文因此透過英美等國之制度規範與經驗之分析，來檢驗此一說法。期待藉由瞭解拍賣法及其相關特殊背景下運作之優劣得失，及晚近崛起之相關替選方案，能提供未來政策制訂者在商業廣電執照管理之改革議題上有更豐富的視野。 儘管拍賣法在無線通訊領域應用上，現階段看來有相當誘人的成果，但本文認為，無線廣電事業有其特殊性，傳統頻率指配結合營業特許之執照體系，在使用拍賣法上，將可能產生近用、市場競爭、使用效率、內容多元等目標上無一討好之結果。再者，要達成自由市場或市場模式追求之效率目標，也並非單純使用拍賣法即可；相關配套措施之施行，同樣不可或缺。再者，我國無線廣電體制與英美更有不同，因此如何避免出現主管機關缺乏落實政策目標之能力，至關重要。 目前我國無線商業廣電執照核發制度之問題，可說在頻譜與內容管制雙重目標間迷失；問題焦點並不在於拍賣或審議制的二選一習題上，而應是致力於明確化分配標準、公開透明的競爭程序。此外，在引入市場機制於執照制度、期能促進效率與效能之同時，如何平衡執照管理中的私益與公益問題，仍是數位匯流時代無線廣電執照管理議題之核心。 / The authority's choice of a licensing mechanism and decisions thereof not only permeate nearly the entire regulatory fabric of our broadcast industries, but reflect our society's priorities. Licensing, nominally, is a mutual promise by the legal procedure; moreover, it is also about the registration, limited competition, distribution of resourses, charges, and the code of conduct. Since last century, broadcast laws and regulations have been bombarded with deregulation, digitization, and convergence, and that is conglomerated to push the reform of broadcast licensing. Simultaneously, the communications revolution, like U.K. or U.S., has thrown into question the value of imposing public interest obligations on radio and television broadcasters. Broadcast licensing seems to be so daunting that some people anoint a few constituencies with very pressing appeals, give them special leverage, and throw everything else back on the market. The auction apologists would argue that the government should set clear and definite standards and tough performance requirements to ensure that good systems and service will result, whoever is the highest bidder. In a pure auction era, where dollars are equated with public worth and maximizing dollars will be the most important criterion, there will be strong pressure to also base allocation and allotment decisions on this standard. The merit of auctions in wireless communications licensing may be conspicuous, but the broadcast industry is unique and more complicated so that the change of a licensing mechanism, from the marketplace approach, could be made that a revised public interest standard and obligations failed to address the fundamental challenge--to reassess the power of the regulator when implementing the public interest obligations. Auctions of radio spectrum or broadcasting concession, in other words, will generate their own serious problems that should not be underestimated or denied. On broadcast licensing of Taiwan, auctions will not be the life buoy to predicaments of broadcast industries; on the contrary, a top priority is to enhance the clearness and definition, transparency, and fair competition, whether the authority prefers imitating an auction to innovating the traditional selection procedure, beauty contest, through a more competitive approach or not. Besides, we shall inspecting the key point of whether or not competition and the public interest are compatible in the ongoing dialectic still, continuing to struggle toward a balance between private initiative and public oversight.

Ο όγκος των δεδομένων που απαιτούνται για τον έλεγχο της ορθής λειτουργίας ενός συστήματος που υλοποιείται σε ένα ολοκληρωμένο κύκλωμα είναι πάρα πολύ μεγάλος. Αυτό συνεπάγεται ότι ο χρόνος που απαιτείται για τον έλεγχο της ορθής λειτουργίας του ολοκληρωμένου κυκλώματος μπορεί να είναι απαγορευτικά μεγάλος. Για τη μείωση του απαιτούμενου χρόνου χρησιμοποιούνται διάφορες τεχνικές συμπίεσης των δεδομένων δοκιμής. Κάποιες από αυτές τις τεχνικές βασίζονται στην αποστολή κοινών δεδομένων δοκιμής ταυτόχρονα σε περισσότερες από μία μονάδες του ολοκληρωμένου κυκλώματος. Στην εργασία αυτή υλοποιούμε μια από αυτές τις τεχνικές που βασίζεται στην ύπαρξη μονοπατιών ολίσθησης (scan paths) στις μονάδες του ολοκληρωμένου κυκλώματος. Για την περαιτέρω μείωση του χρόνου που απαιτείται για τον έλεγχο της ορθής λειτουργίας του ολοκληρωμένου κυκλώματος γίνεται χρονοπρογραμματισμός της σειράς με την οποία θα ελεγχθεί η ορθή λειτουργία των διαφόρων μονάδων του ολοκληρωμένου κυκλώματος. / The volume of data that is required to test a SoC is too much big. This means that the time that is required for testing can be prohibitorily big. For the reduction of required time are used various techniques of data compaction.Some of these techniques are based on broadcasting the same value to all of the cores on a SoC.In this work we use one of these techniques that are based on the existence of scan chains in the core (broadcast scan).For further reduction of time that is required for testing a circuit we use a core testing schedule algorithm.

Thesis (MA)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The controversy around the broadcasting of court proceedings has reigned in the United States since the 1950s, reaching a peak with the trial of O.J. Simpson, widely interpreted as an example of the destructive effect of a "media circus" on the administration of justice. In many other U.S. courtrooms, however, television and radio journalists do their work unobtrusively, professionally and to the benefit of their viewers and listeners. The King Commission of Inquiry into allegations of match-fixing in cricket gave South Africa its first experience of television and radio coverage of judicial proceedings, and lay the basis for a more liberal approach to electronic coverage of courts. The Constitution protects freedom of expression, including the freedom to receive and impart information. This has been interpreted by the High Court as conferring on radio journalists the freedom to record and broadcast the King Commission's proceedings. It is argued in this study that the High Court's reasoning could be applied with equal force to television, and to coverage of the courts. It is suggested a trial period of electronic coverage of courts, under clear guidelines for journalists and legal practitioners, may provide greater clarity on the desirability of allowing electronic coverage of courts on a permanent basis. / AFRIKAANSE OPSOMMING: Die netelige vraagstuk rondom die uitsaai van hofverrigtinge het alreeds in the vyftigerjare van die vorige eeu in die Verenigde State ontstaan. Die vervolging van O.J. Simpson was 'n hoogtepunt in die debat. Dié saak word gereeld voorgehou as 'n voorbeeld van die nadelige effek wat 'n "mediasirkus" op die regsproses kan uitoefen. Maar in baie ander Amerikaanse howe doen radio- en televisiejoernaliste hulle werk sonder steurnis, professioneel, en ten voordeel van hul luisteraars and kykers. The Kingkommissie van Ondersoek na beweringe van oneerlikheid in krieket was Suid-Afrika se eerste ervaring van elektroniese dekking van 'n regterlike proses, and kan moontlik die basis vorm vir 'n meer liberale benadering tot elektroniese dekking van howe. Die Grondwet waarborg vryheid van uitdrukking, insluitende die vryheid om inligting uit te stuur en te ontvang. Die Hooggeregshof het onlangs beslis hierdie vryheid beteken radiojoernaliste mag die verrigtinge van die Kingkommissie opneem en uitsaai. In hierdie studie word geargumenteer dat die Hooggeregshof se beslissing ook van toepassing kan wees op televisie, en op hofverrigtinge. Daar word voor die hand gedoen dat Suid- Afrikaanse howe vir 'n proeftydperk elekroniese dekking van hofverrigtinge toelaat, met streng reëls vir joernaliste en regspraktisyns. So 'n proefneming kan dalk groter duidelikheid verskaf oor die voor- en nadele van televisie- en radiodekking van howe op 'n permanente basis.

ÚSTAV HOSPODÁŘSKÝCH A SOCIÁLNÍCH DĚJIN ANOTACE DIZERTAČNÍ PRÁCE V zajetí televize Aktéři, televizní žánry a programy v USA a Československu v 2. polovině 20. století CAPTURED BY TELEVISION ACTORS, TELEVISION GENRES AND PROGRAM IN THE US AND CZECHOSLOVAKIA IN THE SECOND HALF OF THE 20TH CENTURY Mgr. Michaela Blažková Vedoucí dizertační práce: Doc. PhDr. Michal Pullmann, Ph.D. Praha 2018 Summary Against the backdrop of political, economic and cultural changes, changes have been taking place in the United States of America in the 1950s, even at the level of whole society. One of the crucial changes was the entrance of television broadcasting into the environment of social relations and relationships. Television, as a new form of media that aims to entertain, inform and educate, had very quickly found its way to the most of households where it has settled adamantly. Initially, however, a programmed composition was not firmly established, which sought its stable image at this time in the form of trial and error. In the Czechoslovakia, and later also in the Czech Republic, TV has also won many supporters. The technical form of the broadcasting scheme was formed on the basis of the actual technical possibilities and the range of the transmitting time. In addition to political influence on broadcasting until 1989,...

This case study researches newsroom convergence as a process at the Mail & Guardian newspaper and their online edition the Mail & Guardian Online. It focuses on the reporters’ and editors’ attitudes towards newsroom convergence and on cultural resistance against change; one of the major challenges in the process. With structured interviews, observations and questionnaires it was analysed that communication problems between the newsrooms, different production cycles and time management issues are other prominent difficulties. The case study furthermore provides a snapshot of the convergence phenomenon as a process in a particular South African news organisation. The outcomes could not only assist other news companies with convergence plans but also be used as a pilot study for further research on converged newsrooms in South Africa.

Traditionally, connection management applications (referred to as patchbays) for high-speed audio networking, are predominantly developed using third-generation languages such as C, C# and C++. Due to the rapid increase in distributed audio/video network usage in the world today, connection management applications that control signal routing over these networks have also evolved in complexity to accommodate more functionality. As the result, high-speed audio networking application developers require a tool that will enable them to develop complex connection management applications easily and within the shortest possible time. In addition, this tool should provide them with the reliability and flexibility required to develop applications controlling signal routing in networks carrying real-time data. High-speed audio networks are used for various purposes that include audio/video production and broadcasting. This investigation evaluates the possibility of using Adobe Flash Professional 8, using ActionScript 2.0, for developing connection management applications. Three patchbays, namely the Broadcast patchbay, the Project studio patchbay, and the Hospitality/Convention Centre patchbay were developed and tested for connection management in three sound installation networks, namely the Broadcast network, the Project studio network, and the Hospitality/Convention Centre network. Findings indicate that complex connection management applications can effectively be implemented using the Adobe Flash IDE and ActionScript 2.0.