Faculty Profiles - MURASE Tutomu

Papers - MURASE Tutomu

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Evaluating effect of interference on MAC delay in densely deployed IEEE 802.11ad based In-vehicle communications Reviewed

Shiohara T., Nishio T., Murase T.

2021 IEEE International Conference on Consumer Electronics-Taiwan, ICCE-TW 2021 2021

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：2021 IEEE International Conference on Consumer Electronics-Taiwan, ICCE-TW 2021

This paper evaluates MAC-layer delay of IEEE 802.11ad based In-vehicle communications, where strong interference from multiple devices on own and other vehicles could occur stochastically due to beamforming. The wide frequency bandwidth of IEEE 802.11ad is expected to enable ultra-low latency in-vehicle communications. However, the beamforming of IEEE 802.11ad causes strong interference and could degrade the delay performance. To investigate the impact of the beamforming interference on delay performance, we conducted network simulations using ns3. The results show that a control method, fixed contention window (CW), achieved the maximum delay of 2 msec, whereas conventional control method, Distributed Coordination Function (DCF), did larger delay of 12 msec.

DOI： 10.1109/ICCE-TW52618.2021.9603150

Scopus

Effective collaboration to maximize throughput based on multiuser cooperative mobility in social-physical Ad Hoc Networks Reviewed

Xie J., Murase T.

IEEE Open Journal of the Communications Society Vol. 2 page： 818 - 835 2021

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：IEEE Open Journal of the Communications Society

Social networks are playing an increasingly important role in information dissemination in wireless ad hoc networks with the wide adoption of the mobile Internet. In particular, in social application scenarios such as Facebook and Twitter, the questions of how to fully consider the social relationships between users to ensure the quality of service (QoS) urgently needs to be explored. This paper investigates an optimal social relay selection scheme with high intimacy requirements to maximize the system throughput for social-physical ad hoc networks with device-to-device (D2D) communication. Different from previous studies, we jointly consider feasible relays and multiuser cooperative mobility with satisfactory link reliability for throughput maximization. On the one hand, we formulate a nonlinear and nonconvex problem, which is typically NP-hard, for throughput optimization. Specifically, this optimization problem is divided into two subproblems: I) selecting the optimal relays and ii) determining the best mobility strategy in terms of throughput. On the other hand, we first convert the relay selection subproblem into an optimal stopping phase problem, and then propose a definition of a graph representing the degrees of interference between physical links, transforming the original optimization problem into a convex problem that is solvable using the Lagrange multiplier method. Based on the above, we propose the Relay selection and Link Interference Degree Graph (RS-LIDG) algorithm to solve the two subproblems. Numerical simulations verify that the proposed RS-LIDG method improves the throughput gain by 26.29%, 123.43%, and 236.47% compared to the intuitive method (IM), the social-trust-based random mobility selection method (STS-RM), and the physical-based random mobility selection method (PHS-RM), respectively.

DOI： 10.1109/OJCOMS.2021.3071853

Scopus

IEEE 802.11ad Communication Quality Measurement in In-vehicle Wireless Communication with Real Machines Reviewed

Nino R., Nishio T., Murase T.

2020 11th IEEE Annual Ubiquitous Computing, Electronics and Mobile Communication Conference, UEMCON 2020 page： 0700 - 0706 2020.10

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：2020 11th IEEE Annual Ubiquitous Computing, Electronics and Mobile Communication Conference, UEMCON 2020

This paper demonstrates the feasibility of IEEE 802.11ad-based in-vehicle communication for a wireless harness. IEEE 802.11ad millimeter-wave (mmWave) communication enables high-speed wireless transmission, and its short communication range prevents harmful interference from other vehicles. However, in an in-vehicle environment, the received power of IEEE 802.11ad-based mmWave communications can be largely and easily attenuated by obstacles such as humans and the vehicle interior. Moreover, mmWave signals from adjacent vehicles can penetrate through vehicle windows and cause harmful interference. In this paper, we report the experimental results of in-vehicle communications using an actual vehicle and IEEE 802.11ad devices in an anechoic chamber. The experimental results demonstrate that IEEE 802.11ad-based in-vehicle communication can achieve a throughput of several hundred megabits per second, which is almost equivalent to that in achieved free space; this throughput can even be achieved when there are multiple obstacles in a vehicle and when adjacent vehicles (i.e., interferers) are in close proximity.

DOI： 10.1109/UEMCON51285.2020.9298087

Scopus

Throughput Measurement of IEEE 802.11ad with Various Interferences on Vehicles

Hirata T., Murase T.

2020 IEEE International Conference on Consumer Electronics - Taiwan, ICCE-Taiwan 2020 2020.9

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：2020 IEEE International Conference on Consumer Electronics - Taiwan, ICCE-Taiwan 2020

IEEE802.11ad wireless LAN (WLAN) set in a vehicle was examined in order to know how much throughput quality was observed in congestion cases. As such a congestion case, two WLAN were used to measure throughput when vehicle frames and windows of a vehicle mitigate interference from other WLANs of other vehicles. Experiments by using real 802.11ad devices were performed and provided many useful qualitative results. For example, throughput degradation by interference is very large, 71.9% with door opened and is still large, 32.1% through glass windows. The results also revealed that steel frame doors are effective enough to shield the interference regardless of glass windows being opened or closed.

DOI： 10.1109/ICCE-Taiwan49838.2020.9258239

Scopus

Cross Layer Downlink Packet Scheduling Method based on Application QoE

SATODA Kozo, NOGAMI Kosuke, SUZUKI Takayuki, TAKAHASHI Eiji, MURASE Tutomu

Vol. J103-B ( 9 ) page： 391 - 406 2020.9

Language：Japanese Publishing type：Research paper (scientific journal)

Thanks to mobile evolution, a lot of mobile applications are used in mobile networks. Conventional mobile networks allocate radio resources to user terminals using expected throughput of each terminal and fairness between terminals. However, it becomes much more important to assure communication quality for each application under the circumstance that users are using a variety of applications. In this paper, we propose a radio resource scheduling method on a base station considering user-experienced quality (QoE) for each application. We aim at increasing users whose experienced quality is higher than a certain threshold, since users tend to dissatisfy and stop communication when QoE is lower than it. We conducted evaluations assuming that users were watching a video and browsing a Web page while they were moving. Evaluation shows that average QoE for Web improves by up to 1.48 point and the number of users whose QoE is more than 3.0 is 2.1 times more than conventional methods.

DOI： 10.14923/transcomj.2020jbp3008

CiNii Research

Throughput Measurement of IEEE 802.11ad with Various Interferences on Vehicles Reviewed

Hirata Tomonori, Murase Tutomu

2020 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS - TAIWAN (ICCE-TAIWAN) 2020

Empowering Vehicular Networks with Computational Intelligence

Celimuge Wu, Tsutomu Yoshinaga, Yusheng Ji, Tutomu Murase

IEICE Technical Report, ICM2019-19 page： 77 - 82 2019.7

Video Streaming Control Based on Communication Throughput Prediction

YOSHIDA Hiroshi, SASAJIMA Kazuyuki, MURASE Tutomu, SATODA Kozo

Vol. J101-B ( 5 ) page： 320 - 337 2018.5

Language：Japanese Publishing type：Research paper (scientific journal)

There are two major challenges in video streaming through the best-effort networks such as the Internet and mobile networks. The first challenge is to improve the users' quality of experience (QoE). The communication throughput fluctuates widely on best-effort networks because of radio interferences and cross-traffic, which causes the video interruption and playout delay. The Second is the utilization efficiency of network resources, which is from a viewpoint of a network operator. The increase of video data size with the evolution of high-resolution video occupies a network resource for a long time and makes network resources seriously tight. Another problem is that the received video data in a playout buffer goes to waste of the network resources when the user stops watching the video in the middle. In this paper, the authors propose a video streaming technology that solves the above two problems by combining a rate control method and a pacing technique based on the communication throughput prediction. By referring to the stochastic diffusion of the future throughput, the rate control selects the maximum bitrate under the condition that the playout interruption is avoided. The authors demonstrate that the proposed method improves the QoE indicator recommended by ITU-T (real number from one to five) by an average of 0.75 compared with the conventional methods. Furthermore, the experience shows that the pacing function improves the duration of opening network resources. Although the playout buffer size of the proposed method increases by 2 〜 3 MB, it is a predicted need to maintain high QoE.

DOI： 10.14923/transcomj.2017mop0001

CiNii Research

モバイルエッジコンピューティングにおけるQoS最適VM移動制御

Jun Kikuchi, Celimuge Wu, Yusheng Ji, Tutomu Murase

IEICE Technical Report Vol. IN2017-98 page： 51 - 56 2018.3

Performance evaluation on multiple ad hoc networks with co-existing aggressive contention window control and legacy control Reviewed

Riku Ohmiya, Hiroyasu Obata, Tutomu Murase

ACM International Conference Proceeding Series 2018.1

Authorship：Corresponding author Language：English Publishing type：Research paper (international conference proceedings) Publisher：Association for Computing Machinery

Device-to-device1 (D2D) technology in fifth-generation wireless communication (5G) can leverage densely deployed multiple ad hoc networks. Much research has been done to improve QoS, such as throughput, which would decrease because of ad hoc networks' interference with each other. We focus here on the capture effect and its impact on the throughput performance. A contention window control method, ACWA, which improves the throughput of ad hoc networks by exploiting intentional collisions, has recently been proposed thanks to the capture effect. However, the unfairness of throughput between ACWA and the Distributed Coordination Function (DCF) might occur because ACWA could be too aggressive. We propose a modified ACWA method (GSAR scheme) that drastically improves the unfairness and keeps throughput as high as ACWA. GSAR just uses DCF at the sending node and uses ACWA in the rest nodes. In our evaluations considering capture effect, Jain's fairness index resulted in 1.0 from 0.56 in two ad hoc networks with DCF and GSAR.

DOI： 10.1145/3164541.3164542

Scopus

Transaction Offloading for Access Management to Live Data of IoT in Information-Centric Network Reviewed

Ito Tomoki, Noguchi Hirofumi, Yamato Yoji, Murase Tutomu

2018 IEEE 7TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE 2018) page： 287 - 288 2018

Efficient Content Delivery in Vehicular Networks with Sub-6 GHz and mmWave

Celimuge Wu, Tsutomu Yoshinaga, Tutomu Murase, Yusheng Ji

IEICE Technical Report Vol. CQ2017-74 page： 23 - 28 2017.11

Validation of Theoretical Evaluation on User Cooperative Mobility for QoS Improvement in Ad-hoc Networks

Luo Tianran, Murase Tutomu

2017 IEEE 6TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE) page： . 2017

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