Performance Analysis and Enhancement of QoS Framework for Fixed WiMAX Networks. Design, analysis and evaluation of 802.16 Point-to-Multipoint (PMP) Quality of Service Framework based on uplink scheduler and call admission control analysis.

Given the current developments and advances in the scientific and technological aspects of human knowledge and introducing new approaches in various fields of telecommunication technologies and industries, there has been an increasing growth in its players¿ plans and a positive change in their outlooks in order to achieve the target of "anywhere and anytime access". Recent developments of WiMAX (Worldwide interoperability for Microwave Access) networks, as a sign of increasing needs and demands for new telecommunication services and capabilities, have led to revolutions in global telecommunication which should be perceived properly in terms of the commercial and technical aspects in order to enjoy the new opportunities. Most experts believe that WiMAX technology is a preliminary step to develop Fourth Generation networks known as 4G technologies. It has not only succeeded in the utilization of several of the latest telecommunication techniques in the form of unique practical standards, but also paved the way for the quantitative and qualitative developments of high-speed broadband access. IEEE 802.16 Standard introduces several advantages, and one of them is the support for Quality of Services (QoS) at the Media Access Control (MAC) level. For these purposes, the standard defines several scheduling classes at MAC layer to treat service flow in a different way, depending on QoS requirements. In this thesis, we have proposed a new QoS framework for Point-to-Multi Point (PMP) 802.16 systems operating in Time Division Duplexing (TDD) mode over a WirelessMAN-OFDM physical layer. The proposed framework consists of a Call Admission Control (CAC) module and a scheduling scheme for the uplink traffic as well as a simple frame allocation scheme. The proposed CAC module interacts with the uplink scheduler status and it makes its decision based on the scheduler queue status; on the other hand, the proposed scheduling scheme for the uplink traffic aims to support realtime flows and adapts the frame-by-frame allocations to the current needs of the connections, with respect to the grants boundaries fixed by the CAC module. Extensive OPNET simulation demonstrates the effectiveness of the proposed architecture

Opportunistic scheduling algorithms in downlink centralized wireless networks.

Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2005.As wireless spectrum efficiency is becoming increasingly important with the growing demands for wideband wireless service scheduling algorithm plays an important role in the design of advanced wireless networks. Opportunistic scheduling algorithms for wireless communication networks under different QoS constraints have gained popularity in recent years since they have potentials of achieving higher system performance. In this dissertation firstly we formulate the framework of opportunistic scheduling algorithms. Then we propose three new opportunistic scheduling schemes under different QoS criteria and situations (single channel or multiple channel). 1. Temporal fairness opportunistic scheduling algorithm in the short term. We replicate the temporal fairness opportunistic scheduling algorithm in the long term. From simulation results we find that this algorithm improves the system performance and complies with the temporal fairness constraint in the long term. However, the disadvantage of this algorithm is that it is unfair from the beginning of simulation to 10000 time slot on system resource (time slots) allocation - we say it is unfair in the short term. With such a scheme, it is possible that some users with bad channel conditions would starve for a long time (more than a few seconds) , which is undesirable to certain users (say, real-time users). So we propose the new scheme called temporal fairness opportunistic scheduling algorithm in the short term to satisfy users ' requirements of system resource in both short term and long term. Our simulation results show that the new scheme performs well with respect to both temporal fairness constraint and system performance improvement. 2. Delay-concerned opportunistic scheduling algorithm. While most work has been done on opportunistic scheduling algorithm under fairness constraints on user level, we consider users' packet delay in opportunistic scheduling. Firstly we examine the packet delay performance under the long term temporal fairness opportunistic scheduling (TFOL) algorithm. We also simulate the earliest deadline-first (EDF) scheduling algorithm in the wireless environment. We find that the disadvantage of opportunistic scheduling algorithm is that it is unfair in packet delay distribution because it results in a bias for users with good channel conditions in packet delay to improve system performance. Under EDF algorithm, packet delay of users with different channel conditions is almost the same but the problem is that it is worse than the opportunistic scheduling algorithm. So we propose another new scheme which considers both users' channel conditions and packet delay. Simulation results show that the new scheme works well with respect to both system performance improvement and the balance of packet delay distribution. 3. Utilitarian fairness scheduling algorithm in multiple wireless channel networks. Existing studies have so far focused on the design of scheduling algorithm in the single wireless communication network under the fairness constraint. A common assumption of existing designs is that only a single user can access the channel at a given time slot. However, spread spectrum techniques are increasingly being deployed to allow multiple data users to transmit simultaneously on a relatively small number of separate high-rate channels. Not much work has been done on the scheduling algorithm in the multiple wireless channel networks. Furthermore in wire-line network, when a certain amount of resource is assigned to a user, it guarantees that the user gets some amount of performance, but in wireless network this point is different because channel conditions are different among users. Hence, in wireless channel the user's performance does not directly depend on its allocation of system resource. Finally the opportunistic scheduling mechanism for wireless communication networks is gaining popularity because it utilizes the "multi-user diversity" to maximize the system performance. So, considering these three points in the fourth section, we propose utilitarian fairness scheduling algorithm in multiple wireless channel networks. Utilitarian fairness is to guarantee that every user can get its performance requirement which is pre-defined. The proposed criterion fits in with wireless networks. We also use the opportunistic scheduling mechanism to maximize system performance under the utilitarian fairness constraint. Simulation results show that the new scheme works well in both utilitarian fairness and utilitarian efficiency of system resource in the multiple wireless channel situation

An analysis of regulatory frameworks for wireless communications, societal concerns and risk: the case of radio frequency (RF) allocation and licensing.

This thesis analyses how and why culture and geography influence the allocation and licensing of the radio frequency (RF) spectrum in different nations. Based on a broad study of 235 countries, an inter-disciplinary approach is used to explore regulatory frameworks and attitudes toward risk. In addition, detailed case studies of the UK, France, the US and Ecuador provide deeper insights into the main contrasting regulatory styles. Three alternative sociological theories are used to analyse and explain the results for both the in-depth and broad brush studies. The Cultural Theory of Mary Douglas and co-workers is first used to categorise countries in terms of perceptual filters. The empirical findings indicate some countries to be apparently exceptional in their behaviour. The theory of Bounded Rationality is used to investigate and explain these apparent irrationalities. Finally, Rational Field Theory shows how beliefs and values guide administrations in their RF regulation. A number of key factors are found to dominate and patterns emerge. The European RF harmonisation is unique. Following European unification, wireless regulation is divided into two major camps (the EU and the US), which differ in their risk concerns, approach to top-down mandated standards, allocation of RF spectrum to licence-exempt bands and type approval process. The adoption of cellular and TV standards around the world reflects geopolitical and colonial influence. The language of a country is a significant indicator of its analogue TV standard. Interestingly, the longitude of a country to a fair extent defines RF allocation: Africa and West Asia follow Europe, whereas the Americas approximate the US. RF regulation and risk tolerability differ between tropical and non-tropical climates. The collectivised/centralised versus the individualised/market-based rationalities result in different regulatory frameworks and contrasting societal and risk concerns. The success of the top-down European GSM and the bottom-up Wi-Fi standards reveal how the central- planning and market-based approaches have thrived. Attitudes to RF human hazards and spurious emissions levels reveal that the US, Canada and Japan are more tolerant of these risks than Europe. Australia, Canada, New Zealand, UK and USA encourage technological innovation. A practical benefit of this study is that it will give regulators more freedom to choose a rational RF licensing protocol, by better understanding the possibly self-imposed boundaries of cultural and geographical factors which are currently shaping allocation. Academically, there is utility in undertaking a cultural and geographic analysis of a topic that is mostly the domain of engineering, economic and legal analysts

Network reputation-based quality optimization of video delivery in heterogeneous wireless environments

The mass-market adoption of high-end mobile devices and increasing amount of video traffic has led the mobile operators to adopt various solutions to help them cope with the explosion of mobile broadband data traffic, while ensuring high Quality of Service (QoS) levels to their services. Deploying small-cell base stations within the existing macro-cellular networks and offloading traffic from the large macro-cells to the small cells is seen as a promising solution to increase capacity and improve network performance at low cost. Parallel use of diverse technologies is also employed. The result is a heterogeneous network environment (HetNets), part of the next generation network deployments. In this context, this thesis makes a step forward towards the “Always Best Experience” paradigm, which considers mobile users seamlessly roaming in the HetNets environment. Supporting ubiquitous connectivity and enabling very good quality of rich mobile services anywhere and anytime is highly challenging, mostly due to the heterogeneity of the selection criteria, such as: application requirements (e.g., voice, video, data, etc.); different device types and with various capabilities (e.g., smartphones, netbooks, laptops, etc.); multiple overlapping networks using diverse technologies (e.g., Wireless Local Area Networks (IEEE 802.11), Cellular Networks Long Term Evolution (LTE), etc.) and different user preferences. In fact, the mobile users are facing a complex decision when they need to dynamically select the best value network to connect to in order to get the “Always Best Experience”. This thesis presents three major contributions to solve the problem described above: 1) The Location-based Network Prediction mechanism in heterogeneous wireless networks (LNP) provides a shortlist of best available networks to the mobile user based on his location, history record and routing plan; 2) Reputation-oriented Access Network Selection mechanism (RANS) selects the best reputation network from the available networks for the mobile user based on the best trade-off between QoS, energy consumptions and monetary cost. The network reputation is defined based on previous user-network interaction, and consequent user experience with the network. 3) Network Reputation-based Quality Optimization of Video Delivery in heterogeneous networks (NRQOVD) makes use of a reputation mechanism to enhance the video content quality via multipath delivery or delivery adaptation

Serviços OTT TV: aspectos técnico-económicos

Mestrado em Engenharia Eletrónica e TelecomunicaçõesThe breadth of availability and variety of online video contents has helped to encourage a far more mobile experience, which has proved particularly popular among younger generations. Over The Top (OTT) services, particularly those on-demand video platforms, became more and more attractive to consumers when compared with the current main TV packages. This document describes how the video OTT Ecosystem works from a technical side. The description presented reaches both ends of the distribution chain: from how the video signals are acquired and processed, thru all the way to how they are delivered to the client, passing by the challenges and consequences that such services have on the network. The main objective of this dissertation is to understand the possibility to create in Portugal a new operator where the core business is video delivery using only OTT services.A amplitude e variedade de conteúdos disponíveis online têm ajudado a promover uma experiência cada ver mais móvel da televisão, serviço que se tem revelado particularmente popular entre os mais jovens. Serviços Over The Top (OTT), sobretudo aqueles disponíveis através de plataformas de video on-demand, têm-se tornado cada vez mais atraentes para os consumidores, em comparação com os atuais pacotes de televisão. Este documento descreve como funciona, do ponto de vista técnico, o ecossistema do vídeo sobre OTT. A descrição apresentada abrange ambas as extremidades da cadeia de distribuição: desde a forma como os sinais de vídeo são adquiridos e processados até ao modo como eles são entregues ao cliente, passando pelos problemas e consequências que tais serviços podem ter na rede. O principal objectivo deste trabalho é contribuir para compreender se é possível criar em Portugal um novo operador onde o core business seja a distribuição de vídeo utilizando apenas serviços OTT

Intelligent Circuits and Systems

ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.　 This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering

The Design of Ad Hoc Networks with Minimum Power and Maximum Battery Life

Multi-hop wireless ad hoc networks consist of terminals that can communicate without the support of fixed infrastructure. Nodes may communicate directly from source to destination or can use other nodes in the network as relays to facilitate a path from source to destination. These networks can be rapidly deployed and are therefore well suited to emergency service applications where fixed infrastructure has become unavailable or in situations where a temporary network is required. The essence of this type of network is the agreed co-operation between users and the underlying principle that each user is willing to make itself available as a relay for the overall benefit of the network group. In most cases the terminals in these networks are battery powered and so, to maximise the lifetime of, the network, the power consumption of each node needs to be managed. This thesis studies the optimum design of a multi-hop ad hoc network. Each layer is analysed and cross layering is considered where it is able to improve the performance. Four routing strategies for managing node usage are investigated; a minimum power routing scheme, a minimum power routing with a battery charge threshold scheme, a residual battery charge scheme and a proposed minimum power routing/maximum battery lifetime scheme. A network model has been developed to evaluate these schemes and the results show that a network lifetime (defined as the time until the first node reaches zero battery charge) of 21 hours can be obtained using the proposed routing scheme which represents an improvement of 5% over the power aware routing scheme and the residual battery charge scheme, 31 % over the minimum power routing with a battery charge threshold scheme, and 133% over the minimum power routing scheme. Space, frequency and time division multiple access schemes are analysed for supporting multiple simultaneous transmissions in the network. Space division multiplexing allows multiple access without affecting the bandwidth or data rate, but five to nine simultaneous routes can be supported. A time division scheme is considered the best solution when guaranteed access is required by all nodes, but this reduces the maximum bit rate per user. The throughput per unit time in a multi-hop route using a single frequency channel varies inversely with the number of hops. A novel cross layer scheme is proposed that selects the modulation order to match the number of hops in a route to maximise the throughput per unit time. Simulation results for this scheme show that this can improve the throughput on 52% of the routes using a proposed routing scheme, but the extra power required for the higher order modulation reduces the network lifetime by 14%. A total network design solution is presented, including both the transmission and signalling subsystems that shows how the novel routing and cross layer features proposed in the thesis can be implemented