Statistical Assessment of IP Multimedia Subsystem in a Softwarized Environment: a Queueing Networks Approach

The Next Generation 5G Networks can greatly benefit from the synergy between virtualization paradigms, such as the Network Function Virtualization (NFV), and service provisioning platforms such as the IP Multimedia Subsystem (IMS). The NFV concept is evolving towards a lightweight solution based on containers that, by contrast to classic virtual machines, do not carry a whole operating system and result in more efficient and scalable deployments. On the other hand, IMS has become an integral part of the 5G core network, for instance, to provide advanced services like Voice over LTE (VoLTE). In this paper we combine these virtualization and service provisioning concepts, deriving a containerized IMS infrastructure, dubbed cIMS, providing its assessment through statistical characterization and experimental measurements. Specifically, we: i) model cIMS through the queueing networks methodology to characterize the utilization of virtual resources under constrained conditions; ii) draw an extended version of the Pollaczek-Khinchin formula, which is useful to deal with bulk arrivals; iii) afford an optimization problem focused at maximizing the whole cIMS performance in the presence of capacity constraints, thus providing new means for the service provider to manage service level agreements (SLAs); iv) evaluate a range of cIMS scenarios, considering different queuing disciplines including also multiple job classes. An experimental testbed based on the open source platform Clearwater has been deployed to derive some realistic values of key parameters (e.g. arrival and service times)

Study, Analysis and Modeling of IP Multimedia systems on next generation networks providing mobile and fixed multimedia services

Not availabl

Journal of Telecommunications and Information Technology, nr 3

kwartalni

Telecommunications Networks

This book guides readers through the basics of rapidly emerging networks to more advanced concepts and future expectations of Telecommunications Networks. It identifies and examines the most pressing research issues in Telecommunications and it contains chapters written by leading researchers, academics and industry professionals. Telecommunications Networks - Current Status and Future Trends covers surveys of recent publications that investigate key areas of interest such as: IMS, eTOM, 3G/4G, optimization problems, modeling, simulation, quality of service, etc. This book, that is suitable for both PhD and master students, is organized into six sections: New Generation Networks, Quality of Services, Sensor Networks, Telecommunications, Traffic Engineering and Routing

An Object Based Approach Towards the Automation of Office Procedures Using Intelligent Messages

Office support systems are used to automate routine office tasks. Since office tasks often require the cooperation of several office workers who may be physically dispersed, it is important to develop advanced communication systems that better facilitate collaborative and cooperative office work among office workers. In this thesis, we propose an approach to the construction of advanced communication systems in which messages are represented as objects that are “intelligent” and “active” and can therefore perform certain activities (such as interacting with various entities to collect data) and decisions (such as dynamically deciding which user to go to next) on their own. The system is called Intelligent Message System IMS. The major components of IMS are as follows: Intelligent Message Objects (IMO). These objects represent the actual intelligent objects of the system. System Mail Manager (SMM) which provides the users an interface to create, send, receive, and maintain IMOs. Intelligent Message Script Language (IMSL) is a language used to program IMOs. Office workers can delegate the responsibility for certain routine office tasks to an IMO and can therefore spend their time on more important activities. Thus, in addition to its theoretical contributions, this thesis provides a framework for building an advanced computer-based message system that increases productivity in an office environment. Each component of the IMS is explained in detail in the thesis. A variation of BNF formalism is used to define the syntax of IMSL while VDM is used to formally define the semantics of major functions of intelligent message objects. A number of examples are provided to illustrate the effectiveness of the IMS in automation of certain office tasks

VOICE OVER IP NETWORKS: QUALITY OF SERVICE, PRICING AND SECURITY

The growth of the Internet over the past decade together with the promise of lower costs to the customer has led to the rapid emergence of Voice over Internet Protocol (VoIP). As a real-time application in large scale packet switched networks, VoIP networks face many challenges such as availability, voice quality and network security. This dissertation addresses three important issues in VoIP networks: Quality of Service, pricing and security.In addressing Quality of Service (QoS), this dissertation introduces the notion of delay not exceeding an upper limit, termed the bounded delay (rather than the average delay), to measure the Quality of Service in VoIP networks. Queuing models are introduced to measure performance in terms of bounded delays. Closed form solutions relating the impact of bounding delays on throughput of VoIP traffic are provided. Traffic that exceeds the delay threshold is treated as lost throughput. The results addressed can be used in scaling resources in a VoIP network for different thresholds of acceptable delays. Both single and multiple switching points are addressed. The same notion and analysis are also applied on jitter, another important indicator of the VoIP QoSThis dissertation also develops a pricing model based on the Quality of Service provided in VoIP networks. It presents the impact of quality of VoIP service demanded by the customer on the transmission resources required by the network using an analytical approach. The price to be paid by the customer is based on the throughput meeting this criterion and the network transmission resources required. In particular, the impact of Quality of Service presented can be used in the design of VoIP networks in a way that would provide fairness to the user in terms of quality of service and price while optimizing the resources of the network at the same time.This dissertation also extends and applies the delay throughput analysis developed for VoIP networks in assessing the impact of risks constituted by a number of transportation channels, where the risk associated with each channel can be quantified by a known distribution. For VoIP security, this dissertation mainly focuses on the signaling authentication. It presents a networking solution that incorporates network-based authentication as an inherent feature. The authentication feature that we propose introduces a range of flexibilities not available in the PSTN. Since most calls will likely terminate on the network of another service provider, we also present a mechanism using which networks can mutually authenticate each other to afford the possibility of authentication across networks. Finally, this dissertation explores areas for future research that can be built on the foundation of research presented

The conceptual model of continuous improvement teamworking in retail banking operations: A mixed method

The thesis studied the development and implementation of the conceptual Continuous Improvement Teamworking (CIT) Model for strategic performance improvement in retail banking operations. The investigation using of a dominant qualitative to a Less-dominant quantitative approach as a mixed-method strategy revealed the importance of the CIT Model realised through the CTIO (Concern-Task-Interaction-Outcome) Problem-Solving Cycle. The CTIO Cycle is a variant form of the traditional Deming-Shewhart PDCA (Plan-Do-Check-Action) Cycle. With deregulation through financial reforms (FSRA Act) banking organizations are facing increased competition in the retail banking supply chain. There has been a new form and type of hybrid teamworking approach with banking organizations becoming virtual enterprises with sophistication of the financial management system and technological know how. With virtual meetings and interactive electronic communication people at work above their normal routine face-to-face teamworking activities are also having meetings, communication and sharing of information through a modernized Continuous Improvement Teamworking Approach using traditional teamworking, virtual team working (e-teamwork) and continuous improvement. In the mixed-method strategy used, the participant observation performed for 12 months in the retail banking operations confirmed the model. The two case studies implemented the CTIO Cycle with team members in two retail banking operations justified its problem-solving methodology to achieve strategic performance improvement of two key performance measures (sales referrals and customer satisfaction). The model tested in the two retail banking operations yielded desired and significant improvement. The 29 face-to-face interviews with managers using content analysis evaluated the validity of the model, and eventually the personal survey (149 questionnaires) with staff confirmed the reliability of the model. By doing the dominant qualitative research first, many hidden details and crucial parameters of the CIT Model were properly discovered by the researcher being closer to the scene. This would not have been successfully achieved if a quantitative methodology was firstly used. The findings provide insight into the triangulation of the knowledge domains of Continuous Improvement, teamworking and virtual teamworking from an integrated retail supply chain management perspective. The CIT Model is becoming increasingly important due to severe competition, economic down turn, increasing wave of technological know-how and quality information system. Considering the negative aspects of virtual teamworking, face-to-face teamworking is still being used with virtual interaction media. The research confirmed that teamworking in a modern service environment requires the use of both face-to-face and virtual interactions to deliver strategic productive performance of their retail supply chain. Thus, this study contributed for more than 29 papers with the Best Refereed Paper Award by the PhD Candidate at the Association of Qualitative Research (AQR) International Biennual Conference and two other awards from industry. This research is important to senior managers and first-line managers in improving the effectiveness and efficiency of teamwork as well as the overall operational activities of their businesses facing increasing competition, economic downturn, paradigm shift to e-Human Resources Management, e-quality management, e-Supply Chain Management, demanding customers for information system quality, and widespread waves of technology-driven innovations in information and communication technologies (ICT) in the retail banking supply chain

For the sake of development? Municipal government and local development in Emilia-Romagna and Turin (1945-1975)

This paper (1) examines two areas of Italy, with very different political subcultures and production systems,with the aim of making a comparative analysis of the role of local government policies in stimulating growth processesover the thirty-year post war period.Historians now agree that the policies of Italian local governments were a major factor in the processes ofeconomic growth and the spread of social services. They acted through a highly varied mix of policies, includingregulatory processes (town planning, coordinated local programming, etc.), operations enabling institutions to providethe local environment with specific public goods (industrial estates, business services etc.) as well as redistributionpolicies (i.e. the setting up and spread of local welfare systems and local tax systems).This influential steering role of local administrations, marked in some cases by the gradual inception ofspecific institutional authoritativeness, was not distributed uniformly over the whole of Italy and there were significantasymmetries between areas.A comparative analysis is made of the "Emilia-Romagna model" of local government, controlled by an ItalianCommunist hegemony in a context of small and medium sized firms, and the model of the city of Turin, which was basedon an industrial Ford model because of the presence of the Fiat factory. The two models are compared from theperspective of actors and their different interests. Our aim is to gauge the nature and intensity of the local institutionalactions that accompanied and promoted the processes of development

European Distance and E-Learning Network (EDEN). Conference Proceedings

Erasmus+ Programme of the European UnionThe powerful combination of the information age and the consequent disruption caused by these unstable environments provides the impetus to look afresh and identify new models and approaches for education (e.g. OERs, MOOCs, PLEs, Learning Analytics etc.). For learners this has taken a fantastic leap into aggregating, curating and co-curating and co-producing outside the boundaries of formal learning environments – the networked learner is sharing voluntarily and for free, spontaneously with billions of people.Supported by Erasmus+ Programme of the European Unioninfo:eu-repo/semantics/publishedVersio

Manager’s and citizen’s perspective of positive and negative risks for small probabilities

So far „risk‟ has been mostly defined as the expected value of a loss, mathematically PL, being P the probability of an adverse event and L the loss incurred as a consequence of the event. The so called risk matrix is based on this definition. Also for favorable events one usually refers to the expected gain PG, being G the gain incurred as a consequence of the positive event. These “measures” are generally violated in practice. The case of insurances (on the side of losses, negative risk) and the case of lotteries (on the side of gains, positive risk) are the most obvious. In these cases a single person is available to pay a higher price than that stated by the mathematical expected value, according to (more or less theoretically justified) measures. The higher the risk, the higher the unfair accepted price. The definition of risk as expected value is justified in a long term “manager‟s” perspective, in which it is conceivable to distribute the effects of an adverse event on a large number of subjects or a large number of recurrences. In other words, this definition is mostly justified on frequentist terms. Moreover, according to this definition, in two extreme situations (high-probability/low-consequence and low-probability/high-consequence), the estimated risk is low. This logic is against the principles of sustainability and continuous improvement, which should impose instead both a continuous search for lower probabilities of adverse events (higher and higher reliability) and a continuous search for lower impact of adverse events (in accordance with the fail-safe principle). In this work a different definition of risk is proposed, which stems from the idea of safeguard: (1Risk)=(1P)(1L). According to this definition, the risk levels can be considered low only when both the probability of the adverse event and the loss are small. Such perspective, in which the calculation of safeguard is privileged to the calculation of risk, would possibly avoid exposing the Society to catastrophic consequences, sometimes due to wrong or oversimplified use of probabilistic models. Therefore, it can be seen as the citizen‟s perspective to the definition of risk