👉 Cablegrams are a type of video transmission format that utilizes a proprietary, high-speed optical fiber signal to transmit data from one point to another. The term "cablegram" is often used in the context of television, where it refers to a small, portable device used for viewing live sports and other events through cable TV. In this context, a "cablegram" would typically refer to a small device or an optical fiber signal that is transmitted over a high-speed optical fiber link.