Study and Demonstration of Sleep and Adaptive Link Rate Control Mechanisms for Energy Efficient 10G-EPON. - Ryogo Kubo; Jun-ichi Kani; Hirotaka Ujikawa; Takeshi Sakamoto; Yukihiro Fujimoto; Naoto Yoshimoto; Hisaya Hadama (JOCN, 2010)

Multilevel dynamic bandwidth allocation using buffer observation for cousin-fair access systems. - Hirotaka Ujikawa; Takeshi Sakamoto; Naoto Yoshimoto; Hisaya Hadama (APCC, 2011)

ONU sleep control by HGW considering users' traffic distribution for energy-aware access networks. - Hiroko Nomura; Susumu Nishihara; Hirotaka Ujikawa; Masashi Tadokoro; Takashi Yamada; Naoto Yoshimoto (APCC, 2012)

Bandwidth scheduling techniques in TDM-PON supporting inter-ONU communication with network coding for smart grid applications. - Ryogo Kubo; Masashi Tadokoro; Hiroko Nomura; Hirotaka Ujikawa; Susumu Nishihara; Ken-Ichi Suzuki; Naoto Yoshimoto (ICC, 2012)

A bandwidth allocation method to improve user QoS satisfaction without decreasing system throughput in wireless access networks. - Kenta Suzuki; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki; Naoto Yoshimoto (PIMRC, 2012)

Demonstration of timer-based ONU deep sleep for emergency communication during power failure. - Hirotaka Ujikawa; Takashi Yamada; Naoto Yoshimoto (GLOBECOM, 2013)

On the effect of cooperation between power saving mechanisms in WLANs and PONs. - Ko Togashi; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki; Naoto Yoshimoto (ICC, 2013)

Smart FiWi Networks: Challenges and Solutions for QoS and Green Communications. - Zubair Md Fadlullah; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki; Naoto Yoshimoto (IEEE Intell. Syst., 2013)

Cooperative QoS Control Scheme Based on Scheduling Information in FiWi Access Network. - Zubair Md Fadlullah; Hiroki Nishiyama 001; Yuichi Kawamoto; Hirotaka Ujikawa; Ken-Ichi Suzuki; Naoto Yoshimoto (IEEE Trans. Emerg. Top. Comput., 2013)

Cross Layer Analysis on ONU Energy Consumption in Smart FiWi Networks. - Ko Togashi; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki; Naoto Yoshimoto (IEEE Wirel. Commun. Lett., 2013)

Coordinating energy-efficient CPEs on IEEE 1904.1 compliant systems Via ONU for enhanced power savings: Proposal and demonstration. - Hiroko Nomura; Hiroyuki Uzawa; Yuki Arikawa; Yukikuni Nishida; Hirotaka Ujikawa; Ken-Ichi Suzuki; Naoto Yoshimoto (ICC, 2014)

Synchronized Power Saving Mechanisms for Battery-Powered Mobile Terminals in Smart FiWi Networks. - Keisuke Miyanabe; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki; Naoto Yoshimoto (VTC Fall, 2014)

Average rate analysis for a D2D overlaying two-tier downlink cellular network. - Shangwei Zhang; Jiajia Liu 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki (ICC, 2015)

A novel network design and operation for reducing transmission power in cloud radio access network with power over fiber. - Yunseong Lee; Katsuya Suto; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki (ICCC, 2015)

Integrated Dynamic Bandwidth Allocation for Low Buffer Aggregated Passive Optical Network Systems. - Hiroshi Ou; Yoshihito Sakai; Hirotaka Ujikawa; Takuya Tsutsumi; Toshihito Fujiwara; Yasutaka Kimura; Takeshi Sakamoto; H. Suzuki; Jun Terada; Akihiro Otaka (JOCN, 2015)

Device-to-device communications for enhancing quality of experience in software defined multi-tier LTE-A networks. - Jiajia Liu 001; Shangwei Zhang; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki (IEEE Netw., 2015)

QoE-Guaranteed and Power-Efficient Network Operation for Cloud Radio Access Network With Power Over Fiber. - Katsuya Suto; Keisuke Miyanabe; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki (IEEE Trans. Comput. Soc. Syst., 2015)

A cloud radio access network with power over fiber toward 5G networks: QoE-guaranteed design and operation. - Keisuke Miyanabe; Katsuya Suto; Zubair Md Fadlullah; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki (IEEE Wirel. Commun., 2015)

A MPCP-Based Centralized Rate Control Method for Mobile Stations in FiWi Access Networks. - Kei Saito; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki (IEEE Wirel. Commun. Lett., 2015)

QoE-Guaranteed and Sustainable User Position Guidance for Post-Disaster Cloud Radio Access Network. - Katsuya Suto; Tiago Gama Rodrigues; Hiroki Nishiyama 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki (GLOBECOM, 2016)

New Perspectives on Future Smart FiWi Networks: Scalability, Reliability, and Energy Efficiency. - Jiajia Liu 001; Hongzhi Guo; Hiroki Nishiyama 001; Hirotaka Ujikawa; Ken-Ichi Suzuki; Nei Kato (IEEE Commun. Surv. Tutorials, 2016)

Energy-Efficient Service Multiplexing on Profile-Based TWDM Access Systems. - Hirotaka Ujikawa; Ken-Ichi Suzuki; Akihiro Otaka; Hiroki Nishiyama 001; Nei Kato (IEEE Internet Things J., 2016)

Stand-Alone and Cooperative Deep Sleep for Battery-Driven Optical Network Unit. - Hirotaka Ujikawa; Takashi Yamada; Ken-Ichi Suzuki; Akihiro Otaka; Hiroki Nishiyama 001; Nei Kato (IEEE Internet Things J., 2016)

Device-to-Device Communication for Mobile Multimedia in Emerging 5G Networks. - Jiajia Liu 001; Nei Kato; Hirotaka Ujikawa; Ken-Ichi Suzuki (ACM Trans. Multim. Comput. Commun. Appl., 2016)

Flexible Access System Architecture to Support Diverse Requirements and Agile Service Creation. - Junichi Kani; Manabu Yoshino; Toshikiyo Tanaka; Kota Asaka; Hirotaka Ujikawa; Ken-Ichi Suzuki; Akihiro Otaka (ECOC, 2017)

Efficient DWBA Algorithm for TWDM-PON with Mobile Fronthaul in 5G Networks. - Yu Nakayama; Hiroyuki Uzawa; Daisuke Hisano; Hirotaka Ujikawa; Hirotaka Nakamura; Jun Terada; Akihiro Otaka (GLOBECOM, 2017)

Dynamic software updating of OLTs without service interruption. - Takumi Harada; Hirotaka Ujikawa; Manabu Yoshino; Noriyuki Oota; Ken-Ichi Suzuki; Akihiro Otaka (SoftCOM, 2017)

Flexible Access System Architecture (FASA). - Kota Asaka; Hirotaka Ujikawa; Junichi Kani; Akihiro Otaka (OFC, 2018)

In-Service Software Updating without Packet Loss for a Time-Critical Function on Optical Access Network System. - Takumi Harada; Takashi Yamada; Hirotaka Ujikawa; Hiroyuki Uzawa; Junichi Kani; Jun Terada (OFC, 2019)

Disaggregation of Time-Critical Applications in Flexible Access System Architecture [Invited]. - Kota Asaka; Hirotaka Ujikawa; Hiroyuki Uzawa; Hirotaka Nakamura; Jun-ichi Kani; Akihiro Otaka; Jun Terada (JOCN, 2019)

Proactive congestion control within 1-ms delay at mobile midhaul utilizing parallel traffic prediction and fast switchover of CU and optical path. - Yuka Okamoto; Hirotaka Ujikawa; Kota Asaka; Tatsuya Shimada; Tomoaki Yoshida (OFC, 2024)

User-dedicated optical path switching with optical-wireless cooperative control for low-latency and seamless handover. - Kenji Miyamoto; Hirotaka Ujikawa; Tatsuya Shimada; Tomoaki Yoshida (J. Opt. Commun. Netw., 2024)

Real-time optical-wireless cooperative switching on wireless quality degradation for end-to-end video delay guarantee. - Hirotaka Ujikawa; Yuka Okamoto; Takumi Harada; Tatsuya Shimada; Tomoaki Yoshida (J. Opt. Commun. Netw., 2024)

Experimental Evaluation of an SDN Controller for Open Optical-circuit-switched Networks. - Kazuya Anazawa; Takeru Inoue; Toru Mano; Hiroshi Ou; Hirotaka Ujikawa; Dmitrii Briantcev; Sumaiya Binte Ali; Devika Dass; Hideki Nishizawa; Yoshiaki Sone; Eoin Kenny; Marco Ruffini; et al. (CoRR, 2025)