This document outlines the recommendations for single-mode optical fiber cables used in telecommunication networks within buildings, focusing on their mechanical and environmental characteristics. Lithuania's plan for the ultra-fast broadband development aims to provide 100 Mbps by 2027 to households and public institutions in cities and rural areas. Lithuania's Ministry of Transport and Communications (Susisiekimo ministerija) is responsible for state policy in the area of digital. Optical Fiber Core could be applied as G. A2, OM1, OM2, OM3, OM4 according to needs. Standard: TS EN 60794 +20 C -20 C +70 C +20 C -Number of cycles: 2 turns -Time per each step: 12 hrs. Suitable. A procurement-friendly, engineer-approved blueprint to select RS-485, KNX/EIB, control, Ethernet, coax, and fiber cabling for HVAC, lighting, access control, fire & safety, and building networks—optimized for reliability, maintainability, and lifecycle cost. This step was important for the development of a common urban communication infrastructure and, in particular for the. Telecentras is a Lithuanian state-owned joint-stock company that offers a range of services including radio and television program transmission, data transmission, internet services, smart television, telephony services, and data center solutions. This project will drive Lithuania forward into the digital future, expanding internet.