GY—room (field) optical cable for communication; GR—soft optical cable for communication; GJ - optical cable in communication room (office); GS - optical cable in communication equipment; GH - submarine optical cable for communication; GT - special optical. GY—room (field) optical cable for communication; GR—soft optical cable for communication; GJ - optical cable in communication room (office); GS - optical cable in communication equipment; GH - submarine optical cable for communication; GT - special optical. ITU-T has been active in the standardization of optical communications technology and the techniques for its optimal application within networks from the infancy of this industry. However, it is not always easy to find out what has been covered, and where it can be found. This manual attempts to. Fiber optic cables provide versatility and durability in a wide range of applications and are critical for ensuring the reliability of communication networks all over the world. It provides high performance, high bandwidth, high speed and low data loss. As you know, we can use twisted pair copper cables for short. In the landscape of network infrastructure, three primary cable categories dominate connectivity: twisted-pair copper cables, coaxial cables, and fiber optic cables. While copper-based solutions (such as Cat5e/Cat6 for twisted pair or RG-6 for coaxial) have long served as workhorses for local and. Let's take a look at the meanings of the fiber optic cable models.