engleski

Multimedia Session Reconfiguration for Application-level QoS Maintenance and Adaptation

One of the key requirements for evolution of communication networks is the provision of Quality of Service (QoS) support with respect to mobility. Addressing this requirement imposes numerous challenges on offering such a support for complex multimedia services. The approach proposed in this thesis complements the recent research efforts and introduces a model of multimedia session reconfiguration at the application level that dynamically maintains and adapts QoS for multimedia services. The proposed reconfiguration model is based on generic mobility events, which represent changes affecting QoS that are induced by terminal mobility and session mobility, and basic management operations, called reconfiguration primitives, which are applied in response. The set of required QoS management aspects is achieved through the identified functional model, which involves generalized network entities and the specified signaling procedures for facilitating multimedia session establishment and reconfiguration, QoS negotiation, network resource reservation, and event notification. To show a feasibility of the presented approach, the functional model is mapped to the ITU-T Next Generation Network (NGN) architecture. Discrete Event System Specification is used for a formal specification of the reconfiguration model and serves as the basis for its software implementation, simulation, and performance evaluation. Finally, the proposed model is applied in a case study that involves a laboratory prototype based on the 3GPP IP Multimedia Subsystem.

Multimedia service; Quality of Service (QoS); QoS maintenance; QoS adaptation; session mobility; terminal mobility; mobility events; session reconfiguration; Discrete Event System Specification (DEVS); simulation; performance evaluation; Next Generation Network (NGN); IP Multimedia Subsystem (IMS)

Disertacija je napisana i obranjena na engleskom jeziku sukladno odluci Fakultetskog vijeća Fakulteta elektrotehnike i računarstva Sveučilišta u Zagrebu. Naziv disertacije na hrvatskom jeziku glasi: "Rekonfiguracija višemedijske sjednice radi održavanja i prilagodbe kvalitete usluge na aplikacijskoj razini".