1. Computer Networks Chapter 7

2. 2 Overview  This chapter covers:  Common networking and communications applications  Networking concepts and terminology  Technical issues related to networks  general characteristics of data transmission  types of transmission media in use today  Communications protocols and networking standards  Types of hardware used with a computer network

3. 3 What Is a Network?  Define a network  A connected system of objects or people  What is a computer network?  A collection of computers and other hardware devices connected together so users can share hardware, software, and data, and electronically communicate

4. Understanding Computers: Today and Tomorrow, 13th Edition LAB NETWORK PRINTER SCANNER SERVERS Alejandra CJ Immanuel Rita NETWORK SERVER

5. Understanding Computers: Today and Tomorrow, 13th Edition CAMPUS NETWORK IT DEPT ADMISSIONS LIBRARY CIS LAB BUSINESS DIVISION CAMPUS POLICE Alejandra CJ Immanuel Rita NETWORK SERVER MONICA Taylor LAURIE Yudhis KEVIN

6. Understanding Computers: Today and Tomorrow, 13th Edition SOUTH BAY NETWORK BANANA REPUBLIC ECC CHRYSLER ABERCROMBIE STARBUCKSBARNES AND NOBLE 24 HOUR FITNESS NICHOLAS MONICA DANICA RITA JOES CAR REPAIR SARAH WHOLE FOODS SUSIE MANNY ANGELICA AARON ELYSE

7. Understanding Computers: Today and Tomorrow, 13th Edition WORLDWIDE NETWORK

8. Understanding Computers: Today and Tomorrow, 13th Edition Why learn about networks?  All around us  Use them all the time  Homes  Jobs  Schools  Airports  Hospitals

9. 9 PHONES, GPS, MONITORING, CONFERENCES, REMOTE CONSULTATIONS

10. 10 NETWORKED HOME

11. Understanding Computers: Today and Tomorrow, 13th Edition Network Enabled Appliances http://www.youtube.com/watch?v =WWgy1Y27QnI&feature=share& list=PLF5B83361104F301B

12. 12 SETTING UP A NETWORK  Networking hardware  Network adapter: Used to connect a computer to a network or the Internet  Also called network interface card (NIC) when in the form of an expansion card  Modem: Device that connects a computer to the Internet or to another computer (cable, DSL, etc.)  Wired/Wireless router: Connects wired/wireless devices in a network

13. 13 Network Adapters

14. 14 Networking Hardware for Connecting Devices and Networks  Repeater: Amplifies signals along a network  Range extender: Repeater for a wireless network  Wireless router: Typically connects both wired and wireless devices in a network

15. 15 Networking Hardware for Connecting Devices and Networks  Hub:  Central device that connects all of the devices on the network and sends data to all devices  Switch:  Connects devices in a network like a hub but only sends data to the device for which the data is intended  Wireless access point:  Used to grant network access to wireless client devices  Bridges:  Used to connect two networks together usually on a local network

16. Understanding Computers: Today and Tomorrow, 13th Edition Network Characteristics  Communication Architecture  Client/server and P2P  Topology  Size/Coverage Area  Transmission Characteristics  Bandwidth  Signal  Transmission Method  Data Organization  Transmission Direction  Delivery Method  Hardware  Connection method  Protocols and Standards

17. 17 Network Communication Architectures  The way networks are designed to communicate  Client-server networks  Peer-to-peer (P2P) networks: All computers at the same level

18. 18 Network Topologies  How the devices in the network (called nodes) are arranged  Star networks  Bus networks  Mesh networks  Ring networks  Tree networks

19. 19 Network Topologies

20. 20 Network Size and Coverage Area  Personal area network (PAN)  Home area network (HAN)  Local area network (LAN)  Campus area network (CAN)  Metropolitan area network (???)  Wide area network (???)  Storage area network (???)  Virtual private network (???)

21. 21 Data Transmission Characteristics  Bandwidth: The amount of data that can be transferred in a given period of time  Measured in bits per second (bps)  Analog (waves) vs. digital Signal (discrete chunks/packets)  Serial vs. parallel transmission method  Serial = 1 bit  Parallel = at least 1 byte at a time = usually 8

22. Understanding Computers: Today and Tomorrow, 13th Edition Transmission Timing Organization

23. 23 Data Transmission Characteristics  Transmission direction:  Simplex transmission  Half-duplex transmission  Full-duplex transmission

24. 24 Data Transmission Characteristics  Type of delivery method:  Circuit-switched  Packet-switched  Broadcast

25. 25 Network Connection Method  Wired  connected to the network via physical cables  Wireless networks  data is typically sent via radio waves

26. 26 Communications Protocols and Networking Standards  Protocol: A set of rules for a particular situation  Communications protocol: A set of rules that determine how devices on a network communicate  TCP/IP: The most widely used communications protocol – used with the Internet  Standard: A set of criteria or requirements approved by a recognized standards organization  Networking standards: Address how networked computers connect and communicate  Needed to ensure products can work with other products  Communications protocol: A set of rules that determine how devices on a network communicate

27. HERTZ How communications work

28. Understanding Computers: Today and Tomorrow, 13th Edition Electro-magnetic Spectrum  The range of all possible frequencies of electromagnetic radiation  Measured in Hertz (Hz)  Consists of the Electromagnetic radiation and frequency bands  Range of Hz (energy – radiation)  Spectrum controls distance, volume, ability to pass through barrier  Wireless Spectrum -  Radio Signals - Frequencies assigned by FCC

29. 29 The Electromagnetic Spectrum

30. CONNECTIONS  CELLULAR  SATELLITE  WiFi  Ethernet

32. ETHERNET A wired connection

33. 33 Ethernet (802.3)  Ethernet: Most widely used standard for wired networks  Continually evolving  Original (10Base-T) Ethernet networks run at 10 Mbps  Newer 100 Mbps, 1Gbps, and 10 Gbps versions are common  100 Gbps and Terabit Ethernet are in development  Power over Ethernet: Allows electrical power to be sent along with data on an Ethernet network  Most often used by businesses

34. 34 Power over Ethernet (PoE)

35. 35 Phoneline, Powerline, G.hn, and BPL (802.5)  Phoneline: Allows networking via ordinary telephone wiring  Powerline: Allows networking via ordinary electrical outlets  G.hn: An emerging standard for home networks creating via phone lines, power lines, and coaxial cable  Broadband over powerline (BPL): Uses existing power lines to deliver broadband internet to some homes  Limited areas

36. Wi-Fi Wireless Fidelity

37. 37 Wi-Fi (802.11)  Wi-Fi (802.11): A family of wireless networking standards using the IEEE standard 802.11  Current standard for wireless networks in homes and offices  Designed for medium-range transmission  Wi-Fi hardware built into most notebook computers and many consumer devices today  Wi-Fi hotspots are rapidly multiplying

38. 38 Wi-Fi (802.11)  Speed and distance of Wi-Fi networks depends on:  Standard and hardware being used (continually evolving)  Number of solid objects between the access point and the computer or device  Possible interference

39. 39 WiMAX and Mobile WiMAX  WiMAX (802.16): Fairly new wireless standard for longer range wireless networking connections  Designed to deliver broadband to homes, businesses, other fixed locations  Hotzones close to 2 miles (similar in concept to cell phone towers)  Mobile WiMAX: Mobile version of the standard  Broadband by via mobile phone, portable computer, etc.

40. 40 WiMAX and Mobile WiMAX

41. CELLULAR Wireless

42. 42 Cellular Standards  Cellular standards: Continually evolving  1 st generation: Analog and voice only  2 nd generation: Digital, both voice and data  3 rd generation: HSDPA/UMTS (high speed downlink, universal mobile,) EV-DO (evolution data optimized)  4 th generation: mobile WiMAX, LTE

43. 43 Short-Range Wireless Standards  Bluetooth: Very short range (less than 10 feet)  For communication between computers or mobile devices and peripheral devices  Bluetooth devices are automatically networked with each other when they are in range (piconets)

44. 44 Cellular Radio Transmissions  Cellular radio: Uses cellular towers within cells  Calls are transferred from cell tower to cell tower as the individual moves  Cell tower forwards call to the MTSO  Data works in similar manner  Cell phone transmission speed depends on the cellular standard being used

45. 45 Cellular Radio Transmissions

46. MICROWAVE & SATELLITE A wireless connection

47. 47 Microwave and Satellite Transmissions  Microwaves: High-frequency radio signals  Sent and received using microwave stations or satellites  Signals are line of sight, so microwave stations are usually built on tall buildings, towers, mountaintops  Communication satellites are launched into orbit to send and receive microwave signals from earth  Traditional satellites use geosynchronous orbit  Low earth orbit (LEO) satellites were developed to combat delay  Medium earth orbit (MEO) satellites are most often used for GPS systems

48. 48 Microwave and Satellite Transmissions

49. 49 Infrared (IR) Transmissions  IR: Sends data as infrared light  Like an infrared television remote, IR requires line of sight  Because of this limitation, many formerly IR devices (wireless mice, keyboards) now use RF technology  IR is still sometimes used to beam data between portable computers or gaming systems, or send documents from portable computers to printers