Virtual Media Center: A Generic Architecture for Distributed VideoOnDemand Services

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Virtual Media Center A Generic Architecture for
Distributed Video-On-Demand Services
Department of Computer Science Engineering The
Chinese University of Hong Kong Master of Science
in Computer Science

• Date 30 April 2004
• Presented by Lee KaYan,Sunny
• Supervisor Prof. Michael R. Lyu

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Outline

• Motivation
• Related Work
• Virtual Media Center (VMC) Services
• Characteristics
• Technologies Used Web Service and CORBA
• System Architecture
• Implementation Details
• Future Works and Enhancements

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Motivation

• VOD is a bandwidth demand, the capacity of
  concurrent users is limited at present network
  equipment and technologies. A simple and
  efficiency server selection mechanism is needed
• Multimedia technologies such as compression,
  security and streaming protocol may change in the
  future. A framework to provide multimedia
  streaming service with the capability to
  adapting technologies change is needed
• To implement a application called Virtual Media
  Center under this framework

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Related Work

• Video-on-Demand (VOD)
• VOD is a service that allow users to view any
  video at any time and can use VCR-like functions
• Currently, the most popular and cheap technology
  for VOD is streaming over Internet
• Distributed Systems
• Common VOD architectures are distributed systems
  (DVOD)
• Distribution can be distributed system
  components, distributed streaming servers,
  distributed media content and distributed
  transmission source (stripping)
• Major solutions on DVOD
• Replicate strategy for video content
• Metrics based streaming server selection
• Set-Top box for buffering, caching and decryption

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Virtual Media Center (VMC) Services

• Video Streaming for VOD
• Real-time TV
• Real-time Web Cam
• Ad hoc streaming
• Auto server selection
• CORBA API
• Web service API

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Characteristics

• Distributed server architecture
• CORBA and Web service interface between server
• Integration of heterogeneous streaming technology
  and system
• By pass firewall
• Web user interface

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Technologies used Web Service and CORBA

• Why CORBA
• Middleware for heterogeneous network, computer
  hardware, operating system and programming
  language
• Best for interface between heterogeneous
  streaming server among different technology or
  content provider
• Drawback difficult to pass firewall in
  distributed environment

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Technologies Used CORBA and Web Service

• Why Web service
• Can pass firewall
• Best for interface between VMC and different
  content providers
• API for Web application
• Best for remote administration, monitoring etc.
• Provide catalogue to remote Web server

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System Architecture

• Roles in VMC
• System operator
• Content Provider
• Subscriber

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System Architecture

• Components in VMC
• Web server provide catalogue of media content
  to subscriber
• Database server provide information storage
• Streaming server provide multimedia content
  storage and streaming to subscriber

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System Architecture

• Scenario for VOD
• One central Web server for Internet access
• Many streaming server distributed in different
  geographic location for load balancing
• Subscribers are scattered in the Internet

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System Architecture

• Scenario for Real-time broadcast
• Use Audio/Video capture device such as Web Cam or
  TV turner card
• Web Cam or TV turner card can directly connected
  to streaming server

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System Architecture

• Scenario for Mobile user
• Remote Web server for Mobile device
• Consume catalogue from VMC through Web service
  API
• Choice best streaming server to delivery content
  by Remote Web server

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System Architecture

• Scenario for ad hoc multimedia streaming
• Ad hoc streaming source registration through Web
  service API
• Mobile user can real-time broadcast through
  wireless network
• Suitable for news broadcast, remote monitoring
  etc.

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System Architecture

• Scenario for local and remote servers
• CORBA within firewall
• Web service outside firewall
• For distributed streaming servers
• For independent content providers to contribute
  their own streaming servers

CORBA
Web Service
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System Architecture

• Scenario for real-time server selection
• Round-Trip Time (RTT)
• Server CPU utilization
• Server allocated bandwidth
• Server connected clients

CPU Utilization, Allocated Bandwidth and
Connected Clients
Round-Trip Time (RTT) information
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System Architecture

• Scenario for RTT Collection
• Optimal
• Between subscriber and streaming server
• Need subscriber accept mobile code or install RTT
  client
• Less optimal
• Between remote Web server and streaming server
• Remote Web server should located near subscriber
• Remote Web server responsible collect RTT and
  update to VMC periodically
• No mobile code or install RTT client to
  subscriber
• Best solution for mobile subscriber

Collect RTT periodically
RTT
RTT
RTT
RTT
Mobile code or RTT Client Installed
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System Architecture
A Generic Implementation Architecture
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System Architecture

• Logical Components

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Implementation
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Implementation Details

• Database structure in SQL server 2000

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Implementation Details

• In VMC server
• Web Server
• Windows 2003 Server
• Internet Information Server 6
• ASP.NET 1.1
• Web Service
• Visual Studio .NET 2003 C
• VMC Monitor (e.g. Collect RTT, server status
  etc.)
• Visual Studio .NET 2003 C
• .NET Remoting
• Database server
• SQL server 2000 MSDE version
• CORBA Naming Service
• omniORB Naming Service
• CORBA server object (for streaming server CPU
  utilization, allocated bandwidth and connected
  clients update)
• omniORB ORB VS.NET 2002 VC 7.0

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Implementation Details

• In Streaming server
• VOD service
• Microsoft Windows Media Server 9
• HTTP, MMS and RTSP
• Windows Media File format (.wmv)
• Real-time broadcast for TV and Web Cam
• Windows Media Encoder
• RTT Server
• Visual Studio .NET 2003 C
• .NET remoting
• Windows service
• CPU utilization, allocated bandwidth and
  connected clients update
• CORBA client omniORB ORB VS.NET 2002 VC 7.0
• Web service client VS.NET 2003 C

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Implementation Details

• Remote Web Server (for Wireless Mobile Device,
  Pocket PC version)
• Web Server
• Windows 2003 Server
• Internet Information Server 6
• ASP.NET 1.1
• Pocket PC requirement
• Microsoft Pocket PC 2003
• Windows Media Player 9
• Development and testing
• Visual Studio .NET 2003 C
• ASP.NET 1.1 Mobile Control
• .NET compact framework 1.1
• Pocket PC 2003 Emulator
• Pocket PC 2003 Phone Edition Emulator

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Implementation Details

• Programs in VMC server
• omniNames
• VMC_impl
• VMCMonitor

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Implementation Details

• Programs in streaming server
• WMSMonitor
• VSSMonitor
• Windows Service

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Implementation Details

• System Monitoring Tool
• S (s.exe)
• Syntax
• s ltserveridgt ltserveripgt
• e.g. s 0
• (0 means display the run-time information for all
  servers)

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Implementation Details

• Subscriber Interface
• VMC Home Page

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Implementation Details

• Subscriber Interface
• Catalogue Page

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Implementation Details

• Subscriber Interface
• Catalogue Page -
• Filter Functions

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Implementation Details

• Subscriber Interface
• Select Server Page

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Implementation Details

• Subscriber Interface
• VOD Session Page

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Advantage and Disadvantage

• Advantage
• CORBA and Web Service are well defined standard
• Independent to individual streaming technologies
• Web Interface for multiple devices PC, mobile
  notebook, Pocket, Palm, 3G phone or Smart phone
  etc.
• Real-time server selection
• RTT independent to any underlying network path
  selection algorithm and easy to implement
• Disadvantage
• Subscriber must installed a build in streaming
  player in Web browser to decode the target
  streaming
• Remote Web server must located nearest to
  subscriber to obtain the best RTT estimation for
  subscriber
• Streaming quality and concurrent connections are
  still limited to underlying bandwidth,
  compression technology and network equipment

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Future Works and Enhancements

• Implementation
• Interoperability between different ORB
• Mobile code for RTT client
• Native player install in subscriber device
• Test remote Web server for mobile device on real
  device
• Publish Web service on UDDI directory
• Testing
• Stress test on efficiency of RTT, CPU
  utilization, allocated bandwidth and connected
  clients
• Improvement of concurrent clients capacity on
  real-time server selection

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• End of Presentation
• Thanks !