The rapid advances in data communication networks have greatly increased the possibilities to make use of the various computational and information services available within reach of a computer network. These services may have different origins, they are implemented on different types of computational platforms, and they can be located on sites far apart. As different services become reachable, interoperability of services must be considered. Distributed computation needs an enhanced functionality of the infrastructure. Especially, emerging technologies around wireless communication open up ways for new flexibility.
The department started research activity in the area of open distributed processing at the end of 1980's. In our first project (AHTO) we designed a distributed software environment (``middleware'') offering for a user a homogeneous interface to the computing services available in a heterogeneous computer network. Since that time the department has participated in the development of the Reference Model for Open Distributed Processing, under the auspices of ISO and ITU-T (former CCITT).
The DRYAD project, started in 1992, studies open distributed systems, such as Open Distributed Processing reference model (ODP-RM). Especially we concentrate on heterogeneous environments that are created by integrating autonomous computing systems. The technology solutions at each system can be heterogeneous at any level: hardware, operating system, middleware, languages, and applications.
Basic problem in such an environment is the interoperability of systems: the objects should be able to communicate with each other reasonably regardless of the differences in peer system technologies. We try to solve the interoperability problem by designing distributed middleware layer mechanisms, that can themselves be heterogeneous. The project considers also open platforms, such as OMG/CORBA, and management aspects of open platforms.
The DRYAD project has developed a prototype software package for some of the middleware services - especially the trading function. The project has been also actively involved with international standardization work on ODP reference model. For example, one of the standardization meetings was held in Helsinki, in May 1995.
The members of the DRYAD project group are Prof. Martti Tienari, M.Sc. Lea Kutvonen, Petri Kutvonen, M.Sc. Liisa Marttinen and Pekka Kähkipuro. The work has been partially funded by the Technology Development Centre TEKES, ICL Personal Systems, Telecom Finland, Helsinki Telephone Company, Finnish State Computing Centre, and Center for Scientific Computing.
Home page: http://www.cs.helsinki.fi/research/dryad/