Classifying Networks by Scale

Not all networks are created equal. One of the most fundamental ways to classify them is by their geographical scope-the physical area they cover. This classification helps us understand the purpose, technology, and complexity of different types of networks. We can categorize them into four main types, from the personal space around you to the entire globe.

PAN (Personal Area Network)

A Personal Area Network (PAN) is the smallest type of network, typically used in homes and small offices.

• Range: It has a very small geographical range, typically up to about 10 meters (33 feet).
• Primary Goal: Its main purpose is to enable communication for a single individual, connecting a computer with its peripherals (like printers and scanners) and other personal devices such as laptops, palmtops, mobile phones, and VoIP phones.
• Transmission Media: PANs utilize a variety of transmission media, both wired and wireless. Common examples include:
  • Unshielded Twisted Pair (UTP) cables (less common for PANs).
  • Wireless technologies like WLAN (Wi-Fi), Bluetooth, and Infrared.

LAN (Local Area Network)

A Local Area Network (LAN) is the most common type of network found within a single organization or building.

• Scope: A LAN covers a single building or a group of buildings within a small area, like a school campus or an office park.
• Application: Used to connect personal computers and workstations to share resources (like files and printers) and exchange information.
• Reliability: Local networks are characterized by very high operational reliability.
• Schema: The typical modern LAN is built in a star topology, with computers connected to a central device like a switch.

MAN (Metropolitan Area Network)

A Metropolitan Area Network (MAN) bridges the gap between LANs and WANs.

• Definition: A MAN connects separate LANs within the area of a single city or an agglomeration, enabling internet access for individual computers, primarily for private users.
• Construction: Metropolitan networks are typically based on a high-speed backbone network, often a fiber-optic ring structure. This backbone connects various network nodes distributed throughout the city.
• Technology: MANs commonly use high-speed protocols like Ethernet, with capacities ranging from 100 Mb/s to 10 Gb/s or more. Their users include institutions from all spheres of economic and social activity.
• Example: A prominent example is a city-wide fiber optic network built by a service provider to connect various business LANs, government buildings, and university campuses to the internet and to each other.

WAN (Wide Area Network)

A Wide Area Network (WAN) is the largest type of network, connecting LANs and MANs on a national, continental, or global scale.

• Other terms: WANs are often referred to as "long-haul networks."
• Characteristics: WAN connections are often associated with lower throughput compared to LANs and are typically managed by multiple service providers.
• The Ultimate Example: The Internet is the largest WAN in the world.
• Other Examples: National Research and Education Networks (NRENs) like Internet2 in the US or GÉANT in Europe are WANs connecting academic institutions. Large multinational corporations also operate private WANs to connect their global offices.