Yasutaka Nishimura

Deployment adviser tool for wireless sensor networks

This paper presents a system for the purpose of field deployment of nodes in wireless sensor networks. We propose a mobile phone based deployment adviser tool which is robust as well as practically implementable. The tool advises a layman deployer to create a optimized wireless sensor network by placing of the nodes according to application requirements. The tool is presented here as logically linked sub-modules. Each sub-modules are described in detail. Also we propose an algorithm which helps in distributing the power consumption among the nodes in the network, thus, increasing the network lifetime. The adviser tool has been verified by implementing it in IITH mote. The tool we propose has significant implication since it greatly eases, but more importantly extracts the best performance possible while deploying the wireless sensor networks.

A Device Specification Method Using Doppler Effect of Acoustic Waves

How can you specify a device in the case of file sharing among multiple devices on that spot (e.g., a meeting picture of a social gathering or an alumni association)? One solution is to specify the partner device address (e.g., e-mail address or Bluetooth device address) on your own, but users sometimes feel annoyed or make a mistake with this operation. In this paper, we newly propose a device specification method by user operation of describing a circle in the air, enabling the user to be unaware of the device address. The proposed method uses the Doppler Effect of acoustic waves generated by the operation, enabling to specify multiple partner devices simultaneously and distinguish the device with which you do not want to share, without any pre-planned infrastructure. We measure its performance via an implemented application. The experimental results show that its performance is sufficient for the above use case.

A Device Specification Method by Describing a Circle in the Air

This paper provides a new device specification method, for file sharing among multiple partner devices on that spot (e.g., a meeting picture of a social gathering) and so forth. This is because the past representative solution of inputting or selecting the partner device address (e.g., e-mail address) sometimes irritates users and causes an operation error. The problem to be solved is the development of the method that satisfies the four requirements for the above use case: no need of awareness of the device address by users, simultaneous specification of multiple partner devices, differentiation of a device of a stranger, and no need for pre-planned infrastructure. To solve the problem, our method uses an operation of holding the user device in a hand and describing a circle in the air to surround the partner devices. During this operation, the devices exchange acoustic waves and generate the Doppler Effect. By analysis based on the Doppler Effect, the user can specify only the multiple devices that have been circled. Acoustic waves contribute to the relatively accurate detection of the Doppler Effect, due to their slower propagation velocity than that of electronic waves, e.g., Bluetooth and Wi-Fi. We explain the proposed method in detail, and measure its performance via an implemented application. The experimental results show that it enables the simultaneous specification of multiple devices located in the range within 10 degrees from the direction of the user operation, while distinguishing a device of a stranger located in the range larger than 45 degrees. In the above use case, after putting partner devices on a table, the proposed method of this performance satisfies the four requirements, even if a device of a stranger is located at the next table. Thus, this paper concludes that the proposed method is practical for the above use case.

An Account Provision and Management Architecture for Messaging Services in Emergency

In this paper, we propose a novel architecture for account provision and management in an emergency such as a massive earthquake. This architecture stably and constantly provides messaging services such as web mail to people (users) who want to confirm each others safety in a stricken area. Even if the mobile phone line and fixed line are unavailable in an emergency, the proposed architecture allows users to stably use the services using their device such as a smartphone as usual by providing an emergency account from the server in the evacuation area to all users and binding the emergency account with their own account. Moreover, even if users move to other evacuation areas for seeking their relatives who have become separated from them, this architecture allows users to constantly use services by updating the binding information of the account. We deployed a prototype system based on this architecture to show its effectiveness. Experimental results using this prototype system show that the proposed architecture can provide an emergency account and services to 1,000 users (capacity of the area) simultaneously.

Poster: Node placement adviser for sensor network deployment

In this poster, we propose a new tool, i.e. a node placement adviser, which supports deployment workers of sensor networks. The adviser tool is realized in the form of mobile terminal software and acts as a proxy of an additional node, as well as communicating with those already placed. Based on the communication results, it indicates how favorable the current location is to a worker.

A proposal on ad-hoc pairing of a mobile device and a public device

For the purpose of cooperation between a users mobile device and a public device, we propose ad-hoc pairing, which dynamically generates a pair of a mobile device and a public device. The proposed method has the feature to generate the pair required by a user steadily with few errors and few retries. We measure the period required for pairing procedure via the implemented system to evaluate the efficiency of the proposed method.

Communication Algorithm for Statistic Monitoring in People-Centric Sensing Networks

Mobile phones have great potential to act as global mobile sensing devices due to already being equipped with sensors, e.g., sound, image and acceleration sensors. People as individuals or special interest groups can apply the new sensing devices to form sensing networks called people-centric sensing networks that sense what we are doing and support our daily activities. Most of the sensing applications depend on the ability to monitor statistics including max, average, ranking, rather than raw sensor readings. Such an integration of sensing-capable mobile phones into the networking infrastructure shifts the network’s main utility from data communication to information filtering. Thus, data reduction is one of the major networking challenges for people-centric sensing networks. In this paper, we propose a communication algorithm for statistic monitoring in people-centric sensing networks. The main feature of the proposed algorithm is the ability to reduce communication traffic by eliminating redundant sensing data transmission without increasing the error of the statistics during monitoring. We show how the proposed algorithm is applied to a ranking monitoring application. We also include a simulation study demonstrating the advantages of the proposed algorithm. Furthermore, we show a prototype system where the proposed algorithm is implemented into a mobile phone.

Characterization of Geographic Distribution of Sensor Data by Opportunistic Network

In addition to blog and schedule sharing, sharing physical data, such as noise or temperature values, and event data, such as information recorded when purchasing at a shop, with other nodes located in a distributed manner enables new applications using geographic distribution. Geographic distribution of physical data of noise allows a user to see geographic trends, such as the location of quiet areas, and geographic distribution of event data of shop purchases allows a user to estimate the route for the shop. However, due to the immature ubiquity of dedicated sensor nodes used to detect physical and event data, it is not easy for a user to share physical and event data. In this paper, we propose a new characterization method to provide geographic distribution of physical and event data, by using a mobile phone as a sensor node, since mobile phones have gained wide acceptance. In this method, a mobile phone can share physical and event data with other mobile phones by using opportunistic networks, which may be composed of other mobile phones incidentally located within the transmission range of short distance wireless communication. Furthermore, we define new indicators to take the freshness of physical and event data into account, so that a user can grasp geographic trends in real time. We conducted a computer simulation to show how valuable geographic distribution can be characterized by the proposed method.