Design of an integrated environment for adaptive multimedia document presentation through real time monitoring

The retrieval of multimedia objects is influenced by factor such as throughput and maximum delay offered by the network, and has to be carried out in accordance with the specification of object relationships. Many current network architectures address QoS from a provider' s point of view and analyze network performance, failing to comprehensively address the quality needs of applications. The work presented in this paper concerns the development of an integrated environment for creation and retrieval of multimedia documents, that intends to preserve the coherence between the different media, even when the process is confronted with a temporary lack of communication resources. This environment implements a communication system that, address QoS from the application's point of view and can help in handling variations in network resources availability through a real-time monitoring over these object relationships

Signalling Transmission for Internet Television

Signalizace v sítích pracujících s internetovým protokolem (IP) je používána pro monitorování a řízení činnosti sítě. Tato práce se zabývá přenosem signalizace skrze IP sítě pro velké skupiny komunikujících prvků a navrhuje škálovatelné řešení, jak pro malá, tak pro velká vysílání internetových televize (IPTV). Hlavní přínos práce spočívá v návrhu algoritmů pro ustavení optimálního hierarchického stromu na základě dostupných zdrojů a s ohledem na geografickou a virtuální polohu jednotlivých stanic. Pro účely optimalizace byly použity jak simulace s parametry globální experimentální sítě Planetlab, tak byly navržené algoritmy a protokoly nasazeny do reálného provozu v této síti.A signalization in an Internet protocol environment is commonly used for monitoring quality of service and other parameters of a network. This thesis is involved in transmission of signalization through internet protocol networks and proposes scalable solution for small and even for large-scale internet television broadcasting. The main contribution of this thesis lies in design and validation of optimal hierarchical tree on the basis of resources assigned. This is done in respect to geographical distance, network distance of each particular member of the hierarchical structure. For the design of algorithms simulations and global experimental network were used.

Enhanced QoS for real-time multimedia delivery over the wireless link using RFID technology.

This thesis presents a Sensor Guided Wireless Adaptation Scheme (SGWAS) that works in a micromobility domain. SGWAS infers the reason of high packet loss in a realtime multimedia flow received by a mobile node in a wireless cell. Determining the reason of packet loss relies on information obtained from wireless sensors, specifically RFID devices scattered in the cell, to detect the location of the mobile node. If packet loss is due to wireless link congestion, then local rate adaptation is applied in the cell. However, if it is due to handoff or signal propagation effects, e.g. obstruction or attenuation, then rate adaptation is not performed. The source adapts its transmission rate if congestion occurs in the wired network. SGWAS helps improve the quality of service and avoids unnecessary rate adaptation. Simulation results demonstrate that SGWAS identifies the reason of high packet loss and performs rate adaptation only when needed.Dept. of Computer Science. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2006 .E58. Source: Masters Abstracts International, Volume: 45-01, page: 0352. Thesis (M.Sc.)--University of Windsor (Canada), 2006

A Scalability Scheme for the Real-Time Control Protocol

Recently, some problems related to using the Real-time Control Protocol (RTCP) in very large dynamic groups have arisen. Some of these problems are: feedback delay, increasing storage state at every member, and ineffective RTCP bandwidth usage, especially for receivers that obtain incoming RTCP reports through low bandwidth links. In addition, the functionality of some fields (e.g. packet loss fraction) in the Receiver Reports (RRs) becomes questionable as, currently, an increasing number of real-time adaptive applications are using receiver-based rate adaptive schemes instead of rate adaptation schemes based on the sender. This paper presents the design of a scalable RTCP (S-RTCP) scheme. S-RTCP is based on a hierarchical structure in which members are grouped into local regions. For every region, there is an Aggregator (AG) which receives the RRs sent by its local members. The AG extracts and summarises important information in the RRs, derives some statistics, and sends them to a Ma..