37 Installation of structured cabling, fiber optic cable, and cable for telecommunications; Telecommunication wiring services, namely, providing fiber optic network wiring services in the nature of fusion splicing, laying of structured cable, fiber optic cable, and cable for telecommunications, and aerial and underground fiber optic cable, structured cable, and cable for telecommunications placement; Directional drilling, missile bore drilling, and trenching for installing structured cabling, fiber optic cable, and cable for telecommunications; Excavation services; Installation, service, and maintenance of security systems, audio-visual systems, and fire detection systems