Yoshinari Kumaki

SDL-Net: a wireless access link to broadband multimedia networks

SDL-Net (Super high speed DownLink Network) is proposed as a wireless access link to a broadband multimedia network, and its basic features are described. In the SDL-Net, the transmission data rate in downlink is 30 to 300 times faster than the transmission data rate in uplink. With this asymmetric architecture, most of multimedia personal communication services are realized through hand-held portable multimedia terminals. The SDL-Net is economically constructed by additionally installing high speed downlink transmitters in existing narrowband personal communication networks. By combining high speed downlink with narrowband links, both seamless CBR services such as voice communication and spot beam VBR services such as electronic publishing are realized.

A 0.8- mu m BiCMOS ATM switch on an 800 Mb/s asynchronous buffered banyan network

An experimental element switch LSI for asynchronous transfer mode (ATM) switching systems was realized using 0.8- mu m BiCMOS technology. The element switch transfers cells asynchronously when used in a buffered banyan network. Three key features of the element switch architecture are CASO buffers to increase the throughput, a synchronization technique called SCDB (synchronization in a clocked dual port buffer) to make possible asynchronous cell transmission on the element switches with simple hardware, and an implementation technique for virtual cut through, called CELL-BYPASS, which lowers the latency. An implementation of elastic store is proposed to achieve high-speed synchronization with simple hardware. The element switch LSI adopts an emitter-coupled-logic (ECL) interface. The maximum operation frequency of the element switch LSI is 200 MHz (typical). >