A solid foundation must be used for building either a wired or wireless LAN. As shown Figure , this foundation is referred to as Layer 1 or the physical layer in the OSI reference model. The physical layer is the layer that defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between end systems.
This section introduces different types of networking media that are used at the physical layer, including:
-shielded twisted-pair cable
-unshielded twisted-pair cable
-coaxial cable
-fiber-optic cable
-propagated radio waves
Radio waves are the medium used by wireless technologies. When designing and building networks, it is important to comply with all applicable fire codes, building codes, and safety standards. Established performance standards should be followed to ensure optimal network operation. Because of the wide variety of options that are currently available in networking media, compatibility and interoperability should also be considered.