Showing papers by "Koichi Asatani published in 2012"

A new application level link aggregation and its implementation on Android terminals

Abstract: Link aggregation bundles multiple physical links on a single virtual link, enabling very high-speed and large-capacity data communications. It also enables redundant communications. Several link aggregation methods have been proposed. These methods utilize transport layer link aggregation. In this paper, a new application level link aggregation is proposed and implemented on Android OS, which is one of the popular OSs for mobile devices such as smartphones and tablet PCs. The proposed application level link aggregation method is verified with use of an implemented terminal.

Proposed presence system for safety confirmation

Abstract: The registration process stores presence information in the presence server, which includes ID for authorization, registered date and time, and location. The reference process loads the presence information using the ID as a search key. Safety confirmation service registers a user's presence and refers to his/her friend's presence. However, existing systems require separate operations for registration and reference. Users need to enter their telephone number as an ID during the registration process and their friend's telephone number as an ID during the reference process. As a result, many steps are required for registration and reference operations. We therefore propose two methods to reduce the number of steps. The presence update method registers the card ID, location of card reader, date, and time by just swiping a contactless smart card through a card reader. The presence migration method from an external Social Networking Service (SNS) selects the place, date, and time in the external SNS using an email address. Both these methods are invoked by swiping the contactless smart card through the card reader, the registration and reference operations of presence information are executed at the same time. Using a prototype system that implemented these methods, we confirmed that the initial values can be obtained from external SNSs and many users can quickly register and refer safety information.

Carrier-Grade Networks toward the Future - NGN and Its Issues -

Abstract: Next Generation Network is designed as the next generation carrier- grade network. Reflecting the ICT trends, NGN adopts packet-based network to flexibly accommodate telephony and data traffics. The IP is adopted as the network layer protocol with additional resource and admission control functionalities enabling QoS management. This paper describes global ICT trends, outline of NGN and its issues toward the future.

Design of the mitigation information network in urban area

Abstract: In Japan, major earthquakes are predicted to occur in the metropolitan area In the time of such a disaster, communication systems will play an important role to transfer mitigation information such as instruction for people to move the evacuate area and for contractors to recover city functions However, mitigation information may be unable to transfer smoothly, because of telecom infrastructure damage and conflicting information Objective of this research is to clarify system requirements in order to build the mitigation network using wireless LAN systems Use cases for network design are created based on reports and actions of public organizations when the great East Japan earthquake was happened We propose the mitigation information network composed of three sub networks; the long-distance wireless LAN for connecting to the backup station in non-disaster area, the midrange wireless LAN for connecting between countermeasures offices, the information gathering and distribution network in disaster area In order to decide specification of wireless systems and position of antenna, we measure throughput of 25GHz and 49GHz band between Shinjuku and Hachioji for the long-distance wireless LAN Also we measure throughput of 49GHz band in Nishi-Shinjuku area, where is forest of tall buildings, for the information gathering and distribution network The mitigation network will be built with these results