Published papers

This paper proposes a Hadoop system that considers both slave server’s processing capacity and network delay for wide area networks to reduce the job processing time. The task allocation scheme in the proposed Hadoop system divides each individual job into multiple tasks using suitable splitting ratios and then allocates the tasks to different slaves according to the computational capability of each server and the availability of network resources. We incorporate software-defined networking to the proposed Hadoop system to manage path computation elements and network resources. The performance of proposed Hadoop system is experimentally evaluated with fourteen machines located in the different parts of the globe using a scale-out approach. A scale-out experiment using the proposed and conventional Hadoop systems is conducted by executing both single job and multiple jobs. The practical testbed and simulation results indicate that the proposed Hadoop system is effective compared to the conventional Hadoop system in terms of processing time.

Beyond 5Gの要求条件7項目と、それに必須な技術を、例を含めて述べた。2030年に始まるbeyond 5Gは、デジタルツイン技術をリアルとサイバーを高度に同期させる技術である。

This paper proposes a priority-aware guaranteed hardware resource allocation in virtual packet optical nodes (VPONs) and describes experimental evidence of service provisioning with the proposed method on testbed. A network based on the VPON brings solution of service diversification and traffic explosion because it provides multiple services by hardware level separated virtual networks such as IP/Ethernet/ Multi-Protocol Label Switching. The VPON has reconfigurable hardware which is dedicatedly allocated for each service and service-specific logical functions are implemented respectively. However, a previous hardware resource allocation method is not efficient. In previous work, the hardware resources once allocated to a service are not reallocated until the service terminated whenever the hardware is not optimally used. In recent years, hardware reconfiguration time has become shorter and it has enabled to apply for service demand change by releasing hardware from services with low demand and reallocating it to other services with high demand. Thus, this paper proposes preemptive dynamic hardware resource reallocation algorithm for VPON and a priority-aware guaranteed hardware resource reallocation method to realize efficient resource usage and high service capacity. Results of the computer simulation show improving service capability. Furthermore, to demonstrate the feasibility of service provisioning with the proposed method, emulators of the virtual packet optical node were constructed and performed resource reallocation. Results of the experiment show that the virtual packet optical node can configure function chains for providing services based on calculation results of the proposed resource reallocation method.

We have proposed a new data-center network architecture 'HOLST' with dynamic and adaptive network configuration for reducing power consumption. This demonstration shows the method of detecting and assigning flows from traffic and application trigger.

AMec (Access-Metro edge computing) is a technology that can reduce the number of edge servers by utilizing in-network excess computing resources such as unallocated cores of control CPU of network devices as a node of the AMec cluster. The important issue is service interruption in that computing resources become unavailable due to executing their main job (e.g. device control and management jobs). In this paper, to avoid interruptions, two types of pod allocation algorithms (both static and dynamic thresholds) are evaluated. The dynamic threshold method is effective in keeping a high allocation success rate even for time-varying numbers of application occurrences.

We demonstrated the effectiveness of a portable emergency optical system in disaster recovery. The system replaces functional units of damaged optical network and recovers a controlplane network by taking the advantage of surviving wireless access.

The continuously growing online shopping is increasing the number of attended home deliveries. The last-mile delivery plays an important role in online shopping satisfaction and especially for food deliveries. This paper focuses on food delivery retailers and particularly investigates the possibility to enhance deliveries using information and data knowledge. In fact, in addition to optimize and to share delivery routes, delivery vehicles could be monitored in order to always maintain shortest delivery delays. We propose in this paper a delivery management architecture targeting these principles. This system is composed of several core mechanisms that should keep delivery delays to a minimum while maintaining low service times. A proof-of-concept of this delivery management system has been developed using Electric Scooters, smartphones and several algorithms. It demonstrates how this architecture could work in a food delivery scenario.