Networks

Networks

1. LANS (Local Area Networks)

   • Pros and Cons
     • Advantages
       • Easily share files and data
       • Share resources such as printers and internet connections
       • Communicate with other network users
       • Store data centrally for ease of access and backup
     • Disadvantages
       • Computers will be more vulnerable to hackers
       • Increased risk of data corruption
       • Computers can be more easily attacked by viruses
       • Implementation costs are higher because of a server and network cabling
   • Client server netwroks
     • One or more computers are designated to serve the client computers. These clients will communicate with each other and externally through the server.
     • Server
       • A computer that includes a faster processor, more RAM and a lot more backing storage space than a client computer.
       • A file server may look after the organidation of files on the network
       • A print server may coordinate the printing on the network
     • Terminal
       • Any computer that gives a user access to any type of network 
   • Peer-to-peer networks
     • A peer to peer network allow every computer to communicate directly with every other computer in the network
   • Cabled LAN
     • Network Interface Card
       • A conputer is connected to a LAN using a NIC
     • Wireless LAN
       • Component requirements
         • Wireless access points
           • A wireless connection requirement containing a radio reciever, encryption and communications software, that broadcast to and recieve signals from wireless netnetwork interface cards
         • Wireless NICs
         • Routers
           • A harware device that enable several computers to communicate through a wireless acess point at the same time
       • Booster
         • A device that amplifies a wireless signal so that it can be detected at greater distances from the wireless access point.
       • Than a wired LAN: 》more flexible 》relatively slow transmission speed 》prone to illegal access more

2. PANs (Personal Area Networks)

   • Bluetooth
     • Short range
     • Radio signals
     • Than WiFi: 》much slower data transfer rate 》much shorter range
     • Requires a tranceiver chip

3. WANS (Wide Area Networks)

   • Bandwidth
     • The volume of data that can be transmitted in a given time
   • Narrowband
     • Refers to data transmission over a telephone line using an analogue modem
     • Uses dial-up to access the Internet
     • Modem
       • A device used to convert the digital signal emitted by a computer to analogue signals that can be transmitted over a telephone line
   • Broadband
     • Data transmission using ADSL and cable
       • ADSL: Asymmetric Digital Subscriber Line
         • A means of transmitting digital signals using telephone lines
           • Many times faster than narrownband