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Multimedia services over networks. Framework/ Architecture. Review/background. Service provider. Multimedia Services Delivery. Bind. Publish. Deployment/ Management. Multimedia system. Service registry. Service client. Discovery. Transactions/ mobility/locations.
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Multimedia services over networks Framework/ Architecture Review/background Service provider Multimedia Services Delivery Bind Publish Deployment/ Management Multimedia system Service registry Service client Discovery Transactions/mobility/locations
Multimedia services delivery • Zhiwen Yu and Daqing Zhang: Middleware Support for Context-Aware Ubiquitous Multimedia Services. Handbook of Research on Mobile Multimedia. (pdf ). • Conor Muldoon, Gregory M. P. O'Hare, Rem W. Collier, Donnacha Phelan, Robin Strahan: Intelligent Delivery of Multimedia Content in a Device Aware Ubiquitous Environment. Multimedia Information Systems 2005: 131-145, (pdf) • Zhou Wang and Hend Koubaa: Discovering Multimedia Services and Contents in Mobile Environments. Handbook of Research on Mobile Multimedia (pdf) • Ricky Robinson, Jadwiga Indulska: A Context-Sensitive Service Discovery Protocol for Mobile Computing Environments. ICMB 2005: 565-572, (pdf)
Context-aware multimedia service • Context information • Time • Location • Device capability • User preferences
Example • Stopping vs. moving A B NTNU, Trondheim D: Distance of movement S: Speed of mobile host Nb: Wireless bandwidth M: Amount of data transfered Tb: Battery life-time Ts < Tm < Tb
Context Management Situation Context Aggregation Context Reasoning Query Context Learning Context Query Service Clients User profiles Context Service
Context ontology Capability of media terminal User Preference on Media User situation
Intelligent Delivery of Multimedia Content in a Device Aware Ubiquitous Environment • GLIDE • Generic Language of Interface DEvelopment • Context-aware ubiquitous environments • Enforce a coding structure on the implementation of interface components • Re-use and Extensibility • Enable GUI independence • Among interface components • Between interface components and agents • How? • Avoid object references • Use of agents
Agents • Prevent inter-component dependencies • Decoupling • Reuse of interface components • Dynamic restructured GUI Client agents Server agents Server Clients Adaptive GUI components Specifying the type of device Pros and Cons
GLIDE • Hardware • PDAs • Cellphones • Software • J2ME-CDC • CLDC
GLIDE framework • Factories • A class that returns an instance of a particular interface component • Interactions • Defines a dependency that a component has on another component or agent Composite object GLIDE Instance GUIcreated • Handling • Interactions
GLIDE development process PDAs Cellphones
GLIDE grammar • Factory • Which Java class whild be loaded to create service specific GUI components • Interacts • Define how the composite objects map interactions to entities • Entities can be components or agents
Dynamic restructuring GUI • Resources • User’s behaviors From Interface To delivery content
Discovering multimedia services and contents • Context awareness • When • Where • Service discovery model • Broadcast • Centralized service directory • Distributed service directories
Broadcast model Pull vs Push
Centralized directory model Examples: JINI, INS • Locating directory • Service registration • Service lookup • Searching
Distributed service directories • Service discovery is a service • Interoperability • Asynchronous service discovery • Semantic service discovery
A Context-Sensitive Service Discovery Protocol for Mobile Computing Environments • Discovery service • Query preferences • Allow tailoring query results • Query ranking when multiple resources are matched • Context-sensitive application • Context-aware • Adjust its behavior when the context changes • If resource discovery protocols are context-sensitive, then results are dependent upon the context of the query
Discovery framework • Persitent queries • Synchronous matching service • Asynchronous newly matching server • Elvin engine (asynchronous messaging system - should try) • Transient adversements • Information is meaningful only at the time of advertisement • Results are not stored • Sub-queries • Named queries
Application iCarpark - cont • Issues: • Technologies • Location direction • RFID readers • On-car computers • Performances