Major communication tools for air traffic control (ATC) and management (ATM) is still verbal-based system while digital communication system has been widely used in the other fields. Although some digital communication tools have been gradually and partially employed even in ATC system, digitalization of the communication systems for air traffic control is quite limited which will be promising technologies for enhancing efficiency and safety of ATC/ATM. This paper firstly summarizes the progress and issues of the communication system for ATC/ATM in Japan. Secondly, the demand and capacity balance for digital satellite communication system is analyzed based on the future air traffic demand prediction in Tokyo metropolitan airspace. Finally, the future direction and challenges for developing digital communication infrastructure for ATC/ATM are discussed based on the results of demand and capacity balance.

現在の情報技術の爆発的発展は，符号化技術の支えをなくしてはありえない．本稿では，情報伝送のための通信路符号化技術を量子限界まで拡張した量子通信路符号化技術について解説する．これは現在の光通信から量子情報通信のパラダイムに向けて最も自然な形で移行してゆく際の最初の通過点である．その基本概念と実用的な意味，原理実証に関する研究の現状，および実用化へ向けた課題を展望する．