HYAT23 is an urban telecommunication cable with solid polyolefin insulated copper conductors, jelly-filled construction, a moisture-barrier PE jacket, steel tape armor and a PE outer jacket. It adopts a double-jacket structure: the first layer is a PE jacket with a longitudinally applied aluminum-plastic composite tape as the moisture barrier; the second layer is steel tape armor covered with an outer PE jacket. The cable is filled with petroleum jelly. It is mainly used for transmitting audio, analog signals at 150kHZ and below, and digital signals at 2048kbit/s and below. Under certain conditions, it can also be used to transmit digital signals above 2048kbit/s.