1. E0262 - Multimedia Communications
Prof. Pallapa Venkataram,
Electrical Communication Engineering,
Indian Institute of Science,
Bangalore – 560012, India
Multimedia Communications
2. E0262 - Multimedia Communications
Objectives
●
To know the networking evolution.
●
To understand the network types.
●
To discuss multimedia requirements in the
communication systems.
●
To understand the basics of a multimedia communication
system.
●
To illustrate multimedia networks.
●
To know the Internet protocol suite for multimedia
communications.
4. E0262 - Multimedia Communications
Network Topologies Evolution
●
LAN
– Linear topology
– Starwired
– Multisegment
– Backboneconnected
– Switchedbackbonet
●
WLAN
●
WAN
5. E0262 - Multimedia Communications
Multimedia Requirements
●
To develop schemes for multiaccess networks which can
provide performance guarantees.
●
To develop a distribute routeselection strategy for point
topoint networks.
●
Realtime multimedia applications require guaranteed
performance communication services, such as throughput,
delay, delay jitter and loss rate.
●
The characteristics of a source, such as peak and average
rate, are known at channel establishment time.
●
Channel parameters have to be predicted in live
continuous video sources.
6. E0262 - Multimedia Communications
Communication Service for Multimedia
●
Qualityofservice (QoS) support and group communication system:
– establishment and takedown of appropriately congured
channels;
– negotiation of QOS levels between endsystems, intermediate
systems, and network control; and
– control of the agreed QOS level
●
bandwidth, delay, delay jitter (variance), and reliability.
●
Audio/Video groups can:
– have static or dynamic memberships during their lifetime,
– have centrally (typically sender) or distributedly (typically receiver)
controlled membership,
– consist of members with homogeneous or be heterogeneous
characteristics and requirements.
7. E0262 - Multimedia Communications
Multimedia Communication System
●
Communication system A system or facility capable of
providing information transfer between persons and
equipment.
●
CDROM: “Compact disk readonly memory.”
●
ClientServer Model: A client makes a request and a
server fulfills that request.
●
Composite Video: Analog video signals can be broken
down into parts such as luminance (Black & White) and
chrominance (color).
8. E0262 - Multimedia Communications
Multimedia File types
●
Here are some examples of le types:
●
Text Files: .txt, .doc, .rtf
●
Audio Files: .au, .aif, .wav
●
Graphic files: .jpg, .gif, .tif, .bmp, .pict, .pcx
●
Moving video files: .qt, .mov, .avi
●
Animation: .fli, .flc
9. E0262 - Multimedia Communications
Multimedia Communication System
●
Interactive Multimedia Design
●
Interlacing
●
Interleaved
●
Linear Multimedia
●
NonInteractive Multimedia
●
Nonlinear Multimedia
●
Presentation Multimedia
●
Latency and Bandwidth
11. E0262 - Multimedia Communications
Multimedia Communication System
●
LAN Access Method
●
Routing
●
Frame and Packet Structures
●
Packet Discrimination
●
Identify packets that require special handling.
●
Be capable of accommodating those special requirements.
●
Bandwidth Requirement, Reservation and Conservation
●
High bandwidth and low latency
12. E0262 - Multimedia Communications
Multimedia Communication System Architecture
●
The ability to manage dynamically the achieved QoS of each service
component
●
The possibility for users to select some resources that best meet their
needs.
●
The possibility to interact with another user whose equipment has differing
characteristics.
●
The communications network must allow any user to select the service
components he/she wants:
●
The possibility for users to join in or withdraw from a communication
session according to certain policies, such as agreement of all interacting
partners before admitting a new user.
●
The possibility to set such quality of service parameters as the
synchronization tolerance between the service components, the echo
sensitivity, the burst sensitivity, and so on.
15. E0262 - Multimedia Communications
Multimedia Hardware/Software
●
Audio/Video Hardware
●
Digital Video (DV)
●
Analog to Digital devices
●
Builtin Hardware
●
Digital Video Software
●
Multimedia Software
19. E0262 - Multimedia Communications
Multimedia Internet Protocols
●
Multimedia over TCP
●
Multimedia over UDP
20. E0262 - Multimedia Communications
RTP
●
Realtime Transport Protocol (RTP) provides support for
the transport of realtime data such as video and audio
streams.
●
RTP needs support from lower layers that actually have
control over resources in switches and routers
●
RTP/RTCP provides functionality and control
mechanisms necessary for carrying realtime content.
●
RTP/RTCP itself is not responsible for the higherlevel
tasks like assembly and synchronization. These have to
be done at application level.
21. E0262 - Multimedia Communications
RTCP
●
RealTime Control Protocol extends RTP
●
In an RTP session, participants periodically send RTCP packets to convey
feedback on quality of data delivery and information of membership.
●
Packets defined for carrying control information:
– SR: Sender report, for transmission and reception statistics from
session participants that are
– active senders.
– RR: Receiver report, for reception statistics from session participants,
that are not active
– senders.
– SDES: Source description items, including CNAME
– BYE: Indicates end of participation
– APP: Application specific functions
22. E0262 - Multimedia Communications
Multimedia Internet Protocols
●
SAP & SDP
– Peer to peer communication, the concept of session.
●
SIP
– Signaling mechanisms that are necessary to establish a
session and to negotiate the parameters to be used in it,
such as codecs, media, location, etc.
●
MBONE Tools
– SDR, VIC, VAT and RAT, WB, NTE.
23. E0262 - Multimedia Communications
Multimedia Internet Protocols
●
RSVP
– Network control protocol
– Allows data receiver to request a special endtoend quality
of service for its data flows.
●
RTSP
– A clientserver multimedia presentation protocol to enable
controlled delivery of streamed multimedia data over IP
network.
– Aims to provide the same services on streamed audio and
video just as HTTP does for text and graphics.
24. E0262 - Multimedia Communications
Multimedia Communications
●
HighDensity File Transfers
●
Graphics File Transfers
●
Audio File Transfers
●
Video File Transfers
●
Audio Communication
●
ComputerBased Telephony
●
ComputerBased Audio Conferencing
●
Streaming Audio
●
Video Communication
●
Video Conferencing
●
Streaming Video