The home network of the near future will be a heterogeneous broadband network supporting the use of wired as well as wireless transmission technologies. The variety of services will range from HDTV via gaming to emergency services in the telemedicine area. In this paper, we introduce a technology-independent protocol layer called Inter-MAC which provides a common infrastructure to all home networking devices. The Inter-MAC can establish a connection via different transmission technologies while ensuring appropriate QoS. Key to this is the capability to correctly interpret technology-dependent PHY and MAC parameters for determining QoS when selecting initial and alternative paths, as well as the feature of admission control. Our simulations indicate clearly that the Inter-MAC approach can cope with varying loads, for instance, the time the jitter needed to stabilize was as short as 4 s. The reduced QoS was not noticeable by the user since the jitter introduced by handling additional HDTV flows was less than 0.2 ms for the existing and less than 0.7 ms for the new flow.

The Reference Point Method has been developed by T-Systems as an overall approach for making the complexity in developing ICT convergence solutions manageable. It is based heavily on requirements engineering at the level of business process architecture, technology neutral architecture, technology specific architecture, and telecom architecture. The integration of all these architecture levels is realized by special interfaces at each level called reference points. This method touches the areas of software architecture design and requirements engineering and emphasizes the integration of both. First, it is used to investigate the needed business processes and to get a first insight into the needed system landscape. Then, the corresponding results provide the basis for the operative planning of the ICT systems.

A major challenge in developing and coordinating distributed agents is to accommodate changes introduced at one agent and to propagate it to every other interested party. This presents a special difficulty if the information maintained in a node is highly structured. Examples of such problems are dynamic accommodation of structural changes in distributed software systems or consistency management of multiple viewpoints in typical multiple perspectives/stakeholders settings: modifications or changes not envisaged at "design time" have to be handled at run time without disturbing those parts of the system unaffected by the change. The key feature realizing such dynamic modifications and extensions is a clean separation between internal operations or actions of an individual node or agent and their structural coordination. Thus, general change rules for creation/deletion and connection/disconnection of nodes/agents can be formulated. We consider as an important problem area, dynamic change management of distributed systems. We propose to use distributed graph transformation as the underlying formalism to realize both the specification of evolving distributed systems as well as dynamic change management, thus taking a step towards building configurable distributed systems. The results obtained can easily be transferred to the field of consistency management.

Software development is a staged and evolutionary process. Multiple stakeholders with different needs and views collaborate to build a system from interoperating and heterogeneous development artifacts. In such a setting, one has to cope with requirements changing dynamically during the entire lifetime of the system. Within this changing world living with inconsistencies is natural. Tool support is needed to tolerate inconsistencies and help developers to use them to drive the development process forward. In this contribution we consider the application of distributed graph transformation to the problem of formalizing the integration of multiple perspectives in software development called ViewPoints. Our work concentrates on requirements engineering. We demonstrate how inconsistency management can be used as a tool for requirements analysis by presenting a sample integration of architecture design and performance evaluation views.

We consider the problem of detecting and handling inconsistencies in software development processes using a graph based approach. It seems to be a natural way to express the various options and possibilities in attacking the problem. We apply the techniques developed in the area of software architecture design which uses in a structured way performance models in order to produce a design which incorporates also nonfunctional requirements in terms of quantitative performance.