1 Pertemuan 4 Networking Fundamentals Matakuliah: M0284/Teknologi & Infrastruktur E-Business Tahun: 2005 Versi: >

2 Learning Objectives Identify Different Communication Media Describe digital transmission services

3 Overview Communication Media Telephone networks Digital Transmission Services

4 Transmission Media Through which signals flow Four characteristics –Cost –Transmission capacity –Length of media before regeneration –Protection against interference

5 Media Twisted Pair Copper Wire Twisted pair copper wiring Used in telephone lines connecting our homes –low capacity 3kilobits/second Used in local area networks. –Cat 5 cables up to 100 million bits/second Low cost, low capacity, frequent regeneration and subject to interference

6 Media Copper wire

7 Media Coaxial Cable Coaxial Cable Used in local area networks and in cable television transmission Used for high speed Internet connection provided by cable t.v. companies Medium cost, 100 million bits per second, moderate protection against second

8 Media Coaxial

9 Media Fiber Optic Fiber Optic Laser lights on and off and in different colors High as 10 gigabits per second Immune to electrical interference High cost

10 Media Fiber Optic

11 Media Wireless Two configurations Directional –direct broadcast satellite, Microwave transmission: Satellite and terrestrial Omni-directional –AM,FM TV broadcast, Cellular phone

12 Media Satellite Geo-synchronous orbit Low earth orbit within 1000 miles from Earth. Few hundred satellites to cover the planet. Iridium, Teledisc, Globalstar Medium Earth orbit within 6000 miles from Earth. More than 10 satellites to cover the planet

13 Media Satellites (GEO)

14 Satellite Point-to-Point

15 Satellite VSAT Very small aperture terminal is popular for business applications

16 Telephone Network

17 Telephone Network A hierarchical network system Connection from home to Central Office –CO: Level 5 switch. Usually with low capacity copper wires Level 4 switch (toll office) –Calls that are billed pass through a toll office. Lines from here on are high capacity fiber optics Level 3 switch (primary center) Level 2 switch (sectional center) Level 1 switch (regional center)

18 Networks: Switched and Packet Telephone network is switched specific connection between two ends maintained throughout the conversation. Uses PCM to translate analog signals to digital. Uses TDM and FDM to multiplex signals over trunk lines Packet Switching Signals travel as independent packets as in US mail. Different packets (like cars) share the same line. No specific connection maintained between 2 ends. Basis of Internet and World Wide Web system

19 Telephone: Digital Transmission T-1 Carrier system SONET/ OC (Synchronous optical network/ optical carrier system) ISDN (Integrated services digital network)

20 Digital Transmission: T series Developed to send digital signals over old copper wires. A hierarchy of signals T-1 is mbps. Connect offices to Central Offices with high capacity lines T-3 lines carry 28 T-1 lines mbps

21 Digital Transmission T-1