Research on congestion control in LPWA networks to suppress overload of IoT systems.

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K04471
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21020:Communication and network engineering-related
• Research Institution: Nippon Institute of Technology
• Principal Investigator: Yoshino Hideaki 日本工業大学, 先進工学部, 教授 (00644816)
• Co-Investigator(Kenkyū-buntansha): 山本 幹 関西大学, システム理工学部, 教授 (30210561) ; 平栗 健史 日本工業大学, 基幹工学部, 教授 (90582817) ; 大田 健紘 日本工業大学, 基幹工学部, 助教 (50511911) ; 伊藤 暢彦 日本工業大学, 先進工学部, 准教授 (40706032)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: ネットワーク / センサ / 輻輳制御 / トラヒック / IoT

Outline of Final Research Achievements

This research aims to establish congestion control schemes to suppress temporal and spatial traffic overload as a basic technology for controlling the future IoT systems. Firstly, we proposed a control scheme to suppress congestion in random access channels caused by the concentration of outgoing signals from IoT devices in LPWA networks by regulating outgoing signals. Throughput characteristics of the proposed congestion control scheme are clarified by theoretical analysis and simulations, the results showed that the proposed scheme can provide stable control even under overload. Secondary, we proposed an aggregation number control that sets an upper limit on the data aggregation time in an IoT gateway and verified its effectiveness. Thirdly, in the TCP in IoT environment, we demonstrated the issue of performance degradation of TCP congestion control due to slow access links and clarified that there is adequate NIC buffer size based on the IoT application requirements.

Free Research Field

情報学

Academic Significance and Societal Importance of the Research Achievements

IoTシステムにおけるセンサ側の情報処理性能の制約の下、LPWA親機側との機能分担を考慮した有効な輻輳制御方式を考案した点、今後のIoTシステムの普及・進展を見据え、広域災害時など緊急時こそ有効に機能する安定した方式を提案した点、低速リンクで多数のセンサを収容するIoT特有のシステム環境から生じるTCP輻輳制御の課題を見出し、ネットワークインタフェース層のバッファ設計指針等を明らかにした点において学術的及び社会的意義が大きいと考える。