Prospects of photonic switching technologies are described from the viewpoint of an experienced switching system engineer. Photonic switching technologies are classified into five categories, and each of them has the explanation about basic device operation principles with the experimental switching system technologies. The author's view of present technologies is explained with comparison table about these five typical system technologies. Finally, the expectation to the photonic switching system is described that it will be introduced at the beginning of 21st century.

Networking Architecture is the principal engineering concept which defines the design framework of large-scale area-wide telecommunication network. Both IN (Intelligent Network) and TMN (Telecommunication Management Network) are its important subjects. Networking Architecture discussion has a lot of aspects, and it needs time to get final design framework which satisfy telecommunication network requirements over entire 21st century. In this paper, three views of Networking Architecture are introduced, i.e., Historical View, Japanese View and Personal View. Intentionally original (Bell Core) view is excluded because it is popular all over the world.

Handovers are occasionally required for LEO (Low Earth Orbit) satellite systems, since the satellites are always moving. Handovers, however, generally cause some degradation of communication quality. Some LEO systems have a feature of two types of satellites in terms of the direction of their orbits and the handover between satellites of different types may lead to a large change in the path between the service satellites used for the communication. Thus, the degradation can be generally large especially in the case of handovers between different type satellites. As such, best handover plan should be derived so that the number of handovers should be made smallest to minimize the degradation of the communication quality. In this paper, such optimization problems are formulated in relation to the handovers and their solutions are proposed to actualize the optimization of handover plans for LEO satellite systems with two types of satellites.