Smart resource allocation for improving QoE in IP Multimedia Subsystems

[EN] IP Multimedia Subsystem (IMS) is a robust multimedia service. IMS becomes more important when delivering multimedia services. Multimedia service providers can benefit from IMS to ensure a good QoE (Quality of Experience) to their customers with minimal resources usage. In this paper, we propose an intelligent media distribution IMS system architecture for delivering video streaming. The system is based primarily on uploading a multimedia file to a server in the IMS. Later, other users can download the uploaded multimedia file from the IMS. In the system, we also provide the design of the heuristic decision methods and models based on probability distributions. Thus, our system takes into account the network parameters such as bandwidth, jitter, delay and packet loss that influence the QoE of the end -users. Moreover, we have considered the other parameters of the energy consumption such as CPU, RAM, temperature and number connected users that impact the result of the QoE. All these parameters are considered as input to our proposal management system. The measurements taken from the real test bench show the real performance and demonstrate the success of the system about ensuring the upload speed of the multimedia file, guaranteeing the QoE of end users and improving the energy efficiency of the IMS.This work has been partially supported by the "Ministerio de Ciencia e Innovation", through the "Plan Nacional de I+D+i 2008-2011" in the "Subprograma de Proyectos de Investigation Fundamental", project TEC2011-27516, and by the Polytechnic University of Valencia, though the PAID-15-11 multidisciplinary projects.Canovas Solbes, A.; Taha, M.; Lloret, J.; Tomás Gironés, J. (2018). Smart resource allocation for improving QoE in IP Multimedia Subsystems. Journal of Network and Computer Applications. 104:107-116. https://doi.org/10.1016/j.jnca.2017.12.020S10711610

Integrating legacy mainframe systems: architectural issues and solutions

For more than 30 years, mainframe computers have been the backbone of computing systems throughout the world. Even today it is estimated that some 80% of the worlds' data is held on such machines. However, new business requirements and pressure from evolving technologies, such as the Internet is pushing these existing systems to their limits and they are reaching breaking point. The Banking and Financial Sectors in particular have been relying on mainframes for the longest time to do their business and as a result it is they that feel these pressures the most. In recent years there have been various solutions for enabling a re-engineering of these legacy systems. It quickly became clear that to completely rewrite them was not possible so various integration strategies emerged. Out of these new integration strategies, the CORBA standard by the Object Management Group emerged as the strongest, providing a standards based solution that enabled the mainframe applications become a peer in a distributed computing environment. However, the requirements did not stop there. The mainframe systems were reliable, secure, scalable and fast, so any integration strategy had to ensure that the new distributed systems did not lose any of these benefits. Various patterns or general solutions to the problem of meeting these requirements have arisen and this research looks at applying some of these patterns to mainframe based CORBA applications. The purpose of this research is to examine some of the issues involved with making mainframebased legacy applications inter-operate with newer Object Oriented Technologies

Prospects of peer-to-peer SIP for mobile operators

Tämän diplomityön tarkoituksena on esitellä kehitteillä oleva Peer-to-Peer Session Initiation Protocol (P2PSIP), jonka avulla käyttäjät voivat itsenäisesti ja helposti luoda keskenään puhe- ja muita multimediayhteyksiä vertaisverkko-tekniikan avulla. Lisäksi tarkoituksena on arvioida P2PSIP protokollan vaikutuksia ja mahdollisuuksia mobiilioperaattoreille, joille sitä voidaan pitää uhkana. Tästä huolimatta, P2PSIP:n ei ole kuitenkaan tarkoitus korvata nykyisiä puhelinverkkoja. Työn alussa esittelemme SIP:n ja vertaisverkkojen (Peer-to-Peer) periaatteet, joihin P2PSIP-protokollan on suunniteltu perustuvan. SIP mahdollistaa multimedia-istuntojen luomisen, sulkemisen ja muokkaamisen verkossa, mutta sen monipuolinen käyttö vaatii keskitettyjen palvelimien käyttöä. Vertaisverkon avulla käyttäjät voivat suorittaa keskitettyjen palvelimien tehtävät keskenään hajautetusti. Tällöin voidaan ylläpitää laajojakin verkkoja tehokkaasti ilman palvelimista aiheutuvia ylläpito-kustannuksia. Mobiilioperaattorit ovat haasteellisen tilanteen edessä, koska teleliikennemaailma on muuttumassa yhä avoimemmaksi. Tällöin operaattoreiden asiakkaille aukeaa mahdollisuuksia käyttää kilpailevia Internet-palveluja (kuten Skype) helpommin ja tulevaisuudessa myös itse muodostamaan kommunikointiverkkoja P2PSIP:n avulla. Tutkimukset osoittavat, että näistä uhista huolimatta myös operaattorit pystyvät näkemään P2PSIP:n mahdollisuutena mukautumisessa nopeasti muuttuvan teleliikennemaailman haasteisiin. Nämä mahdollisuudet sisältävät operaattorin oman verkon optimoinnin lisäksi vaihtoehtoisten ja monipuolisempien palveluiden tarjoamisen asiakkailleen edullisesti. Täytyy kuitenkin muistaa, että näiden mahdollisuuksien toteuttamisten vaikutusten ei tulisi olla ristiriidassa operaattorin muiden palveluiden kanssa. Lisäksi tulisi muistaa, että tällä hetkellä keskeneräisen P2PSIP-standardin lopullinen luonne ja ominaisuudet voivat muuttaa sen vaikutuksia.The purpose of this thesis is to present the Peer-to-Peer Session Initiation Protocol (P2PSIP) being developed. In addition, the purpose of this thesis is to evaluate the impacts and prospects of P2PSIP to mobile operators, to whom it can be regarded as a threat. In P2PSIP, users can independently and easily establish voice and other multimedia connections using peer-to-peer (P2P) networking. However, P2PSIP is not meant to replace the existing telephony networks of the operators. We start by introducing the principles of SIP and P2P networking that the P2PSIP is intended to use. SIP enables to establish, terminate and modify multimedia sessions, but its versatile exploitation requires using centralized servers. By using P2P networking, users can decentralize the functions of centralized servers by performing them among themselves. This enables to maintain large and robust networks without maintenance costs resulted of running such centralized servers. Telecommunications market is transforming to a more open environment, where mobile operators and other service providers are challenged to adapt to the upcoming changes. Subscribers have easier access to rivalling Internet-services (such as Skype) and in future they can form their own communication communities by using P2PSIP. The results show that despite of these threats, telecom operators can find potential from P2PSIP in concurrence in adaptation to the challenges of the rapidly changing telecom environment. These potential roles include optimization of the network of the operator, but as well roles to provide alternative and more versatile services to their subscribers at low cost. However, the usage of P2PSIP should not conflict with the other services of the operator. Also, as P2PSIP is still under development, its final nature and features may change its impacts and prospects

CAP Limits in Telecom Subscriber Database Design

While the notion of a Distributed DBMS has been familiar to the IT industry for several decades, within telecom networks the subscriber data management based on DDBMS technology is a novel addition to a service provider's infrastructure. Service providers are used to telecom networks that are efficient, reliable and easy to maintain and operate, in part thanks to the node model used in designing such networks. A DDBMS spanning a large geographical area however incurs into distributed systems issues not previously seen in telecom networks. Identifying and delivering the right set of trade-offs that satisfies the service providers ’ needs while staying within the known physical bounds of a distributed system is therefore crucial if DDBMS are to conquer the subscriber management space within telecom networks. 1

Creation of value with open source software in the telecommunications field

Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200

Effective interprocess communication (IPC) in a real-time transputer network

The thesis describes the design and implementation of an interprocess communication (IPC) mechanism within a real-time distributed operating system kernel (RT-DOS) which is designed for a transputer-based network. The requirements of real-time operating systems are examined and existing design and implementation strategies are described. Particular attention is paid to one of the object-oriented techniques although it is concluded that these techniques are not feasible for the chosen implementation platform. Studies of a number of existing operating systems are reported. The choices for various aspects of operating system design and their influence on the IPC mechanism to be used are elucidated. The actual design choices are related to the real-time requirements and the implementation that has been adopted is described. [Continues.

Enabling technologies for decentralized interpersonal communication

In the recent years the Internet users have witnessed the emergence of Peer-to-Peer (P2P) technologies and applications. One class of P2P applications is comprised of applications that are targeted for interpersonal communication. The communication applications that utilize P2P technologies are referred to as decentralized interpersonal communication applications. Such applications are decentralized in a sense that they do not require assistance from centralized servers for setting up multimedia sessions between users. The invention of Distributed Hash Table (DHT) algorithms has been an important, but not an inclusive enabler for decentralized interpersonal communication. Even though the DHTs provide a basic foundation for decentralization, there are still a number of challenges without viable technological solutions. The main contribution of this thesis is to propose technological solutions to a subset of the existing challenges. In addition, this thesis also presents the preliminary work for the technological solutions. There are two parts in the preliminary work. In the first part, a set of DHT algorithms are evaluated from the viewpoint of decentralized interpersonal communication, and the second part gives a coherent presentation of the challenges that a decentralized interpersonal communication application is going to encounter in mobile networks. The technological solution proposals contain two architectures and two algorithms. The first architecture enables an interconnection between a decentralized and a centralized communication network, and the second architecture enables the decentralization of a set of legacy applications. The first algorithm is a load balancing algorithm that enables good scalability, and the second algorithm is a search algorithm that enables arbitrary searches. The algorithms can be used, for example, in DHT-based networks. Even though this thesis has focused on the decentralized interpersonal communication, some of the proposed technological solutions also have general applicability outside the scope of decentralized interpersonal communication