TTM5 Networked Services and Multimedia Systems, advanced

1. TTM5Networked Services and Multimedia Systems, advanced Professor Peter Herrmann/ Postdoc Hien Nam Le Dept. Telematics (ITEM) University of Science and Technology (NTNU) hiennam@item.ntnu.no Rm A277

2. Introduction • Objective • This course shall give in-depth knowledge of principles, frameworks, and languages used for providing multimedia services over networks. • Contents • SOA & Multimedia Systems • Multimedia tools and frameworks for providing multimedia services • Framework and architecture • Service discovery and delivery • Deployment and management • Other issues: mobility, location-based, transaction services

3. Introduction • Recommended background • Communication - Services and Networks (TTM4100) • Access and Transport Networks (TTM4105) • Network Intelligence and Mobility (TTM4130) • Internet network architecture or equivalent (TTM4150). • Service and Resource Management (TTM 4128) • Assessment • Oral or writing examinations • Date: 03 Dec 2007 • Questions/requests • Email or walk-in rm A277

4. Schedule • 7 two-hours seminars

5. Topics • Introduction, review and background on multimedia systems and network services • Multimedia systems • Service-oriented architecture • Framework and architecture for developing multimedia services • Discovery and delivery of multimedia services • Deployment and management of multimedia services • Other issues • Location-based services, mobility, transaction services

6. An overview picture • Example • Develop a movie information service • Requirements

7. An overview picture Live Free or Die Hard John McClane takes on an Internet-based terrorist organization who is … Video clip Photos Text • Multimedia System • Storage • Presentation • Search and retrieval

8. An overview picture Development Multimedia System/ Application Tools, framework, architecture Interactions Clients

9. Service-oriented Computing/ Service-oriented Architecture Multimedia System/ Application Multimedia Services Service provider Interactions Services Binding Publishing Service registry Service clients Finding Clients Service Clients An overview picture

10. Course materials • Introduction, review and background • G. Coulouris, J. Dollimore, T. Kindberg: Distributed Systems: Concepts and Design, Chapter 15: Distributed Multimedia System • Mike P. Papazoglou: Service-Oriented Computing: Concepts, Characteristics and Directions. WISE 2003: 3-12 • Michael N. Huhns, Munindar P. Singh: Service-Oriented Computing: Key Concepts and Principles. IEEE Internet Computing 9(1): 75-81 (2005) • Jilles van Gurp, Anssi Karhinen, Jan Bosch: Mobile Service Oriented Architectures (MOSOA) • Additional reading • Donald F. Ferguson, Marcia L. Stockton: Service-oriented architecture: Programming model and product architecture. IBM Systems Journal 44(4): 753-780 (2005) • Mark Little: Transactions and Web services. Commun. ACM 10(43) (2003) • Gerald C. Gannod and Janet E. Burge and Susan D. Urban: Issues in the Design of Flexible and Dynamic Service-Oriented Systems. SDSOA '07: Proceedings of the International Workshop on Systems Development in SOA Environments

11. Course materials • Framework and architecture • Jia Zhang, Jen-Yao Chung: An open framework supporting multimedia web services. Multimedia Tools Appl. 30(2): 149-164 (2006) • Vassilios N. Koukoulidis, Mehul Shah: The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications. Multimedia Tools Appl. 28(1-2): 203-220 (2006) • Ahmet Uyar, Wenjun Wu, Hasan Bulut, Geoffrey Fox: Service-Oriented Architecture for Building a Scalable Videoconferencing System, in book "Service-Oriented Architecture - Concepts & Cases" published by Institute of Chartered Financial Analysts of India (ICFAI) University • Thanh, d. V.; Jorstad, I.; Dustdar, S.: Mobile Multimedia Collaborative Services . (2006) • Additional reading • Jia Zhang, Jen-Yao Chung: A SOAP-Oriented Component-Based Framework Supporting Device-Independent Multimedia Web Services. ISMSE 2002: 40-47

12. Course materials • Discovery and delivery • Yi Cui, Klara Nahrstedt, Dongyan Xu: Seamless User-Level Handoff in Ubiquitous Multimedia Service Delivery. Multimedia Tools Appl. 22(2): 137-170 (2004) • 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 • Ricky Robinson, Jadwiga Indulska: A Context-Sensitive Service Discovery Protocol for Mobile Computing Environments. ICMB 2005: 565-572 • Zhou Wang and Hend Koubaa: Discovering Multimedia Services and Contents in Mobile Environments. Handbook of Research on Mobile Multimedia

13. Course materials • Deploy and Management • Chih-Cheng Lo, Wen-Shyen E. Chen: Deploy Multimedia-on-Demand Services over ADSL Networks. IEEE Pacific Rim Conference on Multimedia 2002: 295-302 • Klara Nahrstedt, Wolf-Tilo Balke: A taxonomy for multimedia service composition. ACM Multimedia 2004: 88-95

14. Course materials • Other issues • Stefan Tai, Thomas A. Mikalsen, Eric Wohlstadter, Nirmit Desai, Isabelle Rouvellou: Transaction policies for service-oriented computing. Data Knowl. Eng. 51(1): 59-79 (2004) • Minsoo Lee, Gwanyeon Kim, Sehyun Park, Sungik Jun, Jaehoon Nah, Ohyoung Song: Efficient 3G/WLAN Interworking Techniques for Seamless Roaming Services with Location-Aware Authentication. NETWORKING 2005: 370-381 • Zhiwen Yu and Daqing Zhang: Middleware Support for Context-Aware Ubiquitous Multimedia Services. Handbook of Research on Mobile Multimedia.

15. Multimedia Services over Networks Review/background Framework/ Architecture Service provider Delivery Bind Publish Deployment/ Management Multimedia system Service registry Service client Find/discovery Issues: Transactions/mobility/locations

16. Distributed Multimedia Systems Chapter 15 – CDK book Slides

17. Video camera and mike Local network Local network Wide area gateway Video Digital server TV/radio server A distributed multimedia system • Applications: • non-interactive: net radio and TV, video-on-demand, e-learning, ... • interactive: voice &video conference, interactive TV, tele-medicine, multi-user games, live music, ... Figure 15.1

18. Learning objectives • To understand the nature of multimedia data and the scheduling and resource issues associated with it. • To become familiar with the components and design of distributed multimedia applications. • To understand the nature of quality of service and the system support that it requires. • To explore the design of a state-of-the-art, scalable video file service; illustrating a radically novel design approach for quality of service.

19. Multimedia in a mobile environment • Applications: • Emergency response systems, mobile commerce, phone service, entertainment, games, ...

20. At the right timeand in the right quantities Characteristics of multimedia applications • Large quantities of continuous data • Timely and smooth delivery is critical • deadlines • throughput and response time guarantees • Interactive MM applications require low round-trip delays • Need to co-exist with other applications • must not hog resources • Reconfiguration is a common occurrence • varying resource requirements • Resources required: • Processor cycles in workstations • and servers • Network bandwidth (+ latency) • Dedicated memory • Disk bandwidth (for stored media)

21. Application requirements • Network phone and audio conferencing • relatively low bandwidth (~ 64 Kbits/sec), but delay times must be short ( < 250 ms round-trip) • Video on demand services • High bandwidth (~ 10 Mbits/s), critical deadlines, latency not critical • Simple video conference • Many high-bandwidth streams to each node (~1.5 Mbits/s each), high bandwidth, low latency ( < 100 ms round-trip), synchronised states. • Music rehearsal and performance facility • high bandwidth (~1.4 Mbits/s), very low latency (< 100 ms round trip), highly synchronised media (sound and video < 50 ms).

22. System support issues and requirements • Scheduling and resource allocation in most current OS’s divides the resources equally amongst all comers (processes) • no limit on load • \ can’t guarantee throughput or response time • MM and other time-critical applications require resource allocation and scheduling to meet deadlines • Quality of Service (QoS) management • Admission control: controls demand • QoS negotiation: enables applications to negotiate admission and reconfigurations • Resource management: guarantees availability of resources for admitted applications • real-time processor and other resource scheduling

23. Data rate Sample or frame (approximate) frequency size Telephone speech 64 kbps 8 bits 8000/sec CD-quality sound 1.4 Mbps 16 bits 44,000/sec Standard TV video 120 Mbps up to 640 x 480 24/sec (uncompressed) pixels x 16 bits Standard TV video 1.5 Mbps variable 24/sec (MPEG-1 compressed) HDTV video 1000–3000 Mbps up to 1920 x 1080 24–60/sec (uncompressed) pixels x 24 bits HDTV video 10–30 Mbps variable 24–60/sec MPEG-2 compressed) Characteristics of typical multimedia streams Figure 15.3

24. PC/workstation PC/workstation Windowsystem Camera Component Bandwidth Latency Loss rate Resources required K H G A Codec Codec Out: 10 frames/sec, raw video Zero Camera L B Microphones 640x480x16 bits Mixer Network connections A Codec In: 10 frames/sec, raw video Interactive Low 10 ms CPU each 100 ms; Screen C Video file system Video store M D Out: MPEG-1 stream 10 Mbytes RAM Codec : multimedia stream Window system White boxes represent media processing components, many of which are implemented in software, including: B Mixer In: 2 44 kbps audio Interactive Very low 1 ms CPU each 100 ms; Out: 1 44 kbps audio 1 Mbytes RAM codec: coding/decoding filter mixer: sound-mixing component H Window In: various Interactive Low 5 ms CPU each 100 ms; system Out: 50 frame/sec framebuffer 5 Mbytes RAM K Network In/Out: MPEG-1 stream, approx. Interactive Low 1.5 Mbps, low-loss connection 1.5 Mbps stream protocol L Network In/Out: Audio 44 kbps Interactive Very low 44 kbps, very low-loss stream protocol connection Typical infrastructure components for multimedia applications • This application involves multiple concurrent processes in the PCs • Other applications may also be running concurrently on the same computers • They all share processing and network resources Figures 15.4 & 15.5

25. The QoS manager’s task Figure 15.6

26. QoS Parameters Bandwidth • rate of flow of multimedia data Latency • time required for the end-to-end transmission of a single data element Jitter • variation in latency :– dL/dt Loss rate • the proportion of data elements that can be dropped or delivered late

27. Admission control Admission control delivers a contract to the application guaranteeing: For each computer: • cpu time, available at specific intervals • memory Before admission, it must assess resource requirements and reserve them for the application • Flow specs provide some information for admission control, but not all - assessment procedures are needed • there is an optimisation problem: • clients don't use all of the resources that they requested • flow specs may permit a range of qualities • Admission controller must negotiate with applications to produce an acceptable result • For each network connection: • bandwidth • latency • For disks, etc.: • bandwifth • latency

28. Resource management • e.g. for each computer: • cpu time, available at specific intervals • memory • Scheduling of resources to meet the existing guarantees: Fair scheduling allows all processes some portion of the resources based on fairness: • E.g. round-robin scheduling (equal turns), fair queuing (keep queue lengths equal) • not appropriate for real-time MM because there are deadlines for the delivery of data Real-time scheduling traditionally used in special OS for system control applications - e.g. avionics. RT schedulers must ensure that tasks are completed by a scheduled time. Real-time MM requires real-time scheduling with very frequent deadlines. Suitable types of scheduling are: Earliest deadline first (EDF) Rate-monotonic

29. Source Targets High bandwidth Medium bandwidth Low bandwidth Scaling and filtering • Scaling reduces flow rate at source • temporal: skip frames or audio samples • spatial: reduce frame size or audio sample quality • Filtering reduces flow at intermediate points • RSVP is a QoS negotiation protocol that negotiates the rate at each intermediate node, working from targets to the source. Figure 15.9

30. Tiger Clients Network Tiger design goals (self-study) • Video on demand for a large number of users • Quality of service • Scalable and distributed • Low cost hardware • Fault tolerant

31. Youtube www.youtube.com • Supports the delivery of over 100 million videos per day • That is 4.167.000 per hour, 69.000 per minut, 1.150 per second • The team: 2 sysadmins, 2 scalability software architects 2 feature developers, 2 network engineers, 1 DBA. • What's essential to your service and prioritize your resources and efforts around those priorities • Keep it simple! Simplicity allows you to re-architect more quickly so you can respond to problems • http://highscalability.com/youtube-architecture

32. What is a Multimedia System? • A system that involves: • Generation: production/authoring tools • Representation: compression and formats • Storage: file system design • Transmission: networking issues, QoS • Search and retrieval: database management • Delivery: service design, QoS of multimedia information

33. Service-oriented Architecture • What is a service? • A Windows Service? • RPC Locator, EventLog, DHCP Client, • Software Service? • Distribution Service, Alert Service • Security Service, Log Service • Business Service? • Common Operational Picture, Navigation • Accounts Receivable, Customers • A service is a unit of work done by a service provider to achieve desired end results for a service consumer.

34. Papers • Mike P. Papazoglou: Service-Oriented Computing: Concepts, Characteristics and Directions. WISE 2003: 3-12 • Michael N. Huhns, Munindar P. Singh: Service-Oriented Computing: Key Concepts and Principles. IEEE Internet Computing 9(1): 75-81 (2005) • Jilles van Gurp, Anssi Karhinen, Jan Bosch: Mobile Service Oriented Architectures (MOSOA) • Additional reading • Donald F. Ferguson, Marcia L. Stockton: Service-oriented architecture: Programming model and product architecture. IBM Systems Journal 44(4): 753-780 (2005) • Mark Little: Transactions and Web services. Commun. ACM 10(43) (2003) • Gerald C. Gannod and Janet E. Burge and Susan D. Urban: Issues in the Design of Flexible and Dynamic Service-Oriented Systems. SDSOA '07: Proceedings of the International Workshop on Systems Development in SOA Environments

35. Services… • Technology neutral • Invocation mechanisms (protocols, descriptions, discovery) should comply with accepted standard • Loosely coupled • Must not require knowledge at the service side • Support location transparency • Service can be discovered and invoked by clients irrespective of their locations • Simple and composite services

36. Loosely coupling • Outlet plug adapters • Standard???

37. SOA vs. Objects/components • Services represent complete business functions • Re-used • CD-player example • CD • Players • Object oriented • CD+Player • Other issues • Stateless service more scalable & reliable • Stateful service more efficiency • Itempotent request

38. Service-oriented Architecture • SOA is an architecture style whose goal is to achieve loose coupling among interacting software agents • Consumers and Providers are agents • Minimum difference of plug adaptors • We need • A small & simple interface to all participating agents • Descriptive messages constrained

39. How can we identify an SOA? • Descriptive message • Order service, not how to “cook” the service • Understandable protocols/messages • Look at the menu, do not describe the “food” • Extensibility • vs. restrictions • Discovery service

40. An overview picture • Example • Develop a movie information service • Requirements

41. Services oriented architecture - basic Service provider Bind Publish Service registry Service client Find/discovery

42. Service interfaces and implementation

43. Extened SOA • Basic SOA does not address • Management • Service orchestration • Transaction, security, … • Extended SOA

44. Extened SOA

45. Web services Internet protocols: HTTP, FTP XML messages vs. SOA definition? Service provider WSDL Bind Publish UDDI SOAP Service registry Service client Find/discovery

46. Web services