Metropolitan area network
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|Computer network types by spatial scope|
A metropolitan area network (MAN) is a computer network in which two or more computers or communicating devices or networks which are geographically separated but in same metropolitan city and are connected to each other are said to be connected on MAN. Metropolitan limits are determined by local municipal corporations; the larger the city, the bigger the MAN, the smaller a metro city, smaller the MAN. 
|“||A MAN is optimized for a larger geographical area than a LAN, ranging from several blocks of buildings to entire cities. MANs can also depend on communications channels of moderate-to-high data rates. A MAN might be owned and operated by a single organization, but it usually will be used by many individuals and organizations. MANs might also be owned and operated as public utilities. They will often provide means for inter networking of local networks.||”|
Kenneth C. Laudan and Jane P. Laudon define a metropolitan area network as:
|“||A Metropolitan Area Network (MAN) is a large computer network that spans a metropolitan area or campus. Its geographic scope falls between a WAN and LAN. MANs provide Internet connectivity for LANs in a metropolitan region, and connect them to wider area networks like the Internet.||”|
Some technologies used for that purpose are Asynchronous Transfer Mode (ATM), FDDI, and SMDS. These technologies are in the process of being displaced by Ethernet-based connections (e.g., Metro Ethernet) in most areas. MAN links between local area networks have been built without cables using either microwave, radio, or infra-red laser links. Most companies rent or lease circuits from common carriers because laying long stretches of cable can be expensive.
Distributed-queue dual-bus (DQDB) refers to the metropolitan area network standard for data communication specified in the IEEE 802.6 standard. With DQDB, networks can extend up to 20 miles (30 km) long and operate at speeds of 34–155 Mbit/s.
- IEEE Std 802-2002, IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture, page 1, section 1.2: "Key Concepts", "basic technologies" http://standards.ieee.org/getieee802/download/802-2001.pdf
- Kenneth C. Laudan and Jane P. Laudon, Management Information Systems: Managing the Digital Firm, 10th ed. (2001).