1 Multimedia services over networks Service provider Service client Service registry Publish Discovery Bind Multimedia system Review/background Framework/ Architecture Deployment/ Management Multimedia Services Delivery Transactions/mobility/locations

2 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: , (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: , (pdf)

3 Context-aware multimedia service Context information –Time –Location –Device capability –User preferences

4 Example Stopping vs. moving A B NTNU, Trondheim D: Distance of movement S: Speed of mobile host N b : Wireless bandwidth M: Amount of data transfered T b : Battery life-time T s < T m < T b

5 Context Management Context Aggregation Context Reasoning Context Learning Context Query User profiles Situation Query Service Clients Context Service

6 Context representation model

7 Context ontology User situation User Preference on Media Capability of media terminal

8 Context-aware multimedia architecture

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10 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

11 Agents Clients Server Client agentsServer agents Specifying the type of device Adaptive GUI components Prevent inter-component dependencies –Decoupling Reuse of interface components Dynamic restructured GUI Pros and Cons

12 GLIDE Hardware PDAs Cellphones Software J2ME-CDC CLDC

13 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 GUI created Handling Interactions

14 GLIDE development process PDAs Cellphones

15 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

16 Dynamic restructuring GUI Resources User’s behaviors From Interface To delivery content

17 Discovering multimedia services and contents Context awareness –When –Where Service discovery model –Broadcast –Centralized service directory –Distributed service directories

18 Broadcast model Pull vs Push

19 Centralized directory model 1.Locating directory 2.Service registration 3.Service lookup 4.Searching Examples: JINI, INS

20 Distributed service directories Service discovery is a service Interoperability Asynchronous service discovery Semantic service discovery

21 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

22 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

23 Context-sensitive query

24 Preference model and language

25 Application iCarpark

26 Application iCarpark - cont Issues: -Technologies -Location direction -RFID readers -On-car computers -Performances