User-Centric Content Negotiation for Effective Adaptation Service in Mobile Computing

We address the challenges of building a good content adaptation service for mobile devices and propose a decision engine that is user-centric with QoS awareness, which can automatically negotiate for the appropriate adaptation decision to use in the synthesis of an optimal adapted version. The QoS-sensitive approach complements the lossy nature of the transcoding operations. The decision engine will look for the best trade off among various parameters in order to reduce the loss of quality in various domains. Quantitative methods are suggested to measure the QoS of the content versions in various quality domains. Based on the particular user perception and other contextual information on the client capability, the network connection, and the requested content, the proposed negotiation algorithm will determine a content version with a good aggregate score. We have built a prototype document adaptation system for PDF documents to demonstrate the viability of our approach.published_or_final_versio

A QoS framework for connection services in Parlay

Abstract Most applications using network connection services require information to be transferred within specific constraints (or Quality of Service). Parlay enables applications to access functionality of underlying networks while preserving network integrity. Connection service functionality of underlying networks is currently provided to applications by Parlay in the Call Control and Data Session Control SCFs. Parlay does not however provide access to the QoS functionality of connection services although this functionality may be provided by networks. This report presents the design, specification and simulation of a QoS framework for connection services provided by Parlay. The QoS framework provides applications with access to the QoS functionality of connection services in the underlying networks. The design is divided into 3 parts (or models): the object model (defines the objects that make up the QoS framework), the information model (deals with how objects specify QoS and mappings between different QoS specifications), and the interaction model (defines how objects interact). A formal, technology-independent specification of the QoS framework is presented using UML. The specification is composed using the three parts of the design. A simulation of the QoS framework presented in this report is also described to validate the framework. The simulation is a multi-threaded, distributed CORBA application implemented in JAVA (Java SDK version 1.5) and is based on the UML specification of the QoS framework. Details about the simulation design and implementation are summarised in this report. The QoS framework provides per-application, per-connection QoS support for Parlay’s connection services, supports existing and future Parlay connection services, follows existing Parlay design paradigms, and co-exists with and makes use of existing and future Parlay infrastructure. Parlay guidelines relating to permitted changes are followed strictly in the design of the QoS framework, which ensures the backward compatibility of Parlay if the QoS framework is added to the Parlay API. All Parlay design guidelines are also followed to allow for the easy integration of the QoS framework into the Parlay API. The simulation validates that the design of the QoS framework is: complete (in terms of specification), realistic, compatible with a standard Parlay implementation (JAVA and CORBA), and scalable (easy integration of new connection services)