Keiji Tsunoda

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.

Network and protocol architectures of hybrid multimedia mobile access communication system

We present a network architecture of the hybrid multimedia mobile access communication (MMAC) system through which a number of broadband multimedia mobile communication services are provided for hand-held, small radio terminals. In the hybrid MMAC system, the conventional personal communication system (PCS) link is used for uplinks while the broadband radio link under development in the MMAC Promotion Council is utilized for downlinks. The hybrid MMAC system has a lot of advantages such as the small terminal size, the low terminal cost and the smooth introduction of the full standard MMAC system, which is a bi-directional broadband system. In this paper, the concept and the network architecture of the hybrid MMAC system are presented. The protocol stacks and the operation sequences of this system are also described.