itc(data com)

• A German mathematician and physicist who made significant contributions to many fields in mathematics and sciences.

  Johann Carl Friedrich Gauss (1777 - 1855)
• Generally regarded as one of the greatest mathematicians of all time for his contributions to number theory, geometry, probability theory, geodesy, planetary astronomy, the theory of functions, and potential theory (including electromagnetism).

  Johann Carl Friedrich Gauss
• Morse also developed the Morse code which used dots and dashes to represent information
• was an American painter and inventor. After having established his reputation as a portrait painter, in his middle age Morse contributed to the invention of a single-wire telegraph system based on European telegraphs.

  Samuel Finley Breese Morse
• Samuel Morse invented the telegraph
• telegraph , the first successful data communication system that used binary coded electrical signals to transmit information.
• Johann Carl Friedrich Gauss developed a system based on a 5X5 matrix representing 25 letters so message could be sent in a single wire
• Alexander Graham Bell invented the telephone
• was a Scottish-born American inventor, scientist, and engineer who is credited with inventing and patenting the first practical telephone. He also founded the American Telephone and Telegraph Company in 1885

  Alexander Graham Bell
• Italian inventor and radio pioneer 1st Marquis of Marconi was an Italian inventor, and electrical engineer, known for his pioneering work on long distance radio transmission, development of Marconi's law, and a radio telegraph system.

  Guglielmo Marconi
• 1957, Launch of Sputnik 1- the Earth’s first artificial satellite
• 1963 - Launch of the world’s first telecommunication satellite, Syncom-1, in geosynchronous orbit.
• Syncom-2 – was an experimental communications satellite placed over the Atlantic Ocean and Brazil
• Syncom-3 –experimental geosynchronous communications satellite placed over the equator at 180 degrees longitude in the Pacific Ocean. The satellite provided live television coverage of the 1964 Olympic games in Tokyo, Japan and conducted various communications tests.
• Diwata-1- also known as PHL Microsat-1 was a Philippine microsatellite launched to the International Space Station on March 23, 2016.
• It was the first Philippine microsatellite and the first satellite built and designed by Filipinos

  Diwata-1
• Computer network - two or more computers interconnected with one another for the purpose of sharing resources such as database, backup device, and others.
• The elements of a computer network are:

  • Protocols – rules and agreements on how the different parts of the network will operate. A protocol stack is a list or set of protocols used by a system.
  • Data and Messages –information used or transmitted / received in the network.
  • Communications medium – interconnects the different devices in the network .Ex. copper and fiber optic cables
  • Devices - includes computers, routers, switches, hubs, bridges and others.
• Classification of Computer Networks according to Geographic Scope are

  • Personal Area Network (PAN)
  • local Area Network
  • Metropolitan Area Network
  • Wide Area Network
  • Global Area Network
• Classification of Computer Networks according to Geographic Scope:

  a Local Area Network are Computers confined to one building or cluster of buildings ,Relatively high speed of transmission, Usually privately owned.
• Classification of Computer Networks according to Geographic Scope:

  Metropolitan Area Network- Computers located within a city or cluster of cities, Usually use facilities of telecom or network service provider.
• Classification of Computer Networks according to Geographic Scope:

  Wide Area Network- Computers located outside a building or cluster of buildings. Computers may be located between two or more cities, or between two or more countries.
• Classification of Computer Networks according to Geographic Scope:

  Global Area Network- Computers located in different countries around the world. Ex. Internet
• Network model

  • Server - a computer or system that provides resources, data, services, or programs to other computers, known as clients, over a network
  • Client – makes the request to the server
• Two Basic Network model

  Peer to peer – all computers share their resources with all the other computers in the network.

  Dedicated client / server – one or more computers are assigned as a server and the rest of the computers are clients.
• what type of network model is this?

  peer to peer

  
• what type of network model is this?

  client server

  
• Network Topology refers to the appearance or the way a network is laid out.
• Network topology could be:

  • Physical Topology - refers to the physical lay out (geometric representation) of the computers in a network.
  • Logical Topology – Describes how data actually flow through the network. It refers to the logical layout of the computers in a network (how computers access other computers in the network)
• Most Basic topologies

  Point to point - two stations are connected

  Multipoint – connects three or more stations (Ex.: star, bus, ring, mesh and hybrid).
• Physical Mesh Topology - Every station has a direct two point communication to every other station.  Also called fully connected.

  
• Physical Star Topology- Stations are connected directly to a centrally located device such as a computer or hub which acts like a multipoint connector. The central node is sometimes called central control, star coupler, or central switch.

  
• Physical Bus Topology- All stations are connected to a single transmission medium, which allows all stations to receive transmitted packets.

  
• Physical Ring Topology- All stations are connected in tandem (series) to form a closed loop or circle.

  
• Physical Tree Topology- A central ‘root’ node (top level of the hierarchy) is connected to one or more other nodes that are one level lower in the hierarchy with a point-to point physical link.

  
• Hybrid topology- It combines two or more of the traditional topologies to form a larger, more complex topology.