Networking and Digital Communication PDF

Chapter 8 Networking and Digital Communication Part 1 Topics Networking Fundamentals Network Types Network Components Networking Software Protocols Connection Types Wireless communication 2 Network Fundamentals A computer network is...

Chapter 8 Networking and Digital Communication Part 1 Topics Networking Fundamentals Network Types Network Components Networking Software Protocols Connection Types Wireless communication 2 Network Fundamentals A computer network is any system of two or more computers that are linked together.  Each computer or networked peripherals on the network is called a Node Three essential components of every computer network system:  Hardware  Software  People 3 Network Types 4 Network Types PAN (Personal Area Network)  A network used for communication between devices close to one person.  E.g. Connecting a headphone to Smartphones and tablets using wireless technologies such as Bluetooth and Wi-Fi LAN (Local Area Network)  Is a network were computers are physically close to each other.  E.g. Computer lab or Home 5 Network. Network Types MAN (Metropolitan Area Network)  Is a large network designed to provide a specific geographical area such as an entire city. WAN (Wide Area Network)  Extends over a large physical distance  The internet is the largest WAN  Each LAN site is a node on WAN 6 Bandwidth (Network Speed) Quantity of data transmitted per sec  Measured in Kilobits/sec, Mbps or Gbps Bandwidth depends on:  Transmission media: copper wire or fiber optic  1 fiber optic cable can replace 10,000 copper telephone cables  Amount of traffic on the network Measure your internet speed at home  E.g. http://www.speedtest.net/ 7 Networking Components Network Interface Card:  For each node on a network to communicate with other nodes. 8 Networking Components Routers  Hardware devices or Software programs that route messages as they travel between networks  They are used to connect two or more networks together 9 10 Networking Components: Switches/Hubs Allow any node on the network to communicate with any other node HUB SWITCH 11 Networking Models Client/server model:  One or more computers act as dedicated servers and all the remaining computers act as clients. Peer-to-peer model:  Every computer on the network is both client and server 12 Networking Software NOS (Network Operating System):  It is a system that is available on servers and handles communication and requests from multiple clients. Communication Protocols:  Is a system of rules that allow two or more entities of a communications system to transmit information.  Same protocol is required for data exchange  E.g. If one machine is “talking” at 200Kbps and the other is “listening” at 100Kbps , the message doesn’t get through 13 How does the internet work TCP/IP  The most famous protocol for computer networking  It controls the exchange of data between computers on the Internet  Example Protocols: HTTP, FTP, DHCP, DNS, etc… Information transmitted over the internet is broken into smaller pieces called packets.  E.g. An e-mail message or an image is broken into parts of a certain size 14 Making Connections Modem Connection (Dialup sound)  Transmission through Telephone lines  Conversion at both ends  Speed: up to 56.6 Kbps 15 Making Connections Broadband Connection  Greater bandwidth than modems Types  DSL: (digital subscriber line) Uses standard Tel. Lines  Cable modems: Uses fast TV cables  Satellite connection: Uses TV dishes  Optical Fiber: Sea cables 16 Wireless Networks Is a computer network that uses wireless data connections between network nodes. Examples include:  Wireless Local Area Networks  Cell Phone/Mobile Networks  Wireless Sensor Networks Wireless Technology Standards:  Wi-Fi  Wi-Max  Infrared  Bluetooth  3G, 4G, 5G 17  Wireless Connections Wi-Fi  Fastest growing Wireless technology standard  Uses radio waves to link computers to Wireless Access Point (WAP)  Allows Peer to peer communication Is affected generally by:  Objects blocking the signals  Antenna placement  Other wireless devices in the same air space Generatio Maximum n Bandwidth Wi‑Fi 6 600–9608 Mbit/s Wi‑Fi 5 433–6933 Mbit/s Wi‑Fi 4 72–600 Mbit/s 18 Wireless Connections Wi-Max  New radio based technology  A single tower can provide access to 25 square mile area 19 Wireless Connections Bluetooth:  is a wireless technology standard for exchanging data between fixed and mobile devices over short distances Designed to quickly and automatically connect devices like printers, PDAs, Cameras, etc… to computers and to each other and communicates regardless of OS. Bluetooth uses low power, low cost transmitters and receivers with a range of 10- 100 meters. Wearable computing 20 Mobile Phone Networks 21 Mobile Phone Networks Tethering:  Cabling a laptop to a mobile phone to get internet connection. Mobile Hotspot:  Tethering done over Wi-Fi, where the internet- connected mobile device is acting as a portable Wireless Access Point (WAP) 22 Securing Wireless Networks Packets of information on a wireless network are broadcast through airwaves. Anyone with sufficient technical expertise can intercept these signals and decode your messages. Measures to help secure your communication:  Setup a password for your wireless network  Use encryption and wireless security protocols WEP: Wired Equivalent Privacy (Lowest protection) WPA: Wi-Fi Protected Access (Compatible with more devices) WPA2: Wi-Fi Protected Access Version 2 (Most Secure) 23