Download
chapter communication media n.
Skip this Video
Loading SlideShow in 5 Seconds..
CHAPTER Communication Media PowerPoint Presentation
Download Presentation
CHAPTER Communication Media

CHAPTER Communication Media

228 Vues Download Presentation
Télécharger la présentation

CHAPTER Communication Media

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. CHAPTER Communication Media

  2. Chapter Objectives • Present the functions and features of leading transmission media, both guided and open media • Guided media • Twisted pair, coaxial cable, optical fiber and mixed cabling • Open media (space) • RF, Ultraviolet, Microwave and satellite

  3. Chapter Modules • Twisted Pair • Coaxial Cable • Optical Fiber • Mixed Cabling • Wireless • Microwave • Satellite Communication

  4. MODULE Twisted Pair Wire

  5. Questions • What are the two different types of twisted pair wires that are in use? • Why are the wires twisted? • Name the categories of wires and their respective uses • What is the role played by bandwidth in the quality of the wires? • What is a Plenum wire? Where is it used? • Name the types of twisted pair wires that could be used in high speed LANs such as the Gigabit Ethernet LAN • Describe the properties of the newer categories of twisted pair wires

  6. Terminology to Remember • Shielding (Conductive material) • Insulation (Non-conductive material) • Casing (Plastic material)

  7. Types and Purpose of Twisting • Types • Unshielded twisted pair (UTP) • Shielded twisted pair (STP) • Twisting • Minimizes the effect of electromagnetic interference • The electromagnetic field from one wire counterbalances the field from the other wire

  8. Shielding and Insulation • The cables are shielded from electro magnetic interference • In both directions, from outside as well as inside • The plastic casing is not to be considered as shielding • It is an insulation against electric shock

  9. Twisted Pair Cable Illustration Source: Black Box

  10. Characteristics • Cheap • Easy to install • Generally speaking, different frequencies may not be assigned to carry different channels on the same twisted pair wire • Compared to coaxial cables, twisted pair wires have a lower bandwidth • But, recent improvements have contributed to an increase in bandwidth • Speed is proportional to bandwidth

  11. Quality and Categorization of the Wires • Twisted pair wires are categorized according to their quality • Category 3 wires are of the lower quality • Category 5, 5e, 6 etc. wires are of higher quality • Partly achieved by having a larger number of twists in the cable • Higher category wires such as Cat 6 etc. are now available

  12. Areas of Application • Phone lines • Used extensively in telecommunications • LANs

  13. Typical Twisted Pair Connection Hub/Switch Twisted Pair Wire

  14. Source: www.blackbox.com

  15. Reasons for its Increasing Popularity • Better quality UTP is being produced • Ease of installation superseding its other limitations • A LAN to be configured with twisted pair wires requires a hub • A hub based implementation is preferred because it is easy to install and manage

  16. Gigabit Ethernet Medium • IEEE 802.3ab Twisted Pair • Cat 5e (350 MHz/ 1Gbps) • IEEE 802.3z Fiber Optics

  17. LAN Speed • The following questions apply to the LAN shown in the next slide • What is the speed of the network? • How could it be upgraded to a higher speed?

  18. Source: Black Box

  19. Important Areas of Application for Twisted Pair Wires • LAN • RJ 45 • 10baseT LANs operating at 10 Mbps • 100baseTX LANs operating at 100 Mbps • 1000baseT LANs operating at 1 Gbps • 8 wires • Telephone wiring connections • RJ 11 (4 wires) • RJ 14 (6 wires)

  20. Wiring a Building or Home

  21. Questions • What are the two different types of twisted pair wires that are in use? • Why are the wires twisted? • Name the categories of wires and their respective uses • What is the role played by bandwidth in the quality of the wires • What is a Plenum wire? Where is it used? • Name the types of twisted pair wires that could be used in high speed LANs such as the Gigabit Ethernet LAN • Describe the properties of the newer categories of twisted pair wires

  22. END OF MODULE

  23. MODULE Coaxial Cable

  24. Questions • Name the two types of coaxial cables • Name different use for each type of cable • Are they shielded? • What is the difference between shielding and insulation? • Explain the current replacements for coaxial cables both at the lower and higher end of the coaxial cable

  25. Questions • List the uses for thin and thick coaxial cables • Name the types of LANs that use coaxial cables

  26. A Description of the Coaxial Cable Outer casing Insulator Shielding Copper conductor

  27. Types of Coaxial Cables • Thin coaxial • Lighter version • Thin Ethernet cable • Thick coaxial • Original version • Standard Ethernet cable

  28. Thin Coaxial Cable • Higher bandwidth than twisted pair wires • Lower bandwidth compared with the thick coaxial able • More flexible compared to thick coaxial cable • Cheaper

  29. Type of Thin Coaxial Cable Used in LAN • Standardized • 10Base2 cable • 10M bps • Ethernet • Thin coaxial cable • Bus topology

  30. Thick Coaxial Cable • Compared to thin coaxial cable • Higher bandwidth • Less maneuverable • More expensive

  31. Thick Coaxial Cables Used in Networks • Standardized • 10Base5 • 10M bps • Ethernet • Thick coaxial cable • Bus topology

  32. Overall Characteristics of the Coaxial Cables • Relatively cheap compared to fiber-optic cables • Wider bandwidth compared to twisted pair wires • Good transmission characteristics • Used in high-speed synchronous transmission • Supports broadband communication • Can be tapped for multi-drop connection

  33. A Typical Coaxial Connection Bus LAN Coaxial Cable A multi-drop connection

  34. Components Used in Connecting a Computer to a Coaxial Cable T connector Network Interface Card Thin coaxial cable Terminator

  35. An Example of the Use of Thick Coaxial Cables Switch Coaxial Cable Router Backbone Thick coaxial cable

  36. Areas of Application for Coaxial Cables • Ethernet bus LANs • Telephone trunks • Mainframe networks • Cable TVs

  37. Future of Coaxial Cables • Overall use is on the decline • LANs (Lower End) • Replaced by newer and better twisted pair wires • Telephone trunks (Higher End) • Fiber cables are replacing coaxial cables • Mainframes of yesterday or perhaps today as well • Connected to peripheral devices over larger networks built on fiber-optic cables and twisted pair wires

  38. Questions • Name the two types of coaxial cables • Name different use for each type of cable • Are they shielded? • Are they insulated? • Explain the current replacements for coaxial cables both at the lower and higher end of the coaxial cable • List the uses for thin and thick coaxial cables • Name the types of LANs that use coaxial cables

  39. END OF MODULE

  40. MODULE Fiber Cables

  41. Questions • How does light travel in a fiber cable? • Name the different types of optical transmission methods • What is the most appealing aspect of fiber cables? • What are their consequences? • What are the two different types of fiber cable connections used in practice? • What are the two different materials that could be used in the production of fiber cables? • Where are fiber cables used mostly in a LAN?

  42. Increasing Speed Fiber Optics Transmission • Light travels along the path of the fiber by bouncing around its edges • Propagation methods • Multi-mode step index • Multi-mode graded index • Single mode

  43. Characteristics • Very broad bandwidth • Higher transmission speeds are possible • Signals travel a longer distance • No Electro-magnetic field • No interference • Signals are difficult to tap • Smaller size • Multiple fiber strands can be included in a cable of very small diameter

  44. Fiber-Optic Cable Bandwidth Part Of Ultraviolet Fiber Optics Visible Part Of Infra-red ? The laser beam could also travel along a fiber optic cable

  45. Fiber Cables

  46. Usage of Fiber Optic Cables • Long distance telephone cabling (trunks) • LANs • Used in large networks as the backbone • An example is the FDDI backbone used in a number of campuses • Used for extending cable limitations applicable to networking and other computing devices

  47. A Simple Fiber LAN Source: Black Box

  48. Types and Cost • Types • Regular glass fibers • Plastic fibers • Purer the fibers the better the transmission characteristics • Cost • Fiber cables are costlier than twisted pair wires and coaxial cables • The cost has declined over a period of time • Plastic fiber cables are cheaper than glass fiber cables

  49. Fiber Usage • Network backbones • Extending distance between network connections • Connecting high speed switches

  50. Web Research • Visit the following link at Corning for a tutorial on fiber optic technology http://www.corning.com/prod_svcs/index.html • http://www.corningfiber.com/library/lib_premises.htm