Activities at SICS's Computer and Network Architecture Laboratory
by Bengt Ahlgren
The focus of the Computer and Network Architecture (CNA) laboratory
is in the networking technology and the computing platform for
advanced distributed applications on the Internet. The networking
technology ranges from the design of hardware for IP routers over
core Internet protocols in the network and transport layers to
how distributed applications use the network service.
The CNA lab participated in the EU Esprit LTR project HIPPARCH
together with researchers from INRIA Sophia-Antipolis, University
College London, Uppsala University, Dassault Electronique (now
part of Thompson-CSF) and University of Technology, Sydney. The
project was finished at the end of August 1998 with excellent
reviews. The project therefore received additional funding for
exploiting the results further.
In HIPPARCH we have been investigating novel architectures for
high performance communication protocols based on the Application
Level Framing (ALF) and Integrated Layer Processing (ILP) concepts.
The project also adopted the notion of “network conscious applications”,
that is, applications that are aware of varying network conditions
and that adapt in one way or another to these conditions in order
to optimize application performance. This notion is based on the
belief that it is only the application itself that can make the
best adaptation decision, for example, change audio encoding algorithm.
The results from the project include a protocol compiler supporting
the development of ALF based applications, control algorithms
for network consciousness, a multicast based reliable distribution
protocol, a QoS model for network conscious applications and a
network bandwidth probing tool.
We are also participating in the EU Esprit project Pegasus II.
The other partners are University of Cambridge, University of
Twente, University of Glasgow and Citrix Ltd (Cambridge, UK, formerly
APM Ltd). The Pegasus II project develops an operating system,
Nemesis, which is a generic platform for multimedia applications
featuring effective user control over resource allocation policy.
A mobile ad-hoc network, or “MANET”, is a self-configuring multihop
wireless packet network, where all nodes participate in forwarding
packets to their destinations. All nodes are also mobile, and
thus free to move arbitrarily. Ad-hoc networking is a hot research
area in the area of mobile communication. The research issues
we are working on in this area are power management, routing protocols
and addressing to provide Internet connectivity to ad-hoc networks.
In a previous project we have developed a dimensioning model for
IP telephony. We are continuing this work with simulations and
measurements in experimental networks to validate the model and
to evaluate if an IP network with differentiated services can
provide the necessary network quality of service for telephony.
For more information on the Computer and Network Architecture
Laboratory, see http://www.sics.se/cna/cna.html
Please contact:
Bengt Ahlgren - SICS
Tel: +46 8 633 1562
E-mail: bengta@sics.se
