Multimedia Applications Instructor: Hamid R. Rabiee Spring 2013

Multimedia ApplicationsInstructor: Hamid R. Rabiee

Spring 2013

Outline

1. Digital TV Introduction to MHP

DVB

MHP

2. Voice Over IP Introduction to VOIP

Challenges of VOIP

IP telephony

3. IPTV Introduction to IPTV

Key features

IPTV components

4. Multimedia Conferencing Introduction to Multimedia Conferencing

Multimedia Conferencing Components

Types of Multimedia Conferencing

Communication in various network

topologies

Digital Media Lab - Sharif University of Technology2

Digital TV

Why digital TV?

Better image quality

More channels

Multiple audio channels

Subtitles

The whole new world of services


Digital TV Standards

Digital Video Broadcasting (DVB)

Satellite transmission standard (DVB-S)

Cable standard (DVB-C)

Terrestrial broadcast services standard (DVB-T)

Multimedia Home Platform standard (MHP)

Advanced Television Systems Committee (ATSC)

Terrestrial digital broadcasting standard (ATSC-T)

Cable distribution standard (ATSC-C)

Integrated Services Digital Broadcasting (ISDB)

Satellite broadcasting standard (ISDB-S)

Cable standard (ISDB-C) for cable TV networks

Terrestrial digital broadcasting standard (ISDB-T)

Terrestrial Sound Broadcasting (ISDB-TSB) for terrestrial broadcasting


Appendix A

Voice Over IP (VOIP)

Introduction to VOIP

What is VOIP? VoIP is the ability to make telephone calls and send faxes over IP-based data networks with a suitable quality

of service and superior cost/benefit. VOIP Components

Servers : For processing IP calls and manage interaction with PBX etc. End-point devices such as phones Media and VoIP gateways IP network

Why VOIP? Demand for Multimedia communication Demand for integration of Voice and Data networks Cost Reduction in long distance telephone calls

How VoIP works Continuously sample audio Convert each sample to digital form Send digitized stream across Internet in packets Convert the stream back to analog for playback

Challenge Voice transmission delay Call setup: call establishment, call termination, etc. Backward compatibility with existing PSTN (Public Switched Telephone Network)


Origins of VOIP

Internet Telephony software for multimedia PCs (1995)

Users frustrated by poor QoS, difficulty of use, lack of interoperability

Standards are critical for success

Coding/decoding (codec) between analog voice and digital packets

Locating the party you want to call

Signaling to set up, modify, tear down the voice call

Access to vertical services (call forwarding, 3-way calling, …)

Gateways to PSTN

Media routing, quality of service (QoS) left to other IP mechanisms (not

VoIP-specific)


VOIP: Goals and Benefits

Consolidation of voice, data on a single network

Simplify infrastructure, operations; provide bundled services

Support for intelligent terminals as well as phones

Increased flexibility

Multiple bit rates, multiple media types, richer signaling

Distinguish calls from connections (add/modify streams during call)

Separation of service control from switching/routing

Accelerate new service development, increase end-user control, evolve from

VoIP towards advanced services

Expansion of competition


Voice To/From IP

Analog

Digital

Voice

CODEC: Analog to Digital

Compress

Create Voice Datagram

Add Header(RTP, UDP, IP, etc)

N etw ork

Digital

Analog

Process Header

Re-sequence and Buffer Delay

Decompress

CODEC: Digital to Analog

N etw ork

Voice


NGN Architecture (Next-Generation Network)

Oriented towards application of VoIP (or VoATM) to large-scale public

networks

Focus on scalability, network control, support for traditional phones,

sophisticated gateway (GW) to the PSTN and its services

Media GW interfaces voice stream to PSTN trunk or phone line

Signaling GW allows signaling directly to SS7 network

Softswitch controls Media GWs and does call processing

Allows smaller, cheaper Media GWs (e.g., for individual homes)

Control via MGCP (Media Gateway Control Protocol) or H.248


Core Packet Core Packet NetworkNetwork

Softswitch

CustomerGateway

DSL or PacketCable

Access

NGNNGN ExampleVoice over DSL or Cable Modem

H323/SIPIP Phones,

PCs

SCP

Class 5 Switch

SS7 Signaling Network

PSTN

MGCPSS7

Gateway

Trunk GatewayVoice Streams

MG

CP

ISUP, TCAP

Can also use to interconnect PSTN clouds (long-distance), or PSTN switches (interoffice backbone)


Challenges of VOIP

Latency Latency is the time taken for a packet to arrive at its destination

Packet switching overhead Congestion

Latency may result in voice synchronization problems Jitter

Jitter is the delay experienced in receiving a packet when a packet is expected to arrive at the end point at a certain time

Bandwidth When bandwidth is shared between voice and computer data, certain bandwidth may have

to be allocated for voice communication on a network Packet loss

Packet loss in unavoidable It can be minimally tolerated in voice transmission

It should not, in the first place, distort the audio Reliability

Because the computer network is used, the reliability of the network will have an impact on the telephony service

In the analog telephone industry, reliability of 99.999 percent uptime is required The above is known as five nines

VoIP networks can achieve over 98 percent reliability ?


Challenges of VOIP (cont.)

Scalability Ability to add more telephony equipment as the company grows

Network bandwidth and other issues may have an effect on scalability Security

As VoIP uses the Internet, for example, it is vulnerable to the same type as security risks Hacking Denial of service Eavesdropping

Features IP telephony need to match and, in the long run, exceed the features provided by the

PSTN Call waiting Three way calling etc.

Interoperability IP telephony equipment manufactured by different vendors must be able to talk to

each other Standardized protocols are needed

Switch over cost The cost of migrating from legacy PBX to IP PBX


More in Appendix B

IP Telephony in Appendix C

Enterprise VoIP

IP PBX

Centrexor PBX

Softswitch

GWGW

Location A

Location B

GWGW

Many possible combinations of VoIP and circuit-switched telephony

IP phoneIP

phone

PSTN

NetworkCore IP


IPTV

Internet Protocol Television (IPTV)

IPTV (Internet Protocol television): the delivery of programming by video stream encoded as a series of IP packets.

IPTV can be free or fee-based and can deliver either live TV or stored video to the Television one addressed program at a time

Traditional Pay-Television: all programming is broadcast simultaneously and is available by tuning to the channel.

IPTV and Internet TV IPTV delivered to TV set, not PC IPTV is provided by a few large telecom providers Internet TV: anyone can create an endpoint and publish that on a global basis.

(YouTube) They are competitors

Introduction to IPTV


Why IPTV?

IPTV will provide better quality of service than

Internet streaming video

IPTV has the potential to offer an interactive,

customized experience

IPTV is effective whether you require a service to

delivery or not

Entertainment.

Advertising or information.

A hospitality system for hotels or hospitals.

Regular internal bulletins.

Up to date financial updates and market information.


Key Features of IPTV

Support for interactive TV: Two-way capabilities of IPTV systems allow

service providers to deliver interactive TV applications

Time shifting: IPTV in combination with a digital video recorder allows the

time shifting of programming content

Personalization: Allow end-users to personalize their TV viewing habits (what

& when they want to watch )

Low bandwidth requirements: Allow service providers to only stream the

requested (not every) channel to the user => netwrok operators can conserve

bandwidth on their network

Accessible on multiple devices: users can use their PCs and mobile devices as

well as television to access IPTV services


How Is IPTV Done?

Firstly we have to convert the incoming signals;

Terestrial TV,

Satellite TV,

FM and DAB Radio

into an IP format, MPEG2 and MPEG4.

To do this we us an IPTV Encoder.

The converted signals are then transmitted over the

LAN network with all the other data traffic, using

Multicast protocols.

Example shows, CCTV, VoD, Satellite and

Terrestrial TV being transmitted over the same

network.


Why Are Organizations Adopting IPTV?

Television and video services can easily be supplied to all computers on a

network, increasing staff access to news and company information.

The same infrastructure can be used no matter how many channels or viewing

devices are attached to the network. No special wiring or video distribution

design is required.

Consistently high video quality is maintained regardless of the number of

people watching TV and Video services.

Costs can be reduced by converging IPTV with existing data networks.

Prevent major internal disturbance through the use of existing networks


Appendix D

Overlay Network Service for IPTV

Overlay Network

IPTV Customer IPTV Video Server

Transport Network

IPTV Application

Overlay Node

IPTV ApplicationIPTV Application

consists of virtual network topologies on top of the physical network

responsible for forwarding and handling of IPTV application data

much more aggregate information and computing resources for clients or peers than from a limited number of centralized servers.

operated in organized and coherent way by the third party service provider or network provider to provide IPTV services.


Overlay Network Architecture

Network Provider 1 IPTV Server

BandwidthManager

Session Manager

Overlay Network

Network Provider 2

Overlay Node


Functions in IPTV Overlay Network

Control Function in IPTV Overlay Network

Perform session control and management for IPTV overlay network.

Establish and to maintain the network and system resources.

Virtual link among overlay nodes creates virtual topologies to deliver IPTV information.

Find optimal physical delivery paths for QoS and required network resource.

Multicast Function in IPTV Overlay Network

constructing different multicast trees depending on IPTV application parameters or application

classes.

supports efficient routing and resource usage by overlay multicast control.

In order to provide scalability for multicast function, hierarchical structure for overlay multicast will

be introduced in IPTV overlay networks.

Managing session to keep track of session configuration and maintenance for IPTV

service, and provide session initiation, release and management.


Control Functions for IPTV Overlay Multicast

IPTV Session Manager (ISM)ISM is involved in session configuration and maintenance

for IPTV service flows.

- Session initialization: ISM allocates ISID (IPTV Session ID) for new session.

- Session release: Session can be released as needed

- Session membership management

- Session status monitoring

IPTV Multicast Agent ( IMA )- Session join: each IMA contacts with Session Manager.

- Session leave: when an IMA wants leave the session

- Session maintenance: relay request and its response will be exchanged between the two IMAs periodically.

- Loop detection & avoidance

- Partitioning detection & recovering

- Parent switching

- IPTV Session status reporting


Appendix E

Multimedia Conferencing

Introduction

Multimedia Conferencing = an interactive tool that incorporates audio, video, and computing, and communications technologies to allow people in different locations To electronically collaborate face-to-face, in real time To share all types of information including data, documents, sound and picture.

What is needed? Efficient transport:

Enable real time transmission. Avoid sending the same content more than once. Best transport depends on available bandwidth and technology.

Audio processing: How to ensure Audio/Video Quality? How to Mix the streams?

Conference setup: Who is allowed to start a conference? How fast can a conference be initiated?

Security and privacy: How to prevent not-wanted people from joining? How to secure the exchanged content?

Floor control: How to maintain some talking order?


Steps to Choosing A MultimediaConferencing System1) Intended use for your system: how do you wish to use the equipment and whom are you going to talk to?

2) Number of sites: How many offices do you need to communicate with and what resources will each have at their disposal?

3) Number of participants per site: How many people do you want to participate in video calls at your various

locations? Do you want the same videoconferencing set-up for every location? Or, do you want to have a more deluxe system for your headquarters?

4) Size of your rooms: Where do you want to put the equipment? For example, is your current conference or meeting room big enough to add a system? Does your current meeting environment offer sufficient size, lighting and ancillary resources to accommodate an appropriate videoconferencing solution?

5) Connectivity: ISDN, BRI, PRI, T-1, Fractional T, ATM, Frame Relay, xDSL, Cable-modem? What connectivity best suits your internal communication requirements? Will the connection be dedicated to the conferencing system? What types of communications do you plan? Voice,video,data? (The type of communication will determine bandwidth requirements.) Also, what connectivity will remote sites make use of?

6) What type of systems or formats will you be calling: An ISDN system typically sends and receives voice and video data using the h.320 standard. An IP based (network) system typically communicates using the h.323 voice/video standard. You can only call between systems that subscribe to the same standard. However, gateway and bridge devices are available that will allow you to translate calls between the common standards. (Standards are defined by the International Telecommunications Union and are the same worldwide.)

7) Do you need data capability in addition to video & audio: Are you just looking to only see and talk to the other

people, or are you going to require the ability to do collaborative computing and share data? Do you want to share computer files and documents on screen? Will you need to show PowerPoint presentations?


Appendix F

How to videoconference in a Centralized Topology All register and send messages at a central point Central point forwards to others Tightly coupled: Some instances know all information about all participants at

all times

Advantages Simple to implement Single point of failure Appropriate for small to medium sized conferences Simple to manage and administer:

Allows access control and secure communication Allows usage monitoring Support floor control

Most widely used scenario No need to change end systems

Disadvantages High bandwidth consumption at center point

Must receive N flows High processing overhead at center point

Must decode N flows mix the flows and encode N flows With no mixing the central point would send Nx(N-1) flows

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All establish a connection to each other All can send directly to the others Each host will need to maintain N connections

Outgoing bandwidth: Send N copies of each packet simple voice session with 64kb/s would translate to 64xN

kb/s

Incoming bandwidth: If silence suppression is used then only active speakers send

data

Disadvantage In case of video lots of bandwidth might be consumed

Unless only active speakers send video End systems need to mix the traffic –more complex end systems

Advantage Security: simple! do not send data to members you do not trust

How to videoconference in a Full MeshTopology

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All establish a connection to the chosen mixer.

Outgoing bandwidth at the mixer end point: Send N copies of each packet simple voice session with 64kb/s would translate to 64xN

kb/s

Incoming bandwidth: If silence suppression is used then only active speakers send

data

Advantage Mostly used solution for three-way conferencing.

Disadvantage In case of video lots of bandwidth might be consumed

Unless only active speakers send video One of the end systems need to mix the traffic –more

complex end system.

How to videoconference in an End-Point-BasedTopology

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Benefits of Videoconferencing

Reduces Travel Expenses: There are numerous situations where you can save a lot of money on airfare and hotel costs, not to mention saving the loss in productivity from being out of the office.

Allows Multi-point Meetings Across Time Zones & International Boundaries: Videoconferencing lets you put together a meeting of various people, from different locations, for a common discussion.

Improves Effectiveness: Visually seeing the part during a videoconference is far more effective and meaningful than trying to describe it over the phone.

Increases Productivity: Websites and the Internet let us quicken the speed of communication. The use of videoconferencing will be the next driver for productivity because you will be able to keep in closer contact with customers. This closeness will lead to new ideas on how to speed up the development of new products and services.

Improves Communication & Reinforce Relationships: During a videoconference you can see

the facial expressions and body language of conference participants which are both important aspects of communication that are lost with a basic telephone call. Videoconferencing also allows the opportunity for more of your staff to have contact with your customers.


Appendix A


Digital TV Standards (cont.)

Table 1 – Comparison of Digital TV standards


DVB (Digital Video Broadcasting)

DVB (Digital Video Broadcasting) is a set of international open standards for digital television

DVB standards are maintained by the DVB Project (international industry consortium) and published by a Joint Technical Committee (JTC) of European Telecommunications Standards Institute (ETSI), European Committee for Electrotechnical Standardization (CENELEC) and European Broadcasting Union (EBU)

DVB standards are publicly available, free of charge at http://www.etsi.org and http://www.dvb.org

DVB standards are used in Europe; similar standards are ATSC (used in USA/North America), ISDB (used in Japan/South America) and DMB (used in China, Korea)


http://www.etsi.org/

http://www.dvb.org/

DVB (Digital Video Broadcasting) (cont.)

DVB standards define the physical layer and data link layer of the distribution system

DVB standards are based on MPEG-2 and MPEG-4 standards and all data is

transmitted in MPEG Transport Streams

Most important DVB standards are:

for satellite TV: DVB-S, DVB-S2

for terrestrial (aerial) TV: DVB-T, DVB-T2

for cable TV: DVB-C, DVB-C2

for handheld devices TV: DVB-H, DVB-SH

DVB has a conditional access system (DVB-CA) through Common Scrambling

Algorithm (DVB-CSA) and a physical Common Interface (DVB-CI)

DVB-S and DVB-C were ratified in 1994 and DVB-T in 1997


DVB-J

Special Java platform for digital television

JVM is part of OS A few interfaces

DAVIC Digital Audio Visual Council Payment interfaces Infrastructure interfaces Tuning interfaces

DVB Digital Video Broadcasting Extensions and limitations to Java-

interfaces Data access interfaces I/O-device interfaces Security interfaces

Java Basic interfaces: lang, util, beans... Graphical libraries: AWT, JMF Service interfaces: JavaTV

HAVi Home Audio Video Interoperability Display and user interface libraries


DVB-HTML

Digital Video Broadcasting – HyperText Markup Language HTML-like environment for television Technologies

xml, xhtml, css, dom, ECMAScript Pages or ”screens” are received from media carusel

Same way of thinking as in normal teletext service. Modern version of Teletext services

DVB-HTML services are very often called as supertext-tv services. It will replace the normal teletext services. New services possible but already launched applications are the same as in normal teletext but with

pictures Interactive services

DVB-HTML includes forms and links as a way to browse within service Forms makes it possible to build up somehow interactive content.

Need to remember that actual content for pages is received from media carusel. Few example services

News Extra information about tv-series or events Traffic jam information, bus timetables Subject specific portals Payment services

Order new services or products via television. (requires feedback channel)


Example of DVB-HTML page

<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE html SYSTEM "supertext.dtd"> <html> <head> <title>SM-Liiga</title> <link rel="stylesheet" href="styles1Column.css"/> </head> <body> <div class="title"> <span style="width: 200;">Tilastot

</span>

</div> <div class="main"> <br><span class="lihavointi"></span><br><br> <table> <tr> <td>SARJATAULUKKO</td> <td ></td> </tr> <tr> <td bgcolor="#cccccc"></td> </tr> ........


Multimedia Home Platform (MHP)

MHP is An open DVB standard which defines a whole set of technologies to implement

A set of Java APIs

A set of HTML document type definitions

A set of compatibility tests

Digital interactive multimedia services in the home

Includes home terminal (e.g., set-top box, TV set, or PC) and its peripherals and the in-home digital

network

Covers three application areas (i.e., enhanced broadcasting, interactive broadcasting, and Internet

access)

MHP goals

primary goal of the MHP is to enable the birth of horizontal markets for digital television and

multimedia services where there is open competition between content providers, network operators or

platform manufacturers at each level in the delivery chain.

Another goal is to exploit the potential for convergence between broadcasting, the Internet and

consumer electronics.


Multimedia Home Platform (MHP) (cont.)

Three main standards are related to MHP

MHP 1.0.x (1.0.0 – 1.0.3) The original MHP specification plus updates The most commonly deployed version of MHP

MHP 1.1.x Adds elements that were not finished in time for MHP 1.0.0 HTML support, stored applications, Internet client APIs, smart card APIs Still a work in progress Version 1.1.2 coming in April 2005

Globally Executable MHP (GEM) A subset of MHP 1.0.2 Designed to form the basis of other DTV middleware standards Currently used by OCAP, ACAP and ARIB B23

Also PVR for MHP specification (to be published April 2005) Adds support for PVR functionality to MHP receivers Compatible with OCAP PVR extensions


MHP profiles

+Java VM+DVB Java APIs+Basic media formats

(MPEG, GIF, JPEG, PNG, etc.)

+Broadcast transport protocols

+ Java APIs for return channel+ Protocols for return channel

HTTP 1.0, DNS, HTTPS mandatoryHTTP 1.1, DSMCC-UU optional

+ Java Internet client APIs+ Web browser & email client+ DVB-HTML (optional)

+ DVB-HTML (optional)+ App download over HTTP + Inner applications

+ Application storage+ Smart card APIs

Interactive Broadcast

profile

Enhanced Broadcast

profile

Internet Accessprofile

MHP 1.0.x MHP 1.1.x


Multimedia Home Platform (MHP) (cont.)

MHP architectural layers

Resources: MPEG processing, I/O devices, CPU, memory and a graphics system

System software: The system software uses the available resources in order to provide an abstract view of

the platform to the applications.

Applications : They are controlled by the application manager

API Interface: Defined by MHP as abstraction layer between different provider's applications and the

specific hardware and software on the terminal

Digital TV applications use APIs to access the actual resources of the receiver, including: databases,

streamed media decoders, static content decoders and communications.

Figure 1 – Basic MHP Architecture


MHP Applications

Information services super teletext, etc.

Show-related interactivity online quiz show, online

voting, etc.

Games

T-commerce and banking

Internet access

super teletext

Game

Banking


Remote controller, An MHP Device

MHP defines Arrow keys OK TXT Numbers 0-9 Color keys (in this order): red, green, yellow, blue

There are also other keys, that are not required

NorDig II suggests

Power ON / OFF

Programme UP / DOWN

Volume UP / DOWN

TV

Back


MHP Graphics

32-bit colors MHP minimum palette (140+48 colors)

Alpha channel 0%, 30%, 100% required by MHP If other values not supported, values are

rounded to these.

3 layers background video graphics

Java drawing primitives

Image formats

JPEG, GIF, PNG, MPEG I-Frame

Scaled video


MHP Layers

Background

Only one still image

MPEG I-Frame bitmap

Always full-screen

Opacity cannot be set

Video

MPEG-video from TV-stream

Video is scalable

Full screen, 1/4, 1/16

Other if device supports

Some devices supports multiple simultaneous video

streams, but this is not required by MHP-standard

Graphics

Graphic layer

Application graphics

Background

Video

Graphics


Appendix B


Challenges of VOIP (cont.)


Current VOIP Implementations


Enterprise Applications of VoIP

Leverage spare data-network capacity, minimize phone bills,

create platform for multimedia conferencing

H.323 and SIP both being deployed, softswitches and IP-PBX

options emerging, unclear which will prevail

Examples: Telcordia/SAIC (H.323), Telia (SIP)

Carrier-managed VPN networks last year from AT&T (H.323)

and Worldcom (SIP)

VoIP adoption slower than expected, partly due to plunging PSTN

long-distance prices, QoS concerns


VOIP Advanced Services

VoIP: natural platform for evolution to advanced services

Supports intelligent terminals and rich signaling

Separates calls from connections

Multimedia capabilities already in the protocols (SIP/H.323)

Removes bottleneck by separating call control from switching

Thus far, focus is almost entirely on voice

For many players (but not all), voice is the killer app

Solve the simpler problem first

This simplifies many network control issues, because of predictability of voice

bandwidth, traffic patterns

But current solutions are likely to require significant extensions to

accommodate more flexible advanced services


What’s Different About Advanced Services?

Flexibility in media streams, participants, “ownership”; service not pre-defined at

call setup

Multiple media per call, differing (and very wide range of) bandwidths

Dynamic re-configurability during call

Potential for multicast conferencing, streaming

Implications

Call admission control becomes more complex

Much less aggregation, localization of flows than with NGN voice

Usage, traffic patterns may be highly variable and hard to predict

New approaches to traffic engineering, resource allocation and network control will

be needed to address even a modest penetration of these new services


Appendix C


IP Telephony

Internet telephony uses the Internet protocol to send audio, video an data between two or

more users in the real time.

IP telephony is the integration and convergence of voice and data networks, services, and

applications.

The main motivation of development of IP Telephony is the cost saving & integrating new

services.

IP Telephony Standards H.323 standard

Session initiation protocol (SIP)

Media gateway to media controller protocol (MGCP) IP Telephony types

PC to PC

Phone-to-phone over IP

PC-to-Phone

Phone-to-PC


IP Telephony: PC-to-PC


IP Telephony: Phone-to-Phone Using Gateways


IP Telephony: Phone-to-Phone Using Adapter Gateways


IP Telephony: PC-to-Phone


Appendix D


Components of an IPTV System A National head-end - Origination point of network Broadcasts for transmission over the IP

network. Core networks - Usually an IP/MPLS network transporting traffic to the access network Access networks - Distributes the IPTV streams to the Digital Subscriber Line Access

Multiplexer (DSLAMs) Regional head-end – Origination point for local content Customer premises - Where the IPTV stream is terminated and viewed using a Set Top Box

or Computer.

Figure 2 – A typical IPTV system


Components of an IPTV System (cont.)

Hardware Blocks

BF5333 processor: Design for computational demands, power constraints of

embedded audio and video applications

Figure 3 - An IPTV system block diagram



Video Encoder ADV7171: converts digital CCIR-601 4:2:2 8- or 16-bit component video

data to an analogue baseband television signal compatible with worldwide standards

Audio Codec AD1836: A codec providing three stereo DACs and two stereo ADCs

Ethernet Interface SMSC LAN91C111 Chip: facilitate the implementation of a third

generation of Fast Ethernet connectivity solutions for embedded applications

Set-Top Box (STB): A dedicated computing device that serves as an interface

between a TV set and a broadband network

Main job = receive incoming IPTV signal & convert to a video signal that can be displayed in

TV

Allow viewers to select their video programming

Supports Web browsing, email & viewing email attachments, advanced multimedia codecs,

instant messaging, and real-time VOIP.



Software Blocks:

uClinux OS: this OS is loaded to memory and divided into kernel space (contain

system functions) and user space (contain application program)

Video Driver: Responsible for video applications

Audio Driver: Responsible for audio applications

Media Player: uses FFmpeg which is a complete solution to record, convert, &

stream audio and video

Streaming: STB creates connection to server for streaming the media

User Interface: An interface between user & IPTV STB to make STB interactive

with user


IPTV Issues

Encoding and Compression – The quality of a transmission can be affected from the source depending on the encoding technique and level of compression. Generally speaking increased compression leads to a poorer video quality but a smaller data stream. There is a tradeoff between bandwidth and compression level.

Jitter in IPTV transmission is defined as a short-term variation in the packet arrival time. Jitter is typically caused by network or server congestion. To help combat jitter, STB’s use buffers to smooth out the arrival times of the data packets. I the buffer overflows or underflows, at the STB, there is often a degradation of the video output.

Limited Bandwidth – Bandwidth availability is often an issue that affects the access network or the customers home network. When traffic utilizes the entire bandwidth, packets are dropped, leading to video quality degradation.

Packet Loss - Loss of IP packets may occur for multiple reasons: bandwidth limitations network congestion failed links transmission errors Packet loss usually presents a bursty behavior, commonly related to periods of network

congestion.


Appendix E


Additional capabilities of IPTV Overlay Network

Multicast Resource Management

Provide control function to multicast congestion problem

Multicast resource management

Re-negotiation function for additional resource requirements

Multiple data routing function for service/user requirements

Quickly detection of network problems for IPTV services

Provision of Intelligence for IPTV Service Features

Provision of dynamic creation and control function of IPTV Service Communities

QoS+Security+User’s Preference

Keywords/Program searching for IPTV Services


Overlay IPTV Multicast Control

Group membership management

Group Membership Control

Group Partitioning: Global group partitioning, Server group partitioning

Admission control

support QoS for IPTV services in overlay multicast network

resource control function for IPTV overlay network

Security for IPTV overlay multicast

Confidentiality and Integrity, Authenticity, and Availability.

Classified with some properties for architectures and algorithms for building secure

and scalable information dissemination services on IPTV overlay networks.


Appendix F


Multimedia Conferencing Applications

Business Reduce travel costs, improve use of executive time, speed up decision-making, keep

meetings brief and more focused than face-to-face meetings, enable top management to quickly and effectively communicate with employees sitting in multiple locations, provides an effective way of delivering cost-efficient training to individuals without the requirement to consistently travel to central locations.

Distance learning Teachers and students are able to see each other, share documents and discuss topics

together in a situation similar to a traditional classroom setting while they are in various countries.

Saving travel time and expenses, increasing an instructor’s audience, maintaining the ability for interaction between teachers and students

Telemedicine When a person needs medical advice but is unable to visit their personal physician or a

specialist. Videoconferencing enables patients to get the necessary information and expert guidance they need quickly and easily.

Telecommuting/Home office Users can save resources by meeting with clients and/or colleagues via videoconference.

This reduces travel expenses, while maintaining face-to-face contact. For a minimal cost, it is possible to set-up a fully functional videoconferencing system that works in a professional and reliable way from your home office.


Videoconferencing Codec Unit (End Points) = “BRAIN and HEART” of the Videoconferencing (multimedia conferencing) System It is also known as the Coder-Decoder. Function

1. It takes the video and audio from the camera and microphone 2. Compresses it down3. Transmits it over a network/digital phone line 4. Expands (or Decompresses) the incoming video and audio signal so that it

can be viewed on a display

Camera: The camera types range from a small desktop camera that sits on top of a computer monitor in a desktop system to a high-quality camera that has remote control pan, tilt and zoom (PTZ) features in a room-sized system.

Microphone : small microphones that attach to the Personal Computer in a

desktop conferencing unit, or a microphone designed to work best with a small group of people in a room-sized system.

Components of Multimedia Conferencing

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Components of Multimedia Conferencing(cont.) Video Monitor, XGA Monitor, Plasma Display,

LCD/DLP Projector These display devices are options that can be used to show

the images received from the videoconferencing codec. Videoconferencing systems can use multiple displaying

options. Desktop systems show the video in a small window on the computer monitor. Room-sized systems usually have one or two large video monitors and can display the local audience, as well as the remote audience.

Network Connection This is the connection that carries data between video

systems communicating with one another. The size of the connection and the ability to access it in a consistent manner, determines both video performance and quality of service. The connection can range from an ISDN phone line to a dedicated PRI/T-1 connection or access to a local area network.


Types of Multimedia Conferencing Systems

Desktop Multimedia Conferencing Systems: This technology can deliver full-motion Multimedia Conferencing from your PC. Desktop systems have been engineered to accommodate the

industry's requirements for standards-based videoconferencing. There are systems available that deliver high quality at a low

cost. These systems provide H.323 voice and video, as well as

applications sharing. They offer easy installation and many have no add-in boards to

install or bulky hardware to place on your desk.

Set-top Multimedia Conferencing Systems: Set-tops are complete Multimedia Conferencing systems designed to sit on a monitor. Useful in small boardrooms and other small group scenarios. Are often maintained on a cart, making it possible to roll them

around for use in different rooms. Have excellent video quality and work well with auxiliary

equipment, such as document cameras, to enhance videoconference presentations.


Types of Multimedia Conferencing Systems (cont.)

Integrated Multimedia Conferencing Systems: Integrated systems are group conferencing systems most often used in

conference rooms or classrooms with multiple participants.

This type of system usually consists of a centralized location

for wiring and processors to be routed. The main camera,

displays and peripheral video sources are usually mounted in

the main conferencing area.

These customized configurations are normally equipped with

multiple features and also allow for the videoconferencing

room to be used for other various functions as well.

Most integrated systems available today are capable of

connecting both H.320 (ISDN lines) and H.323 (IP/LAN).


Documents

Multimedia Applications Instructor: Hamid R. Rabiee Spring 2013