Final answer:
The Invisilight MDU Hallway Solution employs optical fibres within a multi-fibre cord, using the principle of total internal reflection for light transmission.
Step-by-step explanation:
The Invisilight MDU Hallway Solution contains an unspecified number of optical fibres within a specific multi-fibre cord. This technology is part of fibre optics, which involves the transmission of light down fibers made of plastic or glass by applying the principle of total internal reflection. The actual number of fibers can vary depending on the configuration and requirements of the installation. Fiber optic technology is essential for efficient and high-speed data transmission, making it critical for modern communication networks.