Hiroaki Harai

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We study routing methods in all–optical switching networks. In all–optical switching networks, the connection with more hops encounters more call blocking, and it is especially true in optical networks with no wavelength conversions. We therefore consider an alternate routing method with limited trunk reservation in which connections with more hops are(More)
We develop a method of high-speed buffer management for output-buffered photonic packet switches. The use of optical fiber delay lines is a promising solution to constructing optical buffers. The buffer manager determines packet delays in the fiber delay line buffer before the packets arrive at the buffer. We propose a buffer management method based on a(More)
In this paper, we describe an autonomous distributed control system that we have been developing for an optical packet and circuit integrated network, and we experimentally evaluate its performance. Colored (i.e., multi-wavelength) optical packet-switched links transfer both control signals for circuit switching (e.g., signaling and routing) and best-effort(More)
This document presents the conceptual design of a new generation network architecture. It is based on the discussions at 14 meetings and 2 seminars, which were held during an 11-month period beginning in May 2006 and attended primarily by the Network The future holds a computing environment characterized by embedded and pervasive computing and networking(More)
In the Internet of Things (IoT) a large number of devices enable data communication and interaction between physical objects and the cyber world. An important feature of IoT is the possibility of having mobile objects equipped with sensing devices. In service-enabled IoT platforms, where data and interacting are provisioned as services, access and(More)
  • Hiroaki Harai
  • 2013 17th International Conference on Optical…
  • 2013
An optical packet and circuit integrated (OPCI) network provides both high-speed, inexpensive services and deterministic-delay, low-data-loss services according to the users' usage scenarios, from the viewpoint of end users. From the viewpoint of network service providers, this network provides large switching capacity with low energy consumption, high(More)
We developed, for the first time to our knowledge, a 640-Gbit/s/port optical packet switch prototype consisting of multiple optical label processors, polarization-independent plomb lanthanum zirconate titanate waveguide optical switches, optical fiber-delay-line buffers, and a parallel pipeline buffer manager. We achieved the error-free switching and(More)
Previous works have shown that wavelength conversion can considerably improve the performance in all–optical networks. However, it is an unrealistic assumption under the current technology and wavelength conversion with a limited range, not a full range, is more promising. In this paper, we propose a new analytic approach for such networks by virtue of the(More)
BACKGROUND There have been only a limited number of cross-cultural studies of social anxiety disorder (SAD), especially as diagnosed with modern operationalized diagnostic criteria and as measured with recently developed assessment instruments. We examined the symptomatological structure and clinical subtypes of patients with DSM-IV SAD among the Japanese(More)
It is true that in all-optical networks, network performance can be improved by wavelength conversion. However, the switching node with wavelength conversion capability is still costly, and the number of such nodes should be limited in the network. In this paper, a performance optimization problem is treated in all-optical networks. We propose a heuristic(More)