氏名

Fatema AKHTER授与した学位博士

専攻分野の名称

工学

学位授与番号

博甲第学位授与の日付

２０２４年 ３月 ２５日

学位授与の要件

自然科学研究科

７０４８号

産業創成工学専攻（学位規則第４条第１項該当）

学位論文の題目

A Study of Model-Based Interface Setup Optimization Algorithm for Concurrently
Communicating Access Points in Wireless Local Area Network（モデルベースによる無線 LAN の同時通信のためのアクセスポイントの通信インターフェース設定最適化アルゴリズムの研究）

論文審査委員

教授

舩曵信生

教授

田野 哲

教授

野上保之

学位論文内容の要旨
This research provides valuable insights and practical solutions for wireless local area network (WLAN) performanceby proposing a model-based approach by optimizing the access point (AP) interface setup.
First, the feasibility of combined assignment of channel bonding (CB) and non-CB channels, along with appropriate
transmission power settings for concurrently communicating APs, was verified through extensive experiments.
The results demonstrated improved network performance. However, this approach required numerous physicalmeasurements of received signal strength (RSS) to calculate the signal-to-interference ratio (SIR). To address thislimitation, an AP interface setup optimization method using throughput estimation for dense WLAN is proposed. The
method selects the CB/non-CB channel and the maximum/minimum transmission power for each AP to maximize SIR.
This model-based method eliminates the requirement of RSS measurements for different channel and power
combinations. The effectiveness of the model-based power-channel assignment approach was then verified throughtestbed experiments and simulations in different network topologies at Okayama University, Japan, and Jatiya Kabi Kazi
Nazrul University, Bangladesh. The results confirmed the effectiveness of the proposed algorithm in improving
performance at any network environments.
This thesis is organized as follows: Chapter 1 introduces the background, motivation, and the contributions of the study
in this thesis. Chapter 2 introduces IEEE 802.11 wireless network technologies related to this thesis, including featuresof the IEEE 802.11n protocol and software tools in the Linux operating system. Chapter 3 reviews the previous studies
related to this thesis and identifies its limitations. Chapter 4 proposes the AP interface setup optimization algorithm for
concurrently communicating APs using a throughput estimation model. Chapter 5 evaluates the proposal throughextensive experiments using real network testbeds. Chapter 6 applies the model-based method to a new network
configuration and evaluates its adaptability performance using simulation. Chapter 7 reviews relevant works inliterature. Finally, Chapter 8 concludes this thesis with some future works.

論文審査結果の要旨
In this thesis, the applicant presented valuable insights and practical solutions for wireless local area network (WLAN)
performance by proposing a model-based approach by optimizing the access point (AP) interface setup. First, thefeasibility of combined assignment of channel bonding (CB) and non-CB channels, along with appropriate transmission
power settings for concurrently communicating APs, was verified through extensive experiments. The results
demonstrated improved network performance. However, this approach required numerous physical measurements ofreceived signal strength (RSS) to calculate the signal-to-interference ratio (SIR). To address this limitation, an APinterface setup optimization method using throughput estimation for dense WLAN was proposed. The method selects
the CB/non-CB channel and the maximum/minimum transmission power for each AP to maximize SIR. This modelbased method eliminates the requirement of RSS measurements for different channel and power combinations. The
effectiveness of the model-based power-channel assignment approach was then verified through testbed experiments
and simulations in different network topologies at Okayama University, Japan, and Jatiya Kabi Kazi Nazrul University,
Bangladesh. The results confirmed the effectiveness of the proposed algorithm in improving performance at any network
environments.
The applicant has published one journal paper, two international conference papers, and two domestic conference
papers to present the contributions.
From the overall evaluation of this thesis, the applicant has satisfied the qualification condition for the doctor degree
in Engineering from the Graduate School of Natural Science and Technology at Okayama University.