AIMS’99 Workshop Heidelberg, May 1999 Management of QoS using MPEG4 DMIF standard Amaro Sousa, Institute of Telecommunications, PT Guido Franceschini, CSELT, IT

AIMS’99 Workshop Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 Remote App DAI DMIF communication architecture (1) Local App DAI Broadcast source Local Storage Network

AIMS’99 Workshop Heidelberg, May 1999 Sig map Remote DMIF (Real) Remote App DNIDAI Local App DAI DMIF Filter Local DMIF for Remote srv DNI Sig map NetworkLocal DMIF for Broadcast Remote DMIF (emulated) Remote App. (emulated) Broadcast source Local DMIF for Local Files Remote DMIF (emulated) Remote App. (emulated) Local Storage DMIF communication architecture (2)

AIMS’99 Workshop Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 MPEG-4 FlexMux tool

AIMS’99 Workshop Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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 Heidelberg, May 1999 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