Multimedia Communications Student: Blidaru Catalina Elena.

Multimedia Communications

Student: Blidaru Catalina Elena

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.

Networking Infrastructure Evolution• Network deployment issues

Network Topologies Evolution• LAN

• Linear topology• Star-wired• Multisegment• Backbone-connected• Switched-backbonet

• WLAN• WAN

Source: http://samples.sainsburysebooks.co.uk/9780471656401_sample_382636.pdf

http://samples.sainsburysebooks.co.uk/9780471656401_sample_382636.pdf


Multimedia Requirements• To develop schemes for multi-access networks which can provide

performance guarantees.

• To develop a distribute route-selection strategy for point-to-point networks.

• Real-time 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.

Source: https://prezi.com/hcimhf8om-hv/multimedia-communication-in-business/http://samples.sainsburysebooks.co.uk/9780471656401_sample_382636.pdf

https://prezi.com/hcimhf8om-hv/multimedia-communication-in-business/




Communication Service for Multimedia• Quality-of-service (QoS) support and group communication system:

• establishment and take-down of appropriately congured channels;• negotiation of QOS levels between end-systems, 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.

Source: http://193.226.6.174/IT2002/pdf/L3.pdf

http://193.226.6.174/IT2002/pdf/L3.pdf

Multimedia Communication System• Communication system - A system or facility capable of providing

information transfer between persons and equipment.

• CD-ROM: “Compact disk read-only memory.”

• Client-Server 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).




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


http://193.226.6.174/IT2002/pdf/L3.pdf

Multimedia Communication System• Interactive Multimedia Design

• Interlacing

• Interleaved

• Linear Multimedia

• Non-Interactive Multimedia

• Nonlinear Multimedia

• Presentation Multimedia

• Latency and Bandwidth






Multimedia Application Environment

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

Source: http://multimediacommunication.blogspot.ro/

http://multimediacommunication.blogspot.ro/

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.




Multimedia Networks• Technical Issues

• Admission control• Scheduling• Resource management• Congestion control• Policing/Shaping




Multimedia Network Reference Model

Multimedia Hardware/Software• Audio/Video Hardware

• Digital Video (DV)

• Analog to Digital devices

• Built-in Hardware

• Digital Video Software

• Multimedia Software


Comparison of Stacks

INTERNET

Connection to Internet

Multimedia Internet Protocols

• Multimedia over TCP

• Multimedia over UDP


RTP• Real-time Transport Protocol (RTP) provides support for the

transport of real-time 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 real-time content.

• RTP/RTCP itself is not responsible for the higher-level tasks like assembly and synchronization. These have to be done at application level.

RTCP• Real-Time 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


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.


Multimedia Internet Protocols• RSVP

• Network control protocol• Allows data receiver to request a special end-to-end quality of service for its

data flows.

• RTSP• A client-server 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.


Multimedia Communications• High-Density File Transfers

• Graphics File Transfers

• Audio File Transfers

• Video File Transfers

• Audio Communication

• Computer-Based Telephony

• Computer-Based Audio Conferencing

• Streaming Audio

• Video Communication

• Video Conferencing

• Streaming Video


Multimedia Communications Student: Blidaru Catalina Elena.

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