著者

Mitsuhiko Shimomura Nicolas Chauvet Mikio Hasegawa Makoto Naruse

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.13, no.1, pp.101-111, 2022 (Released:2022-01-01)

参考文献数

10

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High-bandwidth irregular oscillations caused by optical time-delayed feedback subjected to the laser cavity, known as laser chaos, have been investigated for various engineering applications. Recently, a fast decision-making algorithm for a multi-arm bandit problem by utilizing laser chaos time series has been demonstrated. Furthermore, the arms order recognition of the reward expectation for each arm has been successfully developed by incorporating the notion of the confidence interval regarding the reward estimate. However, in previous studies, the verification was limited to numerical experiments; real-world demonstrations were not conducted. This study experimentally demonstrated that the arm-order recognition algorithm is successfully operated in channel order recognition in wireless communications while revising the original strategy to take into account the wireless application requirements. Such accurate arm rank recognition involving non-best arms would be useful for various real-world applications such as channel bonding, among others.

著者

Daijiro Koyama Yunzhuo Wang Nobuyasu Shiga Satoshi Yasuda Nicolas Chauvet Makoto Naruse

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.12, no.2, pp.225-235, 2021 (Released:2021-04-01)

参考文献数

9

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The growing demand of high-bandwidth and low-latency information transfer in information and communication technologies such as data centers and in-vehicle networks has increased the importance of optical communication networks in recent years. However, complicated arbitration schemes can impose significant overheads in data transfer, which may inhibit the full exploitation of the potential of optical interconnects. Herein, we propose an arbitration protocol based on precision time synchronization via wireless two-way interferometry (Wi-Wi), and numerically validate its efficiency including the ability to impose a strict upper bound on the latency of data transfer. We introduce the notion of arbitration point (AP) for a designated time duration, which is shared by all nodes thanks to the time synchronization by Wi-Wi, to determine data transmission while ensuring avoiding collision. Compared with the conventional carrier sense multiple access/collision detection (CSMA/CD)-based approach, a significant improvement in the data transfer was observed especially in the cases with high traffic flow rate. Furthermore, we conducted a proof-of-principle experiment for Wi-Wi-based data transfer between two electrically connected nodes and confirmed that the skew was less than 300 ns and remained stable over time. Conversely, non-Wi-Wi-based data transfer exhibited huge and unstable skew. These results indicate that precision time synchronization is a promising resource to reduce the communication overheads and ensure low latency for future networks and real-time applications.

著者

Kaori Kuroda Hiroki Kato Song-Ju Kim Makoto Naruse Mikio Hasegawa

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.9, no.1, pp.74-81, 2018 (Released:2018-01-01)

参考文献数

10

被引用文献数

23

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Recently, various mobile communication systems have been widely deployed, and mobile traffic is increasing. However, the bandwidth available for mobile communications is limited, hence the scarcity of radio resources in mobile communications is a serious problem. As an approach to solve this problem, cognitive wireless communication models have been proposed. These model search for vacant time slots in multi-channel wireless communication systems. Although previous studies have shown that frequency utilization efficiency can be improved by multi-armed bandit algorithms, channels are assumed to be independent. However, channels used in 2.4 GHz wireless LANs (such as IEEE802.11b or IEEE802.11g) are not independent because these channels overlap with adjacent channels. In this paper, we propose an extended multi-armed bandit algorithm that uses continuous-valued rewards, which is applicable to wireless communication systems with overlapping channels. We show the effectiveness of the proposed method by experimental demonstrations.

著者

Makoto NARUSE Masashi AONO Song-Ju KIM

出版者

一般社団法人 電子情報通信学会

雑誌

IEICE Transactions on Communications (ISSN:09168516)

巻号頁・発行日

vol.E96.B, no.11, pp.2724-2732, 2013-11-01 (Released:2013-11-01)

参考文献数

34

被引用文献数

1 5

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Nature-inspired devices and architectures are attracting considerable attention for various purposes, including the development of novel computing techniques based on spatiotemporal dynamics, exploiting stochastic processes for computing, and reducing energy dissipation. This paper demonstrates that networks of optical energy transfers between quantum nanostructures mediated by optical near-field interactions occurring at scales far below the wavelength of light could be utilized for solving a constraint satisfaction problem (CSP), the satisfiability problem (SAT), and a decision making problem. The optical energy transfer from smaller quantum dots to larger ones, which is a quantum stochastic process, depends on the existence of resonant energy levels between the quantum dots or a state-filling effect occurring at the larger quantum dots. Such a spatiotemporal mechanism yields different evolutions of energy transfer patterns in multi-quantum-dot systems. We numerically demonstrate that networks of optical energy transfers can be used for solution searching and decision making. We consider that such an approach paves the way to a novel physical informatics in which both coherent and dissipative processes are exploited, with low energy consumption.