aims’99 workshop heidelberg, 11-12 may 1999 management of qos using mpeg4 dmif standard amaro...

AIMS’99 Workshop

Heidelberg, 11-12 May 1999

Management of QoS using MPEG4 DMIF standard

Amaro Sousa, Institute of Telecommunications, PT

Guido Franceschini, CSELT, IT

AIMS’99 Workshop


Outline

• Describe the problem that is underneath this work

• Introduce DMIF as a possible solution for QoS management of multimedia communications

• Highlight the main issues that should be considered in QoS management

• Report on how DMIF is being assessed as an effective mean to manage QoS in multimedia communications

AIMS’99 Workshop


Some facts!

• Truly networked multimedia services are not yet commercially available

• One of the reasons is because it is difficult to combine the know-how of multimedia technologies and network technologies in the same experts

AIMS’99 Workshop


In the multimedia technologies side:

• At the beginning, multimedia application developers were used to develop applications for stand-alone hardware platforms

• With the advent of World Wide Web, they started to develop applications for “best effort” IP networks

• Their main QoS concern is to use video and audio coding schemes at the lowest bit rates possible

AIMS’99 Workshop


In the network technologies side:

• There are a significant number of network technologies that can support QoS

• Each network technology has its own set of parameters for QoS definition and its own way of supporting QoS communications

• There is no clear view on what are the technologies that will be selected for provision of multimedia services in the future

AIMS’99 Workshop


What is the problem?

• Multimedia application developers don’t want to develop multimedia services to any particular network technology

• Why?

• They have to learn how to deal with QoS in that network technology

• They don’t know if this investment will have return in the future

AIMS’99 Workshop


One possible solution is DMIF

• Delivery Multimedia Integration Framework (DMIF) is Part 6 of MPEG-4 standard

• DMIF defines a Delivery Layer for MPEG-4 multimedia applications

• DMIF defines a DMIF Application Interface (DAI) to be used by the applications

• It is being standardized in a way that can be used by non MPEG-4 applications

AIMS’99 Workshop


The main goals of DMIF

• To hide the delivery technology details to the application

– Local storage– Broadcast sources– Remote application

• To ensure interoperability in the control plane between end-systems

AIMS’99 Workshop


RemoteApp

DAI

DMIF communication architecture (1)

Local

App

DAI

Broadcastsource

LocalStorage

Network

AIMS’99 Workshop


Sigmap

Remote DMIF(Real)

RemoteApp

DNI DAI

Local

App

DAI

DM

IF F

ilte

r

Local DMIFfor Remote

srv

DNI

Sigmap Network

Local DMIFfor Broadcast

Remote DMIF(emulated)

Remote App.(emulated)

Broadcastsource

Local DMIFfor Local Files

Remote DMIF (emulated)

Remote App.(emulated)

LocalStorage

DMIF communication architecture (2)

AIMS’99 Workshop


QoS in DMIF

• A typical multimedia session encompasses the transmission of different media streams in different time instants

• Whenever, a bundle of media streams is to be transmitted between peer applications, the local application requests to local DMIF instance appropriate channels to their transmission

AIMS’99 Workshop


QoS in DMIF (2)

• In the channels request, the application specifies the QoS needed for each media stream (using DAI level QoS metrics)

• One function of DMIF instance is to map the QoS metrics defined at the DAI into the specific QoS metrics of the underneath network technology

AIMS’99 Workshop


MPEG-4 FlexMux tool

Header Insertion

Packetizer

FIFO Queue

Network connection

DAI

DNI

AIMS’99 Workshop


Potential benefits of FlexMux

• Minimise network connections

• Minimise network resources utilisation through statistical multiplexing of different media streams

• Minimise network protocol overhead

AIMS’99 Workshop


Managing QoS through DMIF

• Whenever the applications request connections for a bundle of media streams:

• First, DMIF should decide, based on each individual QoS, which streams should be joined in the same FlexMux and which streams should be sent in separate FlexMux instances

• Then, DMIF should establish an appropriate network connection for each created FlexMux

AIMS’99 Workshop


QoS management - main issues:

• Simplicity

• Network resources optimisation

• Minimisation of network protocol overhead

• Minimisation of average number of connections

• Minimisation of impact on overall delivery performance

AIMS’99 Workshop


QoS Management - a trade-off solution

• Grouping different elementary streams in a single FlexMux can lead to:

– minimisation of network connections but– network resources waste if the different elementary

streams finish in different time instants

• Minimising network protocol overhead can lead to the introduction of higher delay variations

• Different network technologies have different trade-offs

AIMS’99 Workshop


Current work in JUPITER II aims to:

• Investigate how DMIF can effectively support multimedia communications

• This objective is being pursued through the development of DMIF instances for both IP networks with RSVP and “native ATM” networks

AIMS’99 Workshop


IP/RSVP DMIF implementation

• Usage of controlled load service over UDP sockets to provide QoS to media streams

– Overbooking strategy to achieve efficient mapping of DAI level QOS into network level QOS

• Usage of best effort service over TCP sockets to provide reliability

AIMS’99 Workshop


Native ATM DMIF implementation

• Usage of DBR connections for QoS provision to media streams

– Sustainable cell rate strategy to achieve the best trade-off between network resource utilisation and packet delay variation

• Usage of UBR connections for media streams with no QoS requirements

AIMS’99 Workshop


By the end of JUPITER II project:

• We should be able to:

• Propose a common set of DAI level QoS parameters useful for an efficient map into network QoS parameters of the studied technologies

• Propose appropriate strategies for FlexMux management for the two studied network technologies

aims’99 workshop heidelberg, 11-12 may 1999 management of qos using mpeg4 dmif standard amaro...

Documents

multimedia applications

aims99 workshop heidelberg

broadcast remote dmif

standard dmif

local files remote dmif

main goals of dmif

dmif application interface

management of qos