Acessing the Internet The Net connections can be based on wire-line and wireless access technolgies. Wire-line access Wire-less access copper wires Satellites coaxial cables mobile terrestrial antennas electric power lines fixed terrestrial antennas fiber-optic cables 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 ISDN lines, etc., to an Internet Service Provider, from there, via fibre-optic cables, to the nearest Internet exchange, and on into a backbone network, tunneling across the continent und diving through submarine fibre-optic cables across the Atlantic to another Internet exchange, from there, via another backbone network and across another regional network to the Internet Service Provider of the supposed message recipient, from there via cables and wires of different bandwidth arriving at its destination, a workstation permanently connected to the Internet. Finally a sound or flashing icon informs your virtual neighbor that a new message has arrived. 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 Intelsat, Intersputnik and Inmarsat. Scheduled privatization of intergovernmental satellite consortia: Satellite consortia Year of foundation Members Scheduled date for privatization Intelsat 1964 200 nations under the leadership of the USA 2001 Intersputnik 1971 23 nations under the leadership of Russia ? Inmarsat 1979 158 nations (all members of the International Maritime Organization) privatized since 1999 Eutelsat 1985 Nearly 50 European nations 2001 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 Project name Main investors Expected cost Number of satellites Date of service start-up Astrolink Lockheed Martin, TRW, Telespazio, Liberty Media Group US$ 3.6 billion 9 2003 Globalstar 13 investors including Loral Space & Communications, Qualcomm, Hyundai, Alcatel, France Telecom, China Telecom, Daimler Benz and Vodafone/Airtouch US$ 3.26 billion 48 1998 ICO 57 investors including British Telecom, Deutsche Telecom, Inmarsat, TRW and Telefonica US$ 4.5 billion 10 2001 Skybridge 9 investors including Alcatel Space, Loral Space & Communications, Toshiba, Mitsubishi and Sharp US$ 6.7 billion 80 2002 Teledesic Bill Gates, Craig McCaw, Prince Alwaleed Bin Talal Bin Abdul Aziz Alsaud, Abu Dhabi Investment Company US$ 9 billion 288 2004 Source: Analysys Satellite Communications Database

TEXTBLOCK 1/1 // URL: http://world-information.org/wio/infostructure/100437611791/100438659839

AT&T Labs-Research The research and development division of AT&T. Inventions made at AT&T Labs-Research include so important ones as stereo recording, the transistor and the communications satellite. http://www.research.att.com/

INDEXCARD, 1/4

RIPE The RIPE Network Coordination Centre (RIPE NCC) is one of three Regional Internet Registries (RIR), which exist in the world today, providing allocation and registration services which support the operation of the Internet globally, mainly the allocation of IP address space for Europe. http://www.ripe.net

INDEXCARD, 2/4

Proxy Servers A proxy server is a server that acts as an intermediary between a workstation user and the Internet so that security, administrative control, and caching service can be ensured. A proxy server receives a request for an Internet service (such as a Web page request) from a user. If it passes filtering requirements, the proxy server, assuming it is also a cache server, looks in its local cache of previously downloaded Web pages. If it finds the page, it returns it to the user without needing to forward the request to the Internet. If the page is not in the cache, the proxy server, acting as a client on behalf of the user, uses one of its own IP addresses to request the page from the server out on the Internet. When the page is returned, the proxy server relates it to the original request and forwards it on to the user. Source: Whatis.com

INDEXCARD, 3/4

National Laboratory for Applied Network Research NLANR, initially a collaboration among supercomputer sites supported by the National Science Foundation, was created in 1995 to provide technical and engineering support and overall coordination of the high-speed connections at these five supercomputer centers. Today NLANR offers support and services to institutions that are qualified to use high performance network service providers - such as Internet 2 and Next Generation Internet. http://www.nlanr.net

INDEXCARD, 4/4