Objective
The project objectives identified in the MoU were as follows :
to co-ordinate and advance European research in the field of methods for the performance evaluation and design of primarily terrestrial based broadband multiservice networks ;
to identify the specific performance and network design problems brought by propositions for broadband multiservice networks ;
to provide solutions to these problems in the form of mathematical models, computer tools or optimisation algorithms together with quantitative evaluations wherever appropriate ;
to influence the design of multiservice switching systems and network architectures by determining optimal traffic control and resource procedures and by evaluating alternative solutions ;
to provide a basis for further integration of European research activities in the field of telecommunications
Activities completed
The nature of the Action objectives and working methods did not lend themselves to the definition of specific activities. Participants contributed reports on in-progress or completed research on subjects within the Action scope. Some 250 COST 242 Temporary Documents (TD) have been listed, the vast majority being research reports. The Final Report of the Action assembles many of the results described in the TDs in a co-ordinated form.
Main results
The Action constituted a sort of running seminar where participants were able to progress together in their understanding of the issues involved, gaining appreciably from interactions with colleagues. The main result is therefore that participants are in a better position to perform relevant research in the field of multiservice network performance evaluation and design.
Research results obtained on individual topics are being used variously :
by ETSI NA5 and ITU-T SG 13 to elaborate standards for broadband network traffic control,
by ITU-T SG 2 to elaborate standards on B-ISDN traffic engineering,
by network operators to define traffic engineering procedures,
by manufacturers to design switch mechanisms and control algorithms,
by teletraffic researchers in universities and industry to establish the mathematical relation between traffic volume, network capacity and quality of service for the class of broadband services.
The work reported in the TDs has been collated in two interim reports published in 1994 and in the Final Report of some 600 pages.
Contacts and co-ordination
Loose ties with RACE II projects (notably, BAF, EXPLOIT and COMBINE) were maintained essentially through the joint participation in COST and RACE by some MC members and experts. Deliverables from COMBINE on connectionless networking, in particular, were made available to members of COST 242. The Action was presented at the workshop entitled "ATM Hot Topics on Traffic and Performance : from RACE to ACTS" organised by the BRAVE project (for the RACE Traffic Management Special Interest Group) in Milan in June 1995. Most proposals for ACTS projects in the field of the Action were not accepted. An exception is EXPERT, a follow-on to EXPLOIT in which a number of the COST 242 group is involved.
Members of COST 242 also have close ties with ITU-T Study Groups 2 and 13 dealing with the standardisation of B-ISDN. Information is exchanged MC meetings on relevant work in ETSI, Eurescom and the ATM Forum.
Current status
The Action has now terminated. Co-operation in this field is, however, continuing in new Action COST 257.
Scope
Activities undertaken within COST Action 242 were concerned with investigating the relationship between traffic characteristics, network capacity and realised quality of service in multiservice networks. Understanding this relationship is essential to multiservice network design, allowing the definition of traffic controls adapted to different service classes and the cost-effective dimensioning of network resources.
The range of topics considered by the project included the following :
Traffic characterisation (self-similarity of LAN traffic, characteristics of video codec output, definition of traffic descriptors) ;
Study of cell delay variation (impact on traffic control, modelling and performance evaluation) ;
Connection admission control methods (worst-case traffic, equivalent bandwidth, adaptive control, neural network approach) ;
Queue scheduling for service integration (priorities, Weighted Fair Queuing)
Access network design (LAN performance, GFC, MAC protocols) ;
Core network design (GoS formulation, traffic clustering, use of VPC, call level access controls) ;
ATM multiplexer performance (Benes methods, accounting for self-similarity, impact of shaping) ;
Multi-rate traffic models (blocking probabilities on links and in networks, trunk reservation).
Method of working
Working methods were based on the Management Committee meetings held at roughly four monthly intervals. The majority of meeting time was devoted to the presentation and discussion of research performed by participants. These meetings naturally gave rise to collaboration between signatories and the constitution of informal ad hoc working groups. It did not prove useful to form formal working groups with separate meetings, since the entire scope was of more or less interest to all participants. The number of participants at the Management Committee meetings grew through the life of the Action from 20 to more than 40. Up to 20 research reports were presented during each MC meeting.
Work planned
A new Action COST 257 with an MoU drafted by members of the Management Committee held its inaugural meeting in Brussels on 30 November 1996. The title of this Action is : "Impact of new services on the architecture and performance of broadband networks".
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
Data not availableCoordinator
92794 Issy Moulineaux
France