The Net connections can be based on wire-line and wireless access technolgies.
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Usually several kinds of network connections are employed at once. Generally speaking, when an E-mail message is sent it travels from the user's computer via copper wires or coaxial cables
Satellite communication
Although facing competition from fiber-optic cables as cost-effective solutions for broadband data transmission services, the space industry is gaining increasing importance in global communications. As computing, telephony, and audiovisual technologies converge, new wireless technologies are rapidly deployed occupying an increasing market share and accelerating the construction of high-speed networks.
Privatization of satellite communication
Until recently transnational satellite communication was provided exclusively by intergovernmental organizations as
Scheduled privatization of intergovernmental satellite consortia:
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When Intelsat began to accumulate losses because of management failures and the increasing market share of fiber-optic cables, this organizational scheme came under attack. Lead by the USA, the Western industrialized countries successfully pressed for the privatization of all satellite consortia they are members of and for competition by private carriers.
As of February 2000, there are 2680 satellites in service. Within the next four years a few hundred will be added by the new private satellite systems. Most of these systems will be so-called Low Earth Orbit satellite systems, which are capable of providing global mobile data services on a high-speed level at low cost.
Because of such technological improvements and increasing competition, experts expect satellite-based broadband communication to be as common, cheap, and ubiquitous as satellite TV today within the next five or ten years.
Major satellite communication projects
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Source: Analysys Satellite Communications Database
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On the Internet, when you want to retrieve a document from another computer, you request a service from this computer. Your computer is the client, the computer on which the information you want to access is stored, is called the
A common set of standards allows the exchange of data and commands independent from locations, time, and operating systems through the Internet. These standards are called communication protocols, or the Internet Protocol Suite, and are implemented in Internet software. Sometimes the Internet Protocol Suite is erroneously identified with
Any information to be transferred is broken down into pieces, so-called packets, and the Internet Protocol figures out how the data is supposed to get from A to B by passing through routers.
Each packet is "pushed" from router to router via
The technique of breaking down all messages and requests into packets has the advantage that a large data bundle (e.g. videos) sent by a single user cannot block a whole network, because the
One of the Internet's (and of the Matrix's) beginnings was the
Routing around depends on the location of the interruption and on the availability of intersecting points between networks. If, for example, an E-mail message is sent from Brussels to Athens and in Germany a channel is down, it will not affect access very much, the message will be routed around this damage, as long as a major Internet exchange is not affected. However, if access depends on a single backbone connection to the Internet and this connection is cut off, there is no way to route around.
In most parts of the world the Internet is therefore vulnerable to disruption. "The idea of the Internet as a highly distributed, redundant global communications system is a myth. Virtually all communications between countries take place through a very small number of bottlenecks, and the available bandwidth isn't that great," says Douglas Barnes. These bottlenecks are the network connections to neighboring countries. Many countries rely on a one single connection to the Net, and in some places, such as the Suez Canal, there is a concentration of fiber-optic cables of critical importance.
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The German contribution to the Western defence system, apart from playing host and contributing to the continued presence of allied troops on its soil, takes the form of its combined arm of defence known as the Federal Armed Forces (Bundeswehr). Constituting the largest contingent of NATO troops in Europe, the armed forces are divided into an army, navy, and air force. From its inception it was envisioned as a "citizens' " defence force, decisively under civilian control through the Bundestag, and its officers and soldiers trained to be mindful of the role of the military in a democracy. Conscription for males is universal, the military liability beginning at 18 and ending at 45 years of age.
The Enigma Encryption Machine was famous for its insecurities as for the security that it gave to German ciphers. It was broken, first by the Poles in the 1930s, then by the British in World War II.