Hirotaka Ujikawa

36 papers B 4C 3Misc 1Journal 18Unranked 10
YearRankTypeTitle / Venue / Authors
2025 — conf
Application-Level E2E Demonstration of Reducing Uplink Jitter Due to Radio Transmission Toward Real-Time and Stable Remote Operation.
VTC2025-Spring
Kenji Miyamoto, Takumi Harada, Hirotaka Ujikawa, Tatsuya Shimada, Tomoaki Yoshida
2025 J jnl
Experimental Evaluation of an SDN Controller for Open Optical-circuit-switched Networks.
CoRR
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, Daniel C. Kilper, Eiji Oki, Koichi Takasugi
2025 J jnl
Traffic Classification Method Using Spectrum Analysis for Proactive Congestion Control in Radio Access Network.
IEEE Access
Yuka Okamoto, Hirotaka Ujikawa, Kenji Miyamoto, Tomoya Hatano, Tatsuya Shimada
2024 — conf
Proactive congestion control within 1-ms delay at mobile midhaul utilizing parallel traffic prediction and fast switchover of CU and optical path.
OFC
Yuka Okamoto, Hirotaka Ujikawa, Kota Asaka, Tatsuya Shimada, Tomoaki Yoshida
2024 J jnl
Real-time optical-wireless cooperative switching on wireless quality degradation for end-to-end video delay guarantee.
J. Opt. Commun. Netw.
Hirotaka Ujikawa, Yuka Okamoto, Takumi Harada, Tatsuya Shimada, Tomoaki Yoshida
2024 J jnl
User-dedicated optical path switching with optical-wireless cooperative control for low-latency and seamless handover.
J. Opt. Commun. Netw.
Kenji Miyamoto, Hirotaka Ujikawa, Tatsuya Shimada, Tomoaki Yoshida
2019 J jnl
Disaggregation of Time-Critical Applications in Flexible Access System Architecture [Invited].
JOCN
Kota Asaka, Hirotaka Ujikawa, Hiroyuki Uzawa, Hirotaka Nakamura, Jun-ichi Kani, Akihiro Otaka, Jun Terada
2019 — conf
In-Service Software Updating without Packet Loss for a Time-Critical Function on Optical Access Network System.
OFC
Takumi Harada, Takashi Yamada, Hirotaka Ujikawa, Hiroyuki Uzawa, Junichi Kani, Jun Terada
2018 — conf
Flexible Access System Architecture (FASA).
OFC
Kota Asaka, Hirotaka Ujikawa, Junichi Kani, Akihiro Otaka
2017 Misc conf
Dynamic software updating of OLTs without service interruption.
SoftCOM
Takumi Harada, Hirotaka Ujikawa, Manabu Yoshino, Noriyuki Oota, Ken-Ichi Suzuki, Akihiro Otaka
2017 B conf
Efficient DWBA Algorithm for TWDM-PON with Mobile Fronthaul in 5G Networks.
GLOBECOM
Yu Nakayama, Hiroyuki Uzawa, Daisuke Hisano, Hirotaka Ujikawa, Hirotaka Nakamura, Jun Terada, Akihiro Otaka
2017 — conf
Flexible Access System Architecture to Support Diverse Requirements and Agile Service Creation.
ECOC
Junichi Kani, Manabu Yoshino, Toshikiyo Tanaka, Kota Asaka, Hirotaka Ujikawa, Ken-Ichi Suzuki, Akihiro Otaka
2016 J jnl
Device-to-Device Communication for Mobile Multimedia in Emerging 5G Networks.
ACM Trans. Multim. Comput. Commun. Appl.
Jiajia Liu, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki
2016 J jnl
Energy-Efficient Service Multiplexing on Profile-Based TWDM Access Systems.
IEEE Internet Things J.
Hirotaka Ujikawa, Ken-Ichi Suzuki, Akihiro Otaka, Hiroki Nishiyama, Nei Kato
2016 J jnl
New Perspectives on Future Smart FiWi Networks: Scalability, Reliability, and Energy Efficiency.
IEEE Commun. Surv. Tutorials
Jiajia Liu, Hongzhi Guo, Hiroki Nishiyama, Hirotaka Ujikawa, Ken-Ichi Suzuki, Nei Kato
2016 B conf
QoE-Guaranteed and Sustainable User Position Guidance for Post-Disaster Cloud Radio Access Network.
GLOBECOM
Katsuya Suto, Tiago Gama Rodrigues, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki
2016 J jnl
Stand-Alone and Cooperative Deep Sleep for Battery-Driven Optical Network Unit.
IEEE Internet Things J.
Hirotaka Ujikawa, Takashi Yamada, Ken-Ichi Suzuki, Akihiro Otaka, Hiroki Nishiyama, Nei Kato
2015 J jnl
A MPCP-Based Centralized Rate Control Method for Mobile Stations in FiWi Access Networks.
IEEE Wirel. Commun. Lett.
Kei Saito, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki
2015 J jnl
A cloud radio access network with power over fiber toward 5G networks: QoE-guaranteed design and operation.
IEEE Wirel. Commun.
Keisuke Miyanabe, Katsuya Suto, Zubair Md Fadlullah, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki
2015 C conf
A novel network design and operation for reducing transmission power in cloud radio access network with power over fiber.
ICCC
Yunseong Lee, Katsuya Suto, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki
2015 — conf
Average rate analysis for a D2D overlaying two-tier downlink cellular network.
ICC
Shangwei Zhang, Jiajia Liu, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki
2015 J jnl
Device-to-device communications for enhancing quality of experience in software defined multi-tier LTE-A networks.
IEEE Netw.
Jiajia Liu, Shangwei Zhang, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki
2015 J jnl
Integrated Dynamic Bandwidth Allocation for Low Buffer Aggregated Passive Optical Network Systems.
JOCN
Hiroshi Ou, Yoshihito Sakai, Hirotaka Ujikawa, Takuya Tsutsumi, Toshihito Fujiwara, Yasutaka Kimura, Takeshi Sakamoto, H. Suzuki, Jun Terada, Akihiro Otaka
2015 J jnl
QoE-Guaranteed and Power-Efficient Network Operation for Cloud Radio Access Network With Power Over Fiber.
IEEE Trans. Comput. Soc. Syst.
Katsuya Suto, Keisuke Miyanabe, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki
2014 — conf
Coordinating energy-efficient CPEs on IEEE 1904.1 compliant systems Via ONU for enhanced power savings: Proposal and demonstration.
ICC
Hiroko Nomura, Hiroyuki Uzawa, Yuki Arikawa, Yukikuni Nishida, Hirotaka Ujikawa, Ken-Ichi Suzuki, Naoto Yoshimoto
2014 — conf
Synchronized Power Saving Mechanisms for Battery-Powered Mobile Terminals in Smart FiWi Networks.
VTC Fall
Keisuke Miyanabe, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki, Naoto Yoshimoto
2013 J jnl
Cooperative QoS Control Scheme Based on Scheduling Information in FiWi Access Network.
IEEE Trans. Emerg. Top. Comput.
Zubair Md Fadlullah, Hiroki Nishiyama, Yuichi Kawamoto, Hirotaka Ujikawa, Ken-Ichi Suzuki, Naoto Yoshimoto
2013 J jnl
Cross Layer Analysis on ONU Energy Consumption in Smart FiWi Networks.
IEEE Wirel. Commun. Lett.
Ko Togashi, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki, Naoto Yoshimoto
2013 B conf
Demonstration of timer-based ONU deep sleep for emergency communication during power failure.
GLOBECOM
Hirotaka Ujikawa, Takashi Yamada, Naoto Yoshimoto
2013 — conf
On the effect of cooperation between power saving mechanisms in WLANs and PONs.
ICC
Ko Togashi, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki, Naoto Yoshimoto
2013 J jnl
Smart FiWi Networks: Challenges and Solutions for QoS and Green Communications.
IEEE Intell. Syst.
Zubair Md Fadlullah, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki, Naoto Yoshimoto
2012 B conf
A bandwidth allocation method to improve user QoS satisfaction without decreasing system throughput in wireless access networks.
PIMRC
Kenta Suzuki, Hiroki Nishiyama, Nei Kato, Hirotaka Ujikawa, Ken-Ichi Suzuki, Naoto Yoshimoto
2012 — conf
Bandwidth scheduling techniques in TDM-PON supporting inter-ONU communication with network coding for smart grid applications.
ICC
Ryogo Kubo, Masashi Tadokoro, Hiroko Nomura, Hirotaka Ujikawa, Susumu Nishihara, Ken-Ichi Suzuki, Naoto Yoshimoto
2012 C conf
ONU sleep control by HGW considering users' traffic distribution for energy-aware access networks.
APCC
Hiroko Nomura, Susumu Nishihara, Hirotaka Ujikawa, Masashi Tadokoro, Takashi Yamada, Naoto Yoshimoto
2011 C conf
Multilevel dynamic bandwidth allocation using buffer observation for cousin-fair access systems.
APCC
Hirotaka Ujikawa, Takeshi Sakamoto, Naoto Yoshimoto, Hisaya Hadama
2010 J jnl
Study and Demonstration of Sleep and Adaptive Link Rate Control Mechanisms for Energy Efficient 10G-EPON.
JOCN
Ryogo Kubo, Jun-ichi Kani, Hirotaka Ujikawa, Takeshi Sakamoto, Yukihiro Fujimoto, Naoto Yoshimoto, Hisaya Hadama