Ella Pereira

Video Streaming: H.264 and the Internet of Things

Video data has been growing in importance over the last decade, and it is expected to exceed all other forms of networked data in for some time. This is also the case for the specific scenario of mobile data, where more than 60% of traffic globally will be video data. As the future Internet will encompass traffic from the Internet of Things, including low power personal devices in low quality media networks, any real time video data with source or destination in such a network will need to be encoded accordingly. In this paper we consider a few encoding options from the H.264 standard with the aim of analysing their suitability for encoding IoT related video data. We discuss the relative benefits of single layer (non-scalable) and scalable video encoders and make recommendations based on the limited capabilities of the IoT devices and transmission channels.

Evaluating security mechanisms implemented on public Platform-as-a-Service cloud environments case study: Windows Azure

The security risks of cloud computing and ambiguity of security mechanisms implemented on an on-demand cloud service like Platform-as-a-Service (PaaS), continues to raise concerns in cloud consumers. These risks clearly affect the adoption of the potentials offered by provisioning of computer resources of this scale. Examining an on-demand Platform-as-a-Service public cloud environment, this paper focuses on the security controls and mechanisms implemented on each component of Windows Azure. Using a security framework which consists of industry standard controls to evaluate its security offerings, this study attempts to understand how its security controls and implementations meet the needs of consumers in identity management, access management and virtualization security in the development of web based applications hosted on the cloud.

Mapping Security Requirements to Identify Critical Security Areas of Focus in PaaS Cloud Models

Information Technology experts cite security and privacy concerns as the major challenges in the adoption of cloud computing. On Platform-as-a-Service (PaaS) clouds, customers are faced with challenges of selecting service providers and evaluating security implementations based on their security needs and requirements. This study aims to enable cloud customers the ability to quantify their security requirements in order to identify critical areas in PaaS cloud architectures were security provisions offered by CSPs could be assessed. With the use of an adaptive security mapping matrix, the study uses a quantitative approach to presents findings of numeric data that shows critical architectures within the PaaS environment where security can be evaluated and security controls assessed to meet these security requirements. The matrix can be adapted across different types of PaaS cloud models based on individual security requirements and service level objectives identified by PaaS cloud customers.

Client Buffering Considerations for Video Streaming

An important issue in the performance of Video Streaming systems is the data transmission mechanism used by the server. Streaming servers can use a variety of techniques, which have an impact on a number of metrics associated with the performance and the quality of the video presentation. One of the related issues is the assignment of buffer space at the client in order to hold data that has arrived earlier than their playback time. In this article, we conduct a number of experiments with MPEG-4 compressed video, in order to obtain buffering occupancy values for various transmission mechanisms. In particular, we consider some of the mechanisms used by YouTube video servers, and contrast their performance with that of other mechanisms.

Exploring dependability issues in IoT applications

We have been witnessing a formation of a new technological marvel: Internet of Things. The Internet of Things (IoT) is driven by an expansion of the Internet through the inclusion of physical objects combined with an ability to provide smarter services to the environment as more data becomes available. This construction is able to combine in a particular operational entity all the bits and pieces of the world around us. This concept has been able to be integrated into various fields which includes the health care sector, transportation sectors, smart cities and various areas of human endeavor to make life a better and easy place for mankind. Hence, it is important to understand how to build IoT applications that are dependable and deliver what they are need to deliver. This paper explores dependability issues in Internet of Things applications by analyzing what is currently in the literature and conceptualizing the requirements of dependability in IoT application irrespective of their sizes and domain application and finally argues an importance why the issues of dependability needs to be explore and addressed in IoT applications

Ontology Driven Framework for Personal mHealth Application Development

Healthcare plays a significant role within a Smart city environment. Technology provides unprecedented opportunities to improve the delivery, effectiveness and quality of care an individual receives. This work focuses on the personalisation of Public healthcare services for services users, via the provision of mHealth applications. This paper describes the design considerations for developing a cloud-based framework to allow healthcare providers to develop some of the key applications for patients, personalised to their unique requirements.

Dynamic Adaptive Streaming over HTTP and Progressive Download: Comparative Considerations

Video data now accounts for over 50% of Internet traffic, and the widespread adoption of smart devices with high resolution screens has led to an increasing sharing of video content over social networks. The high availability of video content and of devices capable of displaying video data with high quality has facilitated this development. The high variability in available bandwidth to different clients on mobile and fixed networks implies that streams of different quality and thus bit rate should be used for different clients. Moreover, Internet congestion fluctuations suggest that the bandwidth available to each client will vary over time. As much of the Internet video has been based on progressive HTTP based downloading, which in its basic form is unable to adapt to bandwidth changes, the Dynamic Adaptive Streaming over HTTP - DASH - standard was proposed to enable adaptability of bit rate during a streaming session. Furthermore, this adaptation is managed by the clients to avoid server scalability issues. In this paper we consider a range of issues related to the performance of DASH and perform experiments that indicate the benefits associated with it.

Fault monitoring and detection of distributed services over local and wide area networks

Software development has evolved to incorporate the reusability of software components, enabling developers to focus on the requirements analysis without having to fully develop every component. Existing components that provide a given functionality can be reused by various applications. A parallel development has been the availability, through the World Wide Web, of data, transactions, and communications. These developments have led to the emergence of Web-services, collections of reusable code that use the Web communications paradigm for wider availability and communications between applications. In this context, with services coming and going, as well as possibly crashing, the issue of self-healing is of great relevance. How does an application learn that a remote service has become unavailable? In this paper we consider the issue of service failure detection and replacement, paying special attention to the relationship between the time it takes to find a replacement for a service, and the frequency of failure monitoring by the application

Predatory Search-based Chaos Turbo Particle Swarm Optimisation (PS-CTPSO): A new particle swarm optimisation algorithm for Web service combination problems

Abstract Web service combinatorial optimisation is an NP problem (that is, characterised by a nondeterministic polynomial time solution), based on the logical relationship between each service pair. As a consequence, obtaining the best Web service composition scheme is typically a complex task. In this article, we propose the Predatory Search-based Chaos Turbo Particle Swarm Optimisation (PS-CTPSO) algorithm, a chaotic particle swarm optimisation algorithm based on the predatory search strategy, which has significant potential to enhance the overall performance of the Autonomous Cloud. This is achieved by integrating a predatory search and cotangent sequence strategies with the particle swarm optimisation algorithm. More specifically, the PS-CTPSO algorithm identifies a feasible service via a global search, and subsequently, it obtains suitable candidate services within the corresponding chain. The different Web services are grouped into the same class, depending on whether they have the same input and output sets, thus reducing the number of combinations and improving the searching efficiency. In the initialisation phase, the PS-CTPSO component introduces the cotangent method, rather than a random one, which defines individual candidate services within the corresponding classes, creating a feasible service chain. In the update phase, a novel set of rules is used to perturb the velocities and positions of particles for assessing the ideal global search capabilities and adaptability. This effectively overcomes any premature problem, which commonly occurs in traditional PSO (Particle Swarm Optimisation) algorithms, and logic optimisation ensures the diversity of the final combination scheme. In this article, a prototype system (BestWS) is created, based on the directed graph generated by the logic relationships between Web services and the PS-CTPSO, Graph-Based Particle Swarm Optimisation (GB-PSO), Chaos Particle Swarm Optimisation (CS-PSO) and Chaos Particle Swarm Optimisation with Predatory Search strategy (PS-CSPSO) algorithms. The experimental results demonstrate that the cotangent sequence is more suitable than the chaotic one in the field of Web service combination optimisation. Furthermore, compared with the typical implementation of GB-PSO and PS-CSPSO, PS-CTPSO obtains better results, whilst attaining the global optimum with fewer iterations, and with an improved overall ergodicity.

Simulation tools in internet of things: a review

With the Internet of Things (IoT) paradigm promising to make major changes in various areas such as health care sector, transportation, smart farming, and smart cities to make life a better place for mankind, it is curtail that new systems built using this paradigm are properly designed and deliver reliable solutions. Use of simulation tools has a major role to play when IoT applications are designed and developed. However, IoT being relatively new paradigm, today major IoT researchers and developers find it difficult to select the right simulation tool for their research and requirement testing. This paper provides a comprehensive review of simulation tools to aid researchers and developers in selecting a right tool for their experiments when working with IoT applications.