Fundamentals of Wireless Networks

Wireless networks can be divided into two broad segments: short-range and long-range. Short-range wireless pertains to networks that are confined to a limited area. This applies to local area networks (LANs), such as corporate buildings, school campuses, manufacturing plants or homes, as well as to personal area networks (PANs) where portable computers within close proximity to one another need to communicate.

These networks typically operate over unlicensed spectrum reserved for industrial, scientific, medical (ISM) usage. The available frequencies differ from country to country. The most common frequency band is at 2.4 GHz, which is available across most of the globe. Other bands at 5 GHz and 40 GHz are also often used. The availability of these frequencies allows users to operate wireless networks without obtaining a license, and without charge.

Long-range networks continue where LANs end. Connectivity is typically provided by companies that sell the wireless connectivity as a service. These networks span large areas such as a metropolitan area, a state or province, or an entire country. The goal of long-range networks is to provide wireless coverage globally. The most common longrange network is wireless wide area network (WWAN). When true global coverage is required, satellite networks are also available.