Hiroaki Nose

Development of a High-Speed Simulator for Sensor Network Protocols Using GPGPU

In this research, we propose a high-speed simulator for rapidly determining protocol performance of a sensor network comprised of many terminals. We have developed this simulator by using GPGPU technology, in which widely used GPUs (Graphics Processing Units) are applied to general-purpose computing. This simulator executes at high-speed by using the parallelism that is a structural feature of GPUs, and enables simultaneous execution of simulations with various values of the parameters in the protocol. The result is high-speed simulations using inexpensive hardware which previously could only be processed using a supercomputer.

Construction of a Sensor Network to Forecast Landslide Disasters Sensor Terminal Development and On-Site Experiments

We believe it is extremely important to quickly communicate information — on matters such as the extent of the damage and the safety of affected persons — when a large-scale earthquake or other disaster occurs. However, if electric power is lost, communication will be impossible with existing information networks. For this reason, we have built an Ad-Hoc network in Shiojiri City enabling communication even if electric power is lost due to a large-scale disaster. Using this Ad-Hoc network, we are building a sensor network to forecast landslide disasters. Among the various sensors installed to the sensor terminals, this paper reports in particular on observation results with EC sensors.

Construction and evaluation of a regional protection system employing power-saving wireless terminals without using GPS modules

In recent years, there have been many cases of violent crimes against children. As a result there is an increasing need for systems which can identify the current positions of children, and keep watch over them in time slots where they may be alone, such as on the way to and from school. At present, the most typical approach is to have the children carry a wireless terminal so they can be tracked, but the power-saving performance of such devices needs to be improved. As a result, we have proposed a method of estimating the position of children without using GPS, and thereby improved the power-saving performance of the wireless terminals. In addition, we have confirmed through measurement experiments in an experiment field that the position of children can be appropriately estimated using this technique.

Development and Evaluation of a High-Speed Simulator for Wireless Sensor Network Protocols using GPGPU

In this research, we propose a high-speed simulator for rapidly determining protocol performance of a sensor network comprised of many terminals. We have developed this simulator by using General-Purpose Computing on Graphics Processing Units (GPGPU) technology, in which widely used Graphics Processing Units (GPUs) are applied to general-purpose computing. This simulator executes at high-speed by using the parallelism that is a structural feature of GPUs, and enables simultaneous execution of simulations with various values of the parameters in the protocol. In order to determine the effectiveness of the proposed method, a simulator for a sensor network, in which communication follows a simple protocol with carrier sensing, was realized with a system using GPGPU. As a result, it was confirmed that a high speed 4.6 times faster than the case using an ordinary CPU can be achieved when the number of terminals is 1024. It was also confirmed that 100 simulations can be carried out at a speed about 60 times faster than the case where a single simulation is repeated using a CPU in which parameters are changed in a batch fashion.

Construction and evaluation of a regional protection system employing power-saving wireless terminals without using GPS modules.

In recent years, there have been many cases of violent crimes against children. As a result there is an increasing need for systems which can identify the current positions of children, and keep watch over them in time slots where they may be alone, such as on the way to and from school. At present, the most typical approach is to have the children carry a wireless terminal so they can be tracked, but the power-saving performance of such devices needs to be improved. As a result, we have proposed a method of estimating the position of children without using GPS, and thereby improved the power-saving performance of the wireless terminals. In addition, we have confirmed through measurement experiments in an experiment field that the position of children can be appropriately estimated using this technique.

Proposal and evaluation for wireless sensor network which use terminal that eliminated receiver circuit

Sensor network terminals are installed in large numbers in the field and transmit data periodically by radio. Such terminals must be miniaturized, and save power so that each device can operate by battery for several years. As one way to satisfy these two conditions, in this research we propose a terminal design which eliminates the receiver circuit. Because there is no receiver circuit, circuitry can be miniaturized, and power can be saved because there is no need to consume power to receive signals. However, the terminals cannot perform carrier detection and reception acknowledgement because there is no receiver circuit. We propose following two new protocols to solve this problem.

Terminal Design without Using Receiver Circuits for Wireless Sensor Networks

Sensor network terminals are installed in large numbers in the field and transmit data periodically by radio. Such terminals must be miniaturized, and save power so that each device can operate by battery for several years. As one way to satisfy these two conditions, in this research we propose a terminal design which eliminates the receiver circuit. Because there is no receiver circuit, circuitry can be miniaturized, and power can be saved because there is no need to consume power to receive signals. However, the terminals cannot perform carrier detection and reception acknowledgement because there is no receiver circuit. We propose following two new protocols to solve this problem.