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A telecommunications network is a group of
nodes In general, a node is a localized swelling (a "knot") or a point of intersection (a Vertex (graph theory), vertex). Node may refer to: In mathematics *Vertex (graph theory), a vertex in a mathematical graph *Node (autonomous system), behaviour fo ...

nodes
interconnected by
telecommunications link In a telecommunications network A telecommunications network is a group of nodes interconnected by links that are used to exchange messages between the nodes. The links may use a variety of technologies based on the methodologies of circuit sw ...
s that are used to exchange messages between the nodes. The links may use a variety of technologies based on the methodologies of
circuit switching Circuit switching is a method of implementing a telecommunications network A telecommunications network is a group of nodes interconnected by links that are used to exchange messages between the nodes. The links may use a variety of technologi ...
,
message switchingIn telecommunications Telecommunication is the transmission of information Information can be thought of as the resolution of uncertainty; it answers the question of "What an entity is" and thus defines both its essence and the nature of i ...
, or
packet switching In telecommunications, packet switching is a method of grouping Data (computing), data that is transmitted over a digital Telecommunications network, network into ''network packet, packets''. Packets are made of a header (computing), header and a p ...
, to pass messages and signals. Multiple nodes may cooperate to pass the message from an originating node to the destination node, via multiple network hops. For this routing function, each node in the network is assigned a
network address A network address is an identifier for a node or host on a telecommunications network A telecommunications network is a group of nodes interconnected by links that are used to exchange messages between the nodes. The links may use a variety o ...
for identification and locating it on the network. The collection of addresses in the network is called the
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 computer data storage, memory cell or other logical or physical entity. For software programs to ...
of the network. Examples of telecommunications networks include
computer network A computer network is a group of computers that use a set of common communication protocols over digital signal, digital interconnections for the purpose of sharing resources located on or provided by the Node (networking), network nodes. The ...
s, the
Internet The Internet (Capitalization of Internet, or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''network of networks'' t ...

Internet
, the public switched telephone network (PSTN), the global
Telex The telex network was a customer-to-customer switched network of teleprinters similar to a telephone network, using telegraph-grade connecting circuits for two-way text-based messages. Telex was a major method of sending written messages electr ...

Telex
network, the aeronautical
ACARS In aviation Aviation is the activities surrounding mechanical flight Flight or flying is the process by which an object (physics), object motion (physics), moves through a space without contacting any planetary surface, either within an atmo ...
network, and the wireless radio networks of cell phone telecommunication providers.


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 An overlay network is a computer network A computer network is a group of computers that use a set of common communication protocols over digital signal, digital interconnections for the purpose of sharing resources located on or provided by ...
s): * The
data planeThe data plane is the part of the software Software is a collection of Instruction (computer science), instructions and data (computing), data that tell a computer how to work. This is in contrast to Computer hardware, physical hardware, from wh ...
(also user plane, bearer plane, or forwarding plane) carries the network's users' traffic, the actual payload. * The
control planeIn network routing, the control plane is the part of the Router (computing), router architecture that is concerned with drawing the network topology, or the information in a routing table that defines what to do with incoming Network packet, packets. ...
carries control information (also known as
signaling In signal processing Signal processing is an electrical engineering subfield that focuses on analysing, modifying, and synthesizing signals such as audio signal processing, sound, image processing, images, and scientific measurements. Sig ...
). * The
management plane In computer networking A computer network is a group of computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of ope ...
carries the
operations, administration and management Operations, administration and management or operations, administration and maintenance (OA&M or OAM) are the processes, activities, tools, and standards involved with operating, administering, managing and maintaining any system. This commonly ap ...
traffic required for network management. The management plane is sometimes considered a part of the control plane.


Data networks

Data networks are used extensively throughout the world for communication between individuals and organizations. Data networks can be connected to allow users seamless access to resources that are hosted outside of the particular provider they are connected to. The
Internet The Internet (Capitalization of Internet, or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''network of networks'' t ...

Internet
is the best example of the
internetworking Internetworking is the practice of interconnecting multiple computer networks, such that any pair of Host (network), hosts in the connected networks can exchange messages irrespective of their hardware-level networking technology. The resulting sy ...
of many data networks from different organizations. Terminals attached to
IP network The Internet protocol suite is the Conceptual model (computer science), conceptual model and set of communications protocols used in the Internet and similar computer networks. It is commonly known as TCP/IP because the foundational protocols i ...
s like the Internet are addressed using
IP address An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.RFC 760, ''DOD Standard Internet Protocol'', DARPA, Information Sciences Institut ...
es. Protocols of the
Internet protocol suite The Internet protocol suite, commonly known as TCP/IP, is the set of communications protocol A communication protocol is a system of rules that allows two or more entities of a communications system 400px, Communication system A commu ...
(TCP/IP) provide the control and routing of messages across the and IP data network. There are many different network structures that IP can be used across to efficiently route messages, for example: *
Wide area network A wide area network (WAN) is a telecommunications network A telecommunications network is a group of nodes interconnected by links that are used to exchange messages between the nodes. The links may use a variety of technologies based on t ...
s (WAN) *
Metropolitan area network A metropolitan area network (MAN) is a computer network A computer network is a group of computers that use a set of common communication protocols over digital signal, digital interconnections for the purpose of sharing resources located ...
s (MAN) *
Local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
s (LAN) There are three features that differentiate MANs from LANs or WANs: # 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. # 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. # 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. Data center networks also rely highly on TCP/IP for communication across machines. They connect thousands of servers, are designed to be highly robust, provide low latency and high bandwidth. Data center network topology plays a significant role in determining the level of failure resiliency, ease of incremental expansion, communication bandwidth and latency.


Capacity and speed

In analogy to the improvements in the speed and capacity of digital computers, provided by advances in semiconductor technology and expressed in the bi-yearly doubling of transistor density, which is described empirically by
Moore's law Moore's law is the observation that Transistor count, the number of transistors in a dense integrated circuit (IC) doubles about every two years. Moore's law is an observation and Forecasting, projection of a historical trend. Rather than a phy ...
, the capacity and speed of telecommunications networks have followed similar advances, for similar reasons. In telecommunication, this is expressed in
Edholm's law Edholm's law, proposed by and named after Phil Edholm, refers to the observation that the three categories of telecommunication Telecommunication is the transmission of information Information can be thought of as the resolution of uncert ...
, proposed by and named after Phil Edholm in 2004. This empirical law holds that the
bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thro ...
of telecommunication networks doubles every 18 months, which has proven to be true since the 1970s. The trend is evident in the
Internet The Internet (Capitalization of Internet, or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''network of networks'' t ...

Internet
, cellular (mobile),
wireless Wireless communication (or just wireless, when the context allows) is the telecommunication, transfer of information between two or more points that do not use an electrical conductor as a medium by which to perform the transfer. The most common ...
and wired local area networks (LANs), and
personal area network A personal area network (PAN) is a computer network A computer network is a group of computers that use a set of common communication protocols over digital signal, digital interconnections for the purpose of sharing resources located on or p ...
s. This development is the consequence of rapid advances in the development of .


References

{{Authority control Telecommunications engineering Network architecture Telecommunications infrastructure