CORBA-based Middleware Research Articles

Resource conscious development of middleware for control environments: a case of CORBA-based middleware for the CAN bus systems

While it is imperative to exploit middleware technologies in developing software for distributed embedded control systems, it is also necessary to tailor them to meet the stringent resource constraints and performance requirements of embedded control systems. In this paper, we propose a CORBA-based middleware for Controller Area Network (CAN) bus systems. Our design goals are to reduce the memory footprint and remote method invocation overhead of the middleware and make it support group communication that is often needed in embedded control systems. To achieve these, we develop a transport protocol on the CAN and a group communication scheme based on the publisher/subscriber model by realizing subject-based addressing that utilizes the message filtering mechanism of the CAN. We also customize the method invocation and message passing protocol of CORBA so that CORBA method invocations are efficiently serviced on a low-bandwidth network such as the CAN. This customization includes packed data encoding and variable-length integer encoding for compact representation of IDL data types. We have implemented our CORBA-based middleware using GNU ORBit. We report on the memory footprint and method invocation latency of our implementation.

A CORBA-based Middleware for an Adaptive Streaming Server

A CORBA-based infrastructure for an adaptive multimedia server is introduced, enabling dynamic migration or replication of certain multimedia applications among a set of available server nodes. The requirements from both the server's and the middleware's point of view are discussed. A specification of a CORBA interface and a corresponding implementation is presented. Finally, as a proof of concept, measurements of the implementation are shown and discussed. The measurements show the importance of the related servers' distribution on the network.

Network computing

Network computing represents a new computing paradigm in which all information, data and software applications reside on a network and are accessed on demand by users. This approach to computing offers the potential for users to access ‘everything‘ from ‘anywhere‘, removing the constraints of localised storage of information and applications, and, based on evolving standards, allowing access from a range of ‘information appliances‘. This paper introduces the basic ideas behind network computing, and examines a range of forms it could take. It describes the current status of commercial network computing approaches, with particular emphasis on the use of the Java language, and examines the associated benefits and technical issues. A prototype BT system, developed using Java client software and CORBA-based middleware, is described.