9.1

LEARNING OBJECTIVESLEARNING OBJECTIVES

• DESCRIBE COMPONENTS OF DESCRIBE COMPONENTS OF TELECOMMUNICATIONS SYSTEMTELECOMMUNICATIONS SYSTEM

• CALCULATE CAPACITY OF CALCULATE CAPACITY OF TELECOMMUNICATIONS CHANNELS TELECOMMUNICATIONS CHANNELS & EVALUATE TRANSMISSION MEDIA& EVALUATE TRANSMISSION MEDIA

• COMPARE TYPES OF COMPARE TYPES OF NETWORKSNETWORKS

**9.2

9.5

TELECOMMUNICATIONSTELECOMMUNICATIONS

COMMUNICATING INFORMATIONCOMMUNICATING INFORMATION

VIA ELECTRONIC MEANSVIA ELECTRONIC MEANS

OVER SOME DISTANCEOVER SOME DISTANCE

**

INFORMATION INFORMATION SUPERHIGHWAYSUPERHIGHWAY

NATIONAL / WORLDWIDENATIONAL / WORLDWIDE

HIGH SPEEDHIGH SPEED

DIGITAL TELECOMMUNICATIONSDIGITAL TELECOMMUNICATIONS

ACCESSIBLE BY GENERAL PUBLICACCESSIBLE BY GENERAL PUBLIC

• **

9.6

SYSTEM COMPONENTSSYSTEM COMPONENTS

SYSTEMSYSTEM

INPUT OUTPUTPROCESS

FEEDBACK

• COMPUTERSCOMPUTERS• TERMINALS TERMINALS (Input / Output Devices)(Input / Output Devices)• COMMUNICATIONS CHANNELSCOMMUNICATIONS CHANNELS• PROCESSORS PROCESSORS (Modems; Multiplexers; (Modems; Multiplexers;

Front-end Processors)Front-end Processors)• COMMUNICATIONSCOMMUNICATIONS SOFTWARE SOFTWARE

**

9.7

PROTOCOLPROTOCOLRULES & PROCEDURESRULES & PROCEDURES

TO GOVERN TRANSMISSIONTO GOVERN TRANSMISSION

BETWEEN COMPONENTS BETWEEN COMPONENTS

IN A NETWORKIN A NETWORK

(ALLOWS COMPONENTS(ALLOWS COMPONENTS

IN A NETWORK TO TALKIN A NETWORK TO TALK

TO EACH OTHER)TO EACH OTHER)

**

9.8

ANALOG SIGNALANALOG SIGNAL

A CONTINUOUS WAVEFORM THAT A CONTINUOUS WAVEFORM THAT PASSES THROUGH A PASSES THROUGH A COMMUNICATIONS MEDIUM; USED COMMUNICATIONS MEDIUM; USED FOR VOICE COMMUNICATIONSFOR VOICE COMMUNICATIONS

**

9.9

DIGITAL SIGNALDIGITAL SIGNAL• DISCRETE WAVEFORMDISCRETE WAVEFORM• TWO DISCRETE STATES:TWO DISCRETE STATES:– 1-BIT & 0-BIT– ON / OFF PULSE

• DATA COMMUNICATIONDATA COMMUNICATION• USES USES MODEMMODEM TO TRANSLATE ANALOG TO TRANSLATE ANALOG

TO DIGITAL, DIGITAL TO ANALOGTO DIGITAL, DIGITAL TO ANALOG

**

9.10

0010111010011101001010101110111100100010000101111010110

COMMUNICATION COMMUNICATION CHANNELSCHANNELS

MEANS BY WHICH DATA ARE MEANS BY WHICH DATA ARE TRANSMITTED:TRANSMITTED:

• TWISTED WIRESTWISTED WIRES (Copper Wires)(Copper Wires)

• COAXIAL CABLECOAXIAL CABLE (Insulated Copper (Insulated Copper Wires)Wires)

• FIBER-OPTIC CABLEFIBER-OPTIC CABLE

• WIRELESSWIRELESS

**9.11

• SUPER CLEAR GLASS STRANDSSUPER CLEAR GLASS STRANDS• FAST, LIGHT, DURABLEFAST, LIGHT, DURABLE• UP TO TEN BILLION BITS PER SECOND, UP TO TEN BILLION BITS PER SECOND,

FULL DUPLEXFULL DUPLEX• EXPENSIVE, HARDER TO INSTALLEXPENSIVE, HARDER TO INSTALL• OFTEN USED AS OFTEN USED AS BACKBONEBACKBONE OF OF

NETWORKS (MAJOR TRAFFIC)NETWORKS (MAJOR TRAFFIC)

**

FIBER OPTICSFIBER OPTICS

SIGNALSIGNAL LASERLASER CABLECABLE PHOTOPHOTODETECTORDETECTOR SIGNALSIGNAL

9.12

LOW-ORBIT SATELLITELOW-ORBIT SATELLITE

UPLINKUPLINK

MICROWAVE MICROWAVE TRANSMISSIONTRANSMISSION

DOWNLINKDOWNLINK

9.13

WIRELESS TRANSMISSION WIRELESS TRANSMISSION TECHNOLOGIESTECHNOLOGIES

• PAGING SYSTEM:PAGING SYSTEM: Small pager beeps Small pager beeps when receives short messagewhen receives short message

• CELLULAR TELEPHONE:CELLULAR TELEPHONE: Device uses Device uses radio waves to reach antennas within radio waves to reach antennas within areas called cellsareas called cells

• MOBILE DATA NETWORKS:MOBILE DATA NETWORKS: Radio - Radio - based data network using hand-held based data network using hand-held computers. cheap, efficientcomputers. cheap, efficient

**9.14

WIRELESS TRANSMISSION WIRELESS TRANSMISSION TECHNOLOGIESTECHNOLOGIES

• PERSONAL COMMUNICATION SERVICE:PERSONAL COMMUNICATION SERVICE: Cellular; lower power; higher frequency. Cellular; lower power; higher frequency. Smaller phones not shielded by buildings, Smaller phones not shielded by buildings, tunnelstunnels

• PERSONAL DIGITAL ASSISTANT:PERSONAL DIGITAL ASSISTANT: Pen Pen sized, hand-held, digital communicatorsized, hand-held, digital communicator

• SMART PHONE:SMART PHONE: Wireless, voice, text, Wireless, voice, text, InternetInternet

**9.15

COMMUNICATIONS COMMUNICATIONS CHANNELSCHANNELS

• TRANSMISSION SPEED:TRANSMISSION SPEED: Bits per Bits per Second (bps); BaudSecond (bps); Baud

• BANDWIDTH:BANDWIDTH: Capacity of Channel; Capacity of Channel; Difference between Highest & Difference between Highest & Lowest FrequenciesLowest Frequencies

**

9.16

MEDIUMMEDIUM SPEEDSPEED COSTCOST TWISTED WIRETWISTED WIRE 300 bps - 10 Mbps300 bps - 10 Mbps LOWLOW

MICROWAVEMICROWAVE 256 Kbps - 100 Mbps256 Kbps - 100 Mbps

SATELLITESATELLITE 256 Kbps - 100 Mbps256 Kbps - 100 Mbps

COAXIAL CABLECOAXIAL CABLE 56 Kbps - 200 Mbps56 Kbps - 200 Mbps

FIBER OPTICSFIBER OPTICS 500 Kbps - 10 Gbps500 Kbps - 10 Gbps HIGHHIGH bps: BITS PER SECONDbps: BITS PER SECOND Kbps: KILOBITS PER SECONDKbps: KILOBITS PER SECOND Mbps: MEGABITS PER SECONDMbps: MEGABITS PER SECOND Gbps: GIGABITS PER SECONDGbps: GIGABITS PER SECOND

SPEEDS & COST OF MEDIASPEEDS & COST OF MEDIA

9.17

NETWORK TOPOLOGIESNETWORK TOPOLOGIES

HOSTHOST

USERUSER

USERUSER

USERUSER USERUSER

STAR

9.19

NETWORK TOPOLOGIESNETWORK TOPOLOGIES

BUS

USERUSER

USERUSER

USERUSER

USERUSER

USERUSER

USERUSER

9.20

NETWORK TOPOLOGIESNETWORK TOPOLOGIES

USERUSER

USERUSER

USERUSER

USERUSER

RING

9.21

LOCAL NETWORKSLOCAL NETWORKS• PRIVATE BRANCH EXCHANGE (PBX):PRIVATE BRANCH EXCHANGE (PBX):

special-purpose computer designed for special-purpose computer designed for handling and switching office telephone handling and switching office telephone calls at a company sitecalls at a company site

• LOCAL AREA NETWORK (LAN):LOCAL AREA NETWORK (LAN): dedicated dedicated channels; limited distance (less than 2000 channels; limited distance (less than 2000 foot radius); higher capacity than PBX. foot radius); higher capacity than PBX. Can share expensive hardware & softwareCan share expensive hardware & software

9.22

LOCAL AREA NETWORK LOCAL AREA NETWORK (LAN)(LAN)• SERVER:SERVER: stores programs, data; determines access to stores programs, data; determines access to

networknetwork• GATEWAY:GATEWAY: connection to other dissimilar networksconnection to other dissimilar networks• ROUTER:ROUTER: route data through several connected LANs route data through several connected LANs

or to a WANor to a WAN• NETWORK OPERATING SYSTEM (NOS):NETWORK OPERATING SYSTEM (NOS): manages file manages file

server; routes communications on networkserver; routes communications on network• PEER - TO - PEER:PEER - TO - PEER: in some small networks all in some small networks all

computers have equal powercomputers have equal power

**

9.23

ELEMENTS OF A BASIC LANELEMENTS OF A BASIC LAN

• SERVERSERVER

• CABLINGCABLING

• NETWORK INTERFACE CARDS (NICs)NETWORK INTERFACE CARDS (NICs)

• SOFTWARE (network operating system) FOR SOFTWARE (network operating system) FOR CLIENTS, SERVERS OR PEERSCLIENTS, SERVERS OR PEERS

9.23

NETWORK SPANS LARGE GEOGRAPHIC NETWORK SPANS LARGE GEOGRAPHIC DISTANCESDISTANCES

CAN INCLUDE CABLE, SATELLITE, MICROWAVECAN INCLUDE CABLE, SATELLITE, MICROWAVE• SWITCHED LINES:SWITCHED LINES: Route Determined by Route Determined by

Current TrafficCurrent Traffic• DEDICATED LINES:DEDICATED LINES: Constantly Available for Constantly Available for

High-Volume Traffic (typically a flat rate is paid High-Volume Traffic (typically a flat rate is paid for total access to the line)for total access to the line)

**

WIDE - AREA NETWORK WIDE - AREA NETWORK (WAN)(WAN)

9.24

ORGANIZATION’S HARDWARE, ORGANIZATION’S HARDWARE, SOFTWARE, TELECOMMUNICATIONS SOFTWARE, TELECOMMUNICATIONS AND DATA RESOURCES ARE AND DATA RESOURCES ARE ARRANGED TO PUT MORE COMPUTING ARRANGED TO PUT MORE COMPUTING POWER ON THE DESKTOP AND TO POWER ON THE DESKTOP AND TO CREATE A COMPANYWIDE NETWORK CREATE A COMPANYWIDE NETWORK LINKING MANY SMALLER NETWORKSLINKING MANY SMALLER NETWORKS

**

ENTERPRISE ENTERPRISE NETWORKINGNETWORKING

9.31

INTERNETWORKINGINTERNETWORKINGLINKING OF SEPARATE NETWORKS, LINKING OF SEPARATE NETWORKS,

EACH OF WHICH RETAINS ITS OWN EACH OF WHICH RETAINS ITS OWN IDENTITY, INTO AN IDENTITY, INTO AN

INTERCONNECTED NETWORKINTERCONNECTED NETWORK

**

9.32

NETWORK A

NETWORK B

NETWORK C

CONNECTIVITYCONNECTIVITY

MEASURE OF ABILITY OF COMPUTING MEASURE OF ABILITY OF COMPUTING DEVICES TO PASS & SHARE INFORMATION DEVICES TO PASS & SHARE INFORMATION

WITHOUT HUMAN INTERVENTIONWITHOUT HUMAN INTERVENTION

OPEN SYSTEMS: Software Able to Function OPEN SYSTEMS: Software Able to Function on Different Computer Platforms. on Different Computer Platforms. Nonproprietary Operating Systems, Nonproprietary Operating Systems, Applications, Protocols (e.g. Java)Applications, Protocols (e.g. Java)

**

9.33

PROBLEMS POSED BY PROBLEMS POSED BY ENTERPRISE NETWORKINGENTERPRISE NETWORKING

• CONNECTIVITYCONNECTIVITY• LOSS OF MANAGEMENT CONTROLLOSS OF MANAGEMENT CONTROL• ORGANIZATIONAL CHANGE ORGANIZATIONAL CHANGE

REQUIREMENTSREQUIREMENTS• HIDDEN COSTS OF CLIENT/SERVER HIDDEN COSTS OF CLIENT/SERVER

COMPUTINGCOMPUTING• NETWORKNETWORK RELIABILITY & SECURITYRELIABILITY & SECURITY

**

9.40

COSTS OF CLIENT/SERVER COSTS OF CLIENT/SERVER SYSTEMSSYSTEMS

• OPERATIONS & SUPPORTOPERATIONS & SUPPORT• APPLICATION DEVELOPMENTAPPLICATION DEVELOPMENT• HARDWARE, SOFTWARE, INSTALLATION HARDWARE, SOFTWARE, INSTALLATION

AND MAINTENANCEAND MAINTENANCE• EDUCATION & EDUCATION & TRAININGTRAINING

**

9.41

SOME SOLUTIONS TO SOME SOLUTIONS TO PROBLEMSPROBLEMS

• Managing the changeManaging the change• Education and trainingEducation and training• Data administration disciplines Data administration disciplines

(accurateness, data available only to (accurateness, data available only to authorized users and properly backed up)authorized users and properly backed up)

• Planning for connectivityPlanning for connectivity

**

9.41

9.45