Eiji Kamagata

Location registration and paging for in-building personal multi-media communication systems

This paper describes a novel mobility management scheme which is efficient for multi-media in-building mobile communication systems. Most in-building mobile communication systems will be realized in a pico-cellular structure. An in-building user mobility model to be used for designing a pico-cellular systems mobility management scheme is first established. Then proposed is a novel location registration and paging scheme which can simultaneously cope with the bursty location registration traffic and the increased paging traffic. In addition, this scheme can cope with the call set up delay requirements in multi-media communication. The performance of the proposed scheme has been evaluated by computer simulation in which the user mobility model at lunch time in an office building is used.

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.

Zero-Watt Networked Standby: Development and Evaluation of a Home A/V Network System

Energy conservation is an important global issue. Home is the third largest energy consumer, and 10% of the home energy is standby power of home appliances. The proliferation of home networks increases the standby power. The conventional technologies for low networked standby power such as WoL require continuous AC power, as much as 0.5 watts, to monitor wake-up signals. The large portion of the consumed power is due to the power loss in an AC-DC converter. Moreover, the technologies are applicable only to the specific network types such as Ethernet and IEEE802.11. We propose a solution to reduce the networked standby power down to zero virtually, regardless of the network type. For monitoring wake-up signals, the solution utilizes the precharged power in an ultra capacitor without using AC power supply almost all the time. In order to realize this idea, the solution also utilizes unique and simple protocol dedicated only to the networked standby /wake-up functionality. This protocolenables the monitoring circuit to consume very small power enough for the capacitor to supply. The networked standby/wake-up functionality is easily combined with any conventional network application protocol by protocol address mapping. As one realization example of our solution, we implemented an experimental system which is integrated with an ultra low power wireless signal receiver and extended UPnP protocol. The system evaluation showed that our solution achieves the zero-watt networked standby while keeping network functionalities. Moreover, the analysis of the results shows that the practical networked standby power is one seventeenth of the conventional technologies in usual usage. This corresponds to 1.11 kg-CO2 emission reduction per year per product.

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.

Zero-watt Networked Standby: Reducing Power Consumption of Home A/V Network Systems

Energy conservation is an important global issue. The home is the third largest energy consumer, and 10% of the home energy use is standby power of home appliances. The proliferation of home networks increases the standby power. The conventional technologies for low networked standby power such as WoL require continuous AC power, as much as 0.5 watts, to monitor wake-up signals. A large portion of the consumed power is due to the power loss in the AC-DC converter. Moreover, the technologies are applicable only to the specific network types such as Ethernet and IEEE802.11. We propose a solution to reduce the networked standby power down to zero virtually, regardless of the network type. For monitoring wake-up signals, the solution utilizes the pre-charged power in an ultra capacitor without using the AC power supply for almost all the time. In order to realize this idea, the solution also utilizes a unique and simple protocol dedicated only to the networked standby/wake-up functionality. This protocol enables the monitoring circuit to consume a very small amount of power, small enough for the capacitor to supply. The networked standby/wake-up functionality is easily combined with any conventional network application protocol by protocol address mapping. As one realization example of our solution, we implemented an experimental home A/V system which is integrated with an ultra low power wireless signal receiver and extended UPnP protocol. The system evaluation showed that our solution achieves the zero-watt networked standby while keeping network functionalities. Moreover, the analysis of the results based on a statistical survey shows that the practical networked standby power is 30 mW when our solution is applied to a TV system, which corresponds to one seventeenth of a conventional technology, WoL. It means that our solution improves power consumption by 22% which corresponds to 1.11 kg-CO2 emission reduction per year per product.