Kenichi Ohtsuki

Interaction of Magnetostatic Surface Waves with Drifting Carriers

The dispersion relation of magnetostatic surface waves in a composite structure of a ferrite stab and infinite semiconductor is solved numerically for ω real and k complex. The following properties of the convective amplification of the waves are derived from the analysis: The net amplification is obtained when the carrier drift velocity is larger than the phase velocity of the wave; when the carrier density of the semiconductor is small, the amplification factor increases linearly with the carrier drift velocity; there is an optimum value of the carrier density to obtain the maximum amplification factor; the amplification factor increases with the signal frequency.

A hyper-distributed switching system architecture for B-ISDN

A hyper-distributed switching system architecture is proposed for a large-scale asynchronous transfer mode (ATM) switching system to handle heterogeneous traffic and sophisticated services for B-ISDN. The system consists of a non-intelligent module with small capacity ATM switches allocated separately at a single stage, and many independent modules have call processing. The same architecture from a small-scale system can be used in a large-scale system by connecting the ATM links among the regularly allocated ATM switches. Also proposed are a nonblocking switching configuration, efficient intermodule connection, concentrated quality control, state dependent intermodule routing, and virtual channel assignment to decrease the label conversion table size in the hyper-distributed switching system.<<ETX>>