Networking in Open Distributed Environments - NODES
The NODES group was established in 1995 to coordinate the research in distributed systems and data communications, and to make it more effective. The group studies how systems are built out of autonomous parts and the interaction and behaviour of these parts. The functionality of the parts and the communication between them, as well as system management, performance and correctness are the main interests of the research group. At the moment, focal points in the research are context sensitivity, mobile always-on connectivity, interoperability and security-trust-privacy. The conditions and implementation of these functions are studied with the help of operating systems, Internet protocols and middleware. The research into tools and methods focuses on performance analysis, formal methods and programming models.
The research in NODES is divided into three sub-areas: wireless internet, collaborative and interoperable computing and computing architectures and platforms. In the area of wireless Internet the focus of research lies on always-on and safe connectivity, spontaneous networks and support for mobility in middleware. In open and distributed systems, the cooperation between enterprises supported by middleware and trust-management are the focal points of research. For computing architectures and platforms the development of the Linux OS and the consideration of resource-restrictions in operating systems are the main research objects.
The research projects in the wireless-internet group were especially interested in IP protocol quality of service and in internet session protocols. The IIP Mixture and IIP Cross projects focused on the challenges of heterogenic communications. The SESSI project developed a version of the internet's SIP protocol that is applicable to spontaneous networks. The HIIT/ARU Fuego Core 2005/7 and DYNAMOS projects studied middleware that supports mobility. The NODES group cooperated with European partners through the European Science Foundation project MiNEMA. The TEKES cooperation agreement was utilised for the cooperation with UC Berkeley (International Computer Science Institute, ICSI). The six-month visit of Professor Tatsuo Nakajima opened up a new cooperation with Waseda University .
The open and distributed systems group developed middleware services that support the cooperation and networking between companies. Partners in the co-operation are application components, which have been developed independently and which are under separate autonomous authorities, which means that the system must have facilities for publishing services, for automatic negotiations about agreements, and for internal management to fulfil the agreements. Middleware services must conceptually be capable of working in parallel on several application platforms. The research is both conceptual, through architectural results, and experimental, through the experimental middleware environment that has been developed. Of the projects, web-Pilarcos has focused on developing general architectures and middleware, while TuBE has developed tools for the trust concepts and trust decisions needed by the architectures. The group has participated actively inEuropean cooperation through the EU's expert network InterOp.
In the field of computing architectures and platforms, research has been concentrated on the Linux OS. The LiSAD project studied how Linux would suit an environment that requires good availability in real time. The LiSED project developed service components for the Linux OS.
Contact person: Professor Kimmo Raatikainen
Homepage: http://www.cs.helsinki.fi/research/nodes/
Publications
T. Karvi, M. Tienari & R. Kaivola: Stepwise Development of Process-Algebraic Specifications in Decorated Trace Semantics. Formal Methods in System Design, Vol. 26, Number 3, pp. 293-317, May 2005.
S. Leggio, J. Manner & K. Raatikainen: Achieving Seamless Mobility in IP-based Radio Access Networks. IEEE Wireless Communications Magazine, Vol. 12 (1), February, 2005.
J. Manner, X. Fu: Analysis of Existing Quality-of-Service Signaling Protocols. RFC 4094, Internet Society, May 2005.
K. Raatikainen (ed.): The First Ten Years of the NODES Group. Helsingin yliopisto, Tietojenkäsittelytieteen laitos, Raportti B-2005-1.
P. Sarolahti & M. Kojo: Forward RTO-Recovery (F-RTO): An Algorithm for Detecting Spurious Retransmission Timeouts with TCP and the Stream Control Transmission Protocol (SCTP). RFC 4138, Internet Society, August 2005.
Research projects
- IIP Cross
- IIP Mixture
- Interop
- LiSAD
- LiSED
- MiNEMA
- Sessi
- TuBE
- web-Pilarcos
International visits
Professor Tatsuo Nakajima, Waseda University , Tokyo , Japan , 9 April – 1 October 2005.