A telecommunications network is a collection

Collection

Collection or Collections may refer to:* Collection , the abstract concept of collections in computer science* Collection , the actions of a creditor seeking to recoup a debt...

 of terminals

Terminal (telecommunication)

In the context of telecommunications, a terminal is a device which is capable of communicating over a line. Examples of terminals are telephones, fax machines, and network devices - printers and workstations....

, links

Link (telecommunications)

In telecommunications a link is the communications channel that connects two or more communicating devices. This link may be an actual physical link or it may be a logical link that uses one or more actual physical links...

 and nodes

Node (networking)

In communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...

 which connect together to enable telecommunication

Telecommunication

Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

 between users of the terminals. Networks may use circuit switching

Circuit switching

Circuit switching is a methodology of implementing a telecommunications network in which two network nodes establish a dedicated communications channel through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the...

 or message switching

Message switching

In telecommunications, message switching was the precursor of packet switching, where messages were routed in their entirety, one hop at a time. It was first introduced by Leonard Kleinrock in 1961. Message switching systems are nowadays mostly implemented over packet-switched or circuit-switched...

. Each terminal in the network must have a unique address

Network address

Network address may refer to:*Base address*Classful address*IP address*IPX address*Logical address*Network layer address,*X.25/X.21 address*MAC address-See also:*Autonomous system *Host address*Link layer*Subnet mask...

 so messages or connections can be routed to the correct recipients. The collection of addresses in the network is called the address space

Address space

In computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity.- Overview :...

.

The links connect the nodes together and are themselves built upon an underlying transmission network

Transmission (telecommunications)

Transmission, in telecommunications, is the process of sending, propagating and receiving an analogue or digital information signal over a physical point-to-point or point-to-multipoint transmission medium, either wired, optical fiber or wireless...

 which physically pushes the message across the link.

Examples of telecommunications networks are:

• computer network
  Computer network
  A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
  
  s
• the Internet
  Internet
  The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
  
  
• the telephone network
  Telephone network
  A telephone network is a telecommunications network used for telephone calls between two or more parties.There are a number of different types of telephone network:...
  
  
• the global Telex
  Telex
  Telex may refer to:* Telex , , a communications network** Teleprinter, the device used on the above network* Telex , a Belgian pop group...
  
   network
• the aeronautical ACARS network

Messages and protocols

Messages are generated by a sending terminal, then pass through the network of links and nodes until they arrive at the destination terminal. It is the job of the intermediate nodes to handle the messages and route

Routing

Routing is the process of selecting paths in a network along which to send network traffic. Routing is performed for many kinds of networks, including the telephone network , electronic data networks , and transportation networks...

 them down the correct link toward their final destination.

The messages consist of control (or signaling) and bearer parts which can be sent together or separately. The bearer part is the actual content that the user wishes to transmit (e.g. some encoded speech, or an email) whereas the control part instructs the nodes where and possibly how the message should be routed through the network. A large number of protocols

Protocol stack

The protocol stack is an implementation of a computer networking protocol suite. The terms are often used interchangeably. Strictly speaking, the suite is the definition of the protocols, and the stack is the software implementation of them....

 have been developed over the years to specify how each different type of telecommunication network should handle the control and bearer messages to achieve this efficiently.

Components

All telecommunication networks are made up of five basic components that are present in each network environment regardless of type or use. These basic components include terminals, telecommunications processors, telecommunications channels, computers, and telecommunications control software.

• Terminals
  Terminal (telecommunication)
  In the context of telecommunications, a terminal is a device which is capable of communicating over a line. Examples of terminals are telephones, fax machines, and network devices - printers and workstations....
  
   are the starting and stopping points in any telecommunication network environment. Any input or output device that is used to transmit or receive data can be classified as a terminal component.

• Telecommunications processors support data transmission
  Data transmission
  Data transmission, digital transmission, or digital communications is the physical transfer of data over a point-to-point or point-to-multipoint communication channel. Examples of such channels are copper wires, optical fibres, wireless communication channels, and storage media...
  
   and reception between terminals and computers by providing a variety of control and support functions. (i.e. convert data from digital to analog and back)

• Telecommunications channels are the way by which data is transmitted and received. Telecommunication channels are created through a variety of media of which the most popular include copper wires and coaxial cables (structured cabling
  Structured cabling
  Structured cabling is building or campus telecommunications cabling infrastructure that consists of a number of standardized smaller elements called subsystems.Structured cabling falls into six subsystems:...
  
  ). Fiber-optic cables are increasingly used to bring faster and more robust connections to businesses and homes.

• In a telecommunication environment computers are connected through media to perform their communication assignments.

• Telecommunications control software is present on all networked computers and is responsible for controlling network activities and functionality.

Early networks were built without computers, but late in the 20th century their switching centers were computerized or the networks replaced with computer networks.

Network structure

In general, every telecommunications network conceptually consists of three parts, or planes (so called because they can be thought of as being, and often are, separate overlay network

Overlay network

An overlay network is a computer network which is built on the top of another network. Nodes in the overlay can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network...

s):

• The control plane
  Control plane
  In routing, the control plane is the part of the router architecture that is concerned with drawing the network map, or the information in a routing table that defines what to do with incoming packets. Control plane functions, such as participating in routing protocols, run in the architectural...
  
   carries control information (also known as signalling).
• The data plane or user plane or bearer plane carries the network's users traffic.
• The management plane carries the operations and administration traffic required for network management
  Network management
  Network management refers to the activities, methods, procedures, and tools that pertain to the operation, administration, maintenance, and provisioning of networked systems....
  
  .

Example: the TCP/IP data network

The data network is used extensively throughout the world to connect individuals and organizations. Data networks can be connected together to allow users seamless access to resources that are hosted outside of the particular provider they are connected to. The Internet

Internet

The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

 is the best example of many data networks from different organizations all operating under a single address space

Address space

In computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity.- Overview :...

.

Terminals attached to TCP/IP networks are addressed using IP address

IP address

An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...

es. There are different types of IP address, but the most common is IP Version 4. Each unique address consists of 4 integers between 0 and 255, usually separated by dots when written down, e.g. 82.131.34.56.

TCP/IP are the fundamental protocols that provide the control and routing of messages across the data network. There are many different network structures that TCP/IP can be used across to efficiently route messages, for example:

• wide area network
  Wide area network
  A wide area network is a telecommunication network that covers a broad area . Business and government entities utilize WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations...
  
  s (WAN)
• metropolitan area network
  Metropolitan area network
  A metropolitan area network is a computer network that usually spans a city or a large campus. A MAN usually interconnects a number of local area networks using a high-capacity backbone technology, such as fiber-optical links, and provides up-link services to wide area networks and the...
  
  s (MAN)
• local area network
  Local area network
  A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
  
  s (LAN)
• campus area network
  Campus area network
  A campus network, campus area network, corporate area network or CAN is a computer network made up of an interconnection of local area networks within a limited geographical area...
  
  s (CAN)
• virtual private network
  Virtual private network
  A virtual private network is a network that uses primarily public telecommunication infrastructure, such as the Internet, to provide remote offices or traveling users access to a central organizational network....
  
  s (VPN)

There are three features that differentiate MANs from LANs or WANs:

1. The area of the network size is between LANs and WANs. The MAN will have a physical area between 5 and 50 km in diameter.
2. MANs do not generally belong to a single organization. The equipment that interconnects the network, the links, and the MAN itself are often owned by an association or a network provider that provides or leases the service to others.
3. A MAN is a means for sharing resources at high speeds within the network. It often provides connections to WAN networks for access to resources outside the scope of the MAN.

See also

• Active networking
  Active Networking
  Active networking is a communication pattern that allows packets flowing through a telecommunications network to dynamically modify the operation of the network.- How it works :...
  
  
• Access network
  Access network
  An access network is that part of a telecommunications network which connects subscribers to their immediate service provider. It is contrasted with the core network, which connects local providers to each other...
  
  
• Core network
  Core network
  A core network, or network core, is the central part of a telecommunication network that provides various services to customers who are connected by the access network. One of the main functions is to route telephone calls across the PSTN....
  
  
• Network analyzer
  Network analyzer
  Network analyzer may mean:* Packet analyzer, used on a computer data network* Network analyzer , a type of electronic test equipment...
  
  
• Coverage (telecommunication)
  Coverage (telecommunication)
  In telecommunications, the coverage of a radio station is the geographic area where the station can communicate. Broadcasters and telecommunications companies frequently produce coverage maps to indicate to users the station's intended service area. Coverage depends on several factors, such as...
  
  
• Double-ended synchronization
  Double-ended synchronization
  For two connected exchanges in a communications network, a double-ended synchronization is a synchronization control scheme in which the phase error signals used to control the clock at one telephone exchange are derived by comparison with the phase of the incoming digital signal and the phase of...
  
  
• Federation (information technology)
  Federation (information technology)
  A Federation is multiple computing and/or network providers agreeing upon standards of operation in a collective fashion. The term may be used when describing the inter-operation of two distinct, formally disconnected, telecommunications networks that may have different internal structures...
  
  
• MVNE
• MVNO
• Network node
• Nanoscale network
  Nanoscale network
  A nanonetwork or nanoscale network is a set of interconnected nanomachines, i.e., devices in the order of a few hundred nanometers or a few micrometers at most, which are able to perform only very simple tasks such as computing, data storing, sensing and actuation...
  
  
• Network model
  Network model
  The network model is a database model conceived as a flexible way of representing objects and their relationships. Its distinguishing feature is that the schema, viewed as a graph in which object types are nodes and relationship types are arcs, is not restricted to being a hierarchy or lattice.The...
  
  
• Optical fiber
  Optical fiber
  An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
  
  
• Submarine communications cable
  Submarine communications cable
  A submarine communications cable is a cable laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean....
  
  
• Optical mesh network
  Optical mesh network
  Optical mesh networks are a type of telecommunications network.Transport networks, the underlying optical fiber-based layer of telecommunications networks, have evolved from DCS -based mesh architectures in the 1980s, to SONET/SDH ring architectures in the 1990s...
  
  
• Telecommunications Industry Association
  Telecommunications Industry Association
  The Telecommunications Industry Association is accredited by the American National Standards Institute to develop voluntary, consensus-based industry standards for a wide variety of ICT products, and currently represents nearly 400 companies...