Cgmm presentation on distributed multimedia systems

Distributed Multimedia Distributed Multimedia SystemsSystems

MCIT-103MCIT-103

CGMMCGMM

IntroductionIntroduction

A distributed multimedia system combines A distributed multimedia system combines a variety of multimedia information a variety of multimedia information resources over a network into an resources over a network into an application used by the client.application used by the client.

The system is based on the The system is based on the interaction interaction between the user and the application.between the user and the application.

The The user can control when to receive what user can control when to receive what datadata and also control the data flow. and also control the data flow.

IntroductionIntroduction

Most multimedia is inherently Most multimedia is inherently time-basedtime-based – the – the arrival timearrival time and and arrival orderarrival order of data packets is of data packets is important.important.

The distributed environment is The distributed environment is capable of capable of serving a large number of end usersserving a large number of end users to to concurrently access a large number of concurrently access a large number of repositories of stored data.repositories of stored data.

We just don’t want interactive multimedia over We just don’t want interactive multimedia over our networks… we want it to be our networks… we want it to be reliablereliable and of and of high-quality high-quality also.also.

HistoryHistory

60s-70s: Distributed computing research 60s-70s: Distributed computing research with earliest networkswith earliest networks

80s: Compact disc, personal computer 80s: Compact disc, personal computer explosionexplosion

80s-90s: Distributed multimedia system 80s-90s: Distributed multimedia system research (video conferencing, et al)research (video conferencing, et al)

90s: Current prevalent paradigm (quality of 90s: Current prevalent paradigm (quality of service management)service management)

GoalGoal

Simplicity in and of itself: We want and Simplicity in and of itself: We want and need need high quality, reliable, interactive high quality, reliable, interactive multimedia.multimedia.

The general Internet structure is not The general Internet structure is not sufficient to accomplish this,sufficient to accomplish this,

A distributed multimedia system will add A distributed multimedia system will add protocols and architectures on top of the protocols and architectures on top of the Internet (or LAN) to guarantee quality Internet (or LAN) to guarantee quality levels, thereby satisfying our need.levels, thereby satisfying our need.

DefinitionsDefinitions

BandwidthBandwidth: data rate through a : data rate through a component.component.

LatencyLatency: time needed for a packet to travel : time needed for a packet to travel end to end.end to end.

Loss rateLoss rate: acceptable drop-frame ratio.: acceptable drop-frame ratio. Quality of service managementQuality of service management: :

negotiation and allocation of computing negotiation and allocation of computing resources.resources.

DefinitionsDefinitions

Flow specificationFlow specification: explicit representation : explicit representation of required resources.of required resources.

Traffic shapingTraffic shaping: using buffers at source : using buffers at source and destination to smooth data flow.and destination to smooth data flow.

Admission controlAdmission control: allowing or denying : allowing or denying client requests based on available client requests based on available resources.resources.

Distributed multimedia system consists of three different basic components:

• an Information server,• a wide area network, and• a multimedia client on the user side.

Architecture of DMMS

Architecture of DMMSArchitecture of DMMS

Wide area gateway Videoserver

DigitalTV/radioserver

Video cameraand mike

Local network Local network

Controller

Features and StructureFeatures and Structure

Client

Source Source Source

QOS QOS QOS

Main QOS

Transmission Line (Internet)

1: Sources provide flow spec to main QOS manager through local QOS managers

2: Main QOS ready to reserve resources

3: Client send request to main QOS

4: Main QOS decides if client can be served based on available resources

5: If so, main QOS tells local QOS to allocate resources (if not, client is rejected)

6: Service begins

7: Main QOS and local QOS monitor resource usage / quality, adjust allocated resources if necessary

8: Return to step 4 if new client connects

9: Service ends, resources are freed

Need of Multimedia ServerNeed of Multimedia Server

Current personal computers, workstations Current personal computers, workstations and servers are designed to handle and servers are designed to handle traditional forms of data.traditional forms of data.

These systems do not perform well for These systems do not perform well for multimedia data, requiring fast data multimedia data, requiring fast data retrieval and guaranteed real time retrieval and guaranteed real time capabilities.capabilities.

The I/O capacity is usually a severe The I/O capacity is usually a severe bottleneck. bottleneck.

Requirements for Multimedia Requirements for Multimedia ServerServer

Minimal Response timeMinimal Response time: The server : The server must be able to minimize response time must be able to minimize response time to live onto the expectations of the user. to live onto the expectations of the user.

Fast Processing CapabilityFast Processing Capability: To : To guarantee fast response time, clients guarantee fast response time, clients should be processed fast and data should be processed fast and data access rates should be minimized. access rates should be minimized.


Reliability and availabilityReliability and availability:: Like any other server, multimedia server must Like any other server, multimedia server must

be reliable.be reliable. The larger the number of users and volume of The larger the number of users and volume of

data handled by the server, the more difficult data handled by the server, the more difficult is to guarantee reliability.is to guarantee reliability.

To provide fault tolerance special hardware To provide fault tolerance special hardware and software mechanisms must be employed. and software mechanisms must be employed. The time the server is unavailable should be The time the server is unavailable should be minimized. minimized.


Ability to sustain guaranteed number of Ability to sustain guaranteed number of streamsstreams::

Another important factor is the Another important factor is the maximum number of data streams the maximum number of data streams the server can simultaneously handle. server can simultaneously handle.

This affects the total number of clients This affects the total number of clients the server can handle. the server can handle.


Real-time deliveryReal-time delivery:: This needs profound requirements on This needs profound requirements on

the resource scheduling at the the resource scheduling at the operating system level.operating system level.

For this accurate real-time operating For this accurate real-time operating systems have to be developed. systems have to be developed.


High storage capacityHigh storage capacity: The server must : The server must have a large storage capacity to store have a large storage capacity to store MM data and variety of information.MM data and variety of information.

For this, the server may be required to For this, the server may be required to compress and encode video and image compress and encode video and image data prior to transport or storage.data prior to transport or storage.

The performance of compression and The performance of compression and signal processing should be optimized. signal processing should be optimized. This might require special hardware. This might require special hardware.


Quality of ServiceQuality of Service: (Qos) : (Qos) is a set of is a set of parameters describing the tolerable end-to-end parameters describing the tolerable end-to-end delay, throughput, and the level of reliability in delay, throughput, and the level of reliability in multimedia communication and presentation.multimedia communication and presentation.

The server should be able to provide and adapt The server should be able to provide and adapt itself to different QoS requirements, according to itself to different QoS requirements, according to the characteristics of the client's terminal, the the characteristics of the client's terminal, the network connection and the requested data network connection and the requested data type. type.

How To UseHow To Use

A distributed multimedia system is a A distributed multimedia system is a combination of source hardware, QOS combination of source hardware, QOS manager software, and a transmission linemanager software, and a transmission line

Can be bought as a complete, dedicated, Can be bought as a complete, dedicated, proprietary package – very expensive!proprietary package – very expensive!

Can be built using existing hardware and Can be built using existing hardware and Internet / LAN connection lines… all that is Internet / LAN connection lines… all that is needed beyond that is QOS management needed beyond that is QOS management software – can be purchased or developedsoftware – can be purchased or developed

ApplicationsApplications

Video conferencingVideo conferencing Live news feedsLive news feeds Video-on-demandVideo-on-demand Remote-control of exploratory robotsRemote-control of exploratory robots Remote musical collaborationsRemote musical collaborations Remote surgical operationsRemote surgical operations

Significant PointsSignificant Points

Distributed multimedia systems exist to Distributed multimedia systems exist to guarantee quality of deliveryguarantee quality of delivery levels. levels.

Resource Resource reservationreservation is the key. is the key. Additional clients Additional clients do notdo not degrade system – degrade system –

they can be refused if resources are they can be refused if resources are scarce.scarce.

Quality guarantees are of paramount Quality guarantees are of paramount importance, whether used for business, importance, whether used for business, entertainment, scientific or health-related entertainment, scientific or health-related applications.applications.

Current Trends in DMSCurrent Trends in DMS

Currently some of the distributed multimedia Currently some of the distributed multimedia systems are: systems are:

Video on DemandVideo on Demand: The consumer can : The consumer can select a video or any program on demand. select a video or any program on demand. The application consists of Interactive The application consists of Interactive features like forward, rewind and pause.features like forward, rewind and pause.

Interactive shopping and electronic Interactive shopping and electronic commercecommerce: Home shopping will provide a : Home shopping will provide a customisable shopping environment.customisable shopping environment.

News and Reference ServicesNews and Reference Services: News on : News on Demand is similar to VOD but it provides Demand is similar to VOD but it provides sophisticated news retrieval and reference sophisticated news retrieval and reference services that combine live and achieved services that combine live and achieved video, access to textual data and still video, access to textual data and still photography from various sources.photography from various sources.

The information is delivered based on a The information is delivered based on a filtering criteria kept by the user.filtering criteria kept by the user.

Current Trends in DMSCurrent Trends in DMS

SummarySummary

Serving multimedia requires strict resource control to Serving multimedia requires strict resource control to maintain quality.maintain quality.

Resources consist of bandwidth, latency, and loss Resources consist of bandwidth, latency, and loss rate, among othersrate, among others

Source components declare the resources they need Source components declare the resources they need in in flow specifications.flow specifications.

Quality of service managersQuality of service managers negotiate and reserve negotiate and reserve resources to guarantee quality.resources to guarantee quality.

Source + flow spec + QOS manage + transmission Source + flow spec + QOS manage + transmission lines = lines = distributed multimedia systemdistributed multimedia system

ReferencesReferences

Distributed Multimedia Systems – An Overview - Distributed Multimedia Systems – An Overview - Gaurav Jain , Indian Institute of Gaurav Jain , Indian Institute of Information Technology Information Technology

THANK YOU

Cgmm presentation on distributed multimedia systems

Engineering

multimedia client

different qos requirements

main qos manager

main qos ready

data rate

information server

storemm data

volumeof data