REMOTE ACCESS Lecture II

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REMOTE ACCESSLecture II
REMOTE ACCESS
Presented By- Dr. Fred Zellner University Of
Houston Central Computing and Telecommunication
Services
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REMOTE ACCESS

• What Is It ?
• Accessing a network from a remote location
• Accessing the LAN from a remote location
• Accessing the Internet

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REMOTE ACCESS

• WHY REMOTE ACCESS ?
• E-Mail and File Transfers
• Online transaction processing
• Emphasis on telecommuting
• Price reductions in portable systems
• Competitive Pressures

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REMOTE ACCESS

• TYPES OF REMOTE ACCESS

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REMOTE ACCESS

• REMOTE ACCESS USERS

HOME OFFICE
REMOTE ACCESS
SOHO
TRAVELLING EMPLOYEE
OUTBOUND
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REMOTE ACCESS

• FUTURE ARCHITECTURE

Data Management
SERVER
Application Logic
Remote Middleware
SATELLITE WIRELESS
WAN
ISDN ADSL MODEM CABLE MODEM
Remote Middleware
Data Management
MOBILE/ REMOTE CLIENT
Application Logic
Presentation
Source-Gartner Group
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REMOTE ACCESS

• FEATURES OF THE ARCHITECTURE
• STORE AND FORWARD
• SINGLE SESSION COMMUNICATIONS
• NETWORK INDEPENDENCE

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REMOTE ACCESS

• BANDWIDTH DEMAND FORECAST

TOTAL DESIRED BANDWIDTH - 528 Kbps
Source-Gartner Group
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REMOTE ACCESS

• OPTIMIZATION TECHNIQUES
• GENERIC TECHNIQUES
• LAN BASED TRAFFIC OPTIMIZATION
• APPLICATION DRIVEN TECHNIQUES

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REMOTE ACCESS

• GROWTH IN NUMBER OF REMOTE ACCESS USERS

No.of Users (in Millions)
SourceGartner Group
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REMOTE ACCESS

• SUMMARY TILL NOW
• More than 32m remote users by 2000.
• By 2001,Remote Access will be a necessity not a
  luxury.
• Bandwidth requirement will shoot up.
• By, 2001 new applications for Deferred Remote
  Access will be written.
• By 2001, Remote Performance Optimization
  standards
• will come in place.

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REMOTE ACCESS
MODEM TECNOLOGY
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REMOTE ACCESS
DIAL UP MODEMS

• TILL NOW.
• Older Standards
• V.32
• V.32 bis
• V.34
• V.34

33.6Kbps
V.34
28.8Kbps
V.34
14.4Kbps
V.32bis
9600bps
V.32
300bps
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REMOTE ACCESS
DIAL UP MODEMS

• WHAT NOW.
• Kflex 56.(Motorola)
• X 2(3Com)

56 Kbps
Kflex 56 X2
33.4 Kbps
V.34
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REMOTE ACCESS

• THE 56K TECHNOLOGY

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REMOTE ACCESS

• FEATURES OF THE 56K TECHNOLOGY
• SERVICES OVER REGULAR PHONE LINES.
• 100 DIGITAL NETWORK EXCEPT THE LOCAL LOOP.
• DOWNLOADS FROM INTERNET,CORPORATE NETWORKS AT
  56Kbps.
• BACKWARD COMPATIBLE.

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REMOTE ACCESS
DIFFERENCE BETWEEN 56K AND V.34 TECHNOLOGY

• 100 DIGITAL CONNECTION EXCEPT THE LOCAL LOOP.
• ASYMMETRICAL CONNECTION.
• UPSTREAM SPEED LIMITED DUE TO A/D CONVERSION.
• USE PAM IN DOWNSTREAM AND QAM IN UPSTREAM.

• OPTIMIZED FOR END TO END ANALOG CONNECTIONS.
• SYMMETRICAL CONNECTION.
• A/D CONVERSION TAKING PLACE AT BOTH ENDS HENCE
  LIMITING SPEED.
• USES QAM IN BOTH DIRECTIONS.

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REMOTE ACCESS

• 56K DIAL UP MODEM REQUIREMENTS
• DIGITAL AT ONE END.
• 56K TECHNOLOGY SUPPORT AT BOTH ENDS.
• ONE ANALOG TO DIGITAL CONVERSION.

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REMOTE ACCESS
THE 56K MODEM TECHNOLOGY SUPPLIERS

• DEVELOPED BY ROCKWELL AND LUCENT.

• DEVELOPED BY US ROBOTICS AND 3COM.

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REMOTE ACCESS

• DISADVANTAGES OF 56K MODEMS
• USEFUL ONLY FOR INTERNET DOWNLOADS.
• NO STANDARDIZATION FROM ITU-IT.
• NO VIDEOCONFERENCING AND MULTIMEDIA APPLICATIONS
  POSSIBLE.

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REMOTE ACCESS
CABLE MODEMS
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REMOTE ACCESS

• WHAT IS CABLE MODEM TECHNOLOGY ?
• HIGH SPEED DATA TRANSFER VIA THE BROADBAND CABLE
  TV NETWORK.

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REMOTE ACCESS

• TYPICAL SCENARIO..

COAXIAL CABLE
TWISTED PAIR
SERIAL CABLE
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REMOTE ACCESS

• WITH CABLE MODEM TECHNOLOGY.

COAXIAL CABLE
TWISTED PAIR
CABLE MODEM
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REMOTE ACCESS

• WHAT IS A CABLE MODEM ?
• ACTS AS A BRIDGE, SPANNING THE CABLE MEDIAS
  ACCESS PROTOCOL AND THE PCS COMMUNICATION
  PROTOCOL.
• OPERATES AT LAYER 1 AND LAYER 2.
• HAS CONNECTORS FOR POWER,VIDEO F AND ETHERNET
  CONNECTOR.

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REMOTE ACCESS

• CABLE TV PRIMER
• COAXIAL CABLES-330Mhz or 450MHz.
• DOWNSTREAM VIDEO-50Mhz-750Mhz.
• UPSTREAM VIDEO-5Mhz-42Mhz.
• STANDARD TV CHANNEL OCCUPIES 6Mhz.
• TRADITIONAL TV SYSTEM-60 CHANNELS.

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REMOTE ACCESS

• BANDWIDTH ALLOCATION .

DOWNSTREAM
750Mhz
UPSTREAM
50Mhz
42Mhz
5Mhz
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REMOTE ACCESS

• CABLE MODEM SPEEDS

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REMOTE ACCESS
CABLE MODEM SPEEDS
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REMOTE ACCESS

• SERVICES PROVIDED BY CABLE MODEMS
• INTERNET ACCESS
• ELECTRONIC MAIL
• REMOTE ACCESS TO CORPORATE LAN.
• Contd.

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REMOTE ACCESS

• SERVICES
• INTEGRATED COMPUTER/TV ACCESS.
• BANK AT HOME SERVICES.
• HOME ENTERTAINMENT.

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REMOTE ACCESS
CABLE NETWORK
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REMOTE ACCESS

• CABLE MODEM NETWORK-AN EXAMPLE

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REMOTE ACCESS

• EXPLANATION.
• SuperHeadend-Heart of the System
• LCp-Personal Cable Modem
• LCw-Workgroup Cable Modem.
• LCb-Multiuser Cable Modem.

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REMOTE ACCESS

• CABLE MODEMS--AVERAGE COST

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REMOTE ACCESS
BANDWIDTH COST COMPARISON
/Kbps
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REMOTE ACCESS
1. Time Warner Cable 29,000 2. MediaOne
17,000 14,000 3. Cox Communications
16,000 4. Rogers Cablesystems 14,000
5. Comcast 5,800 6. Videotron
5,000 7. Shaw Communications 4,500 8.
COGECO 4,000 9. Tele-Communications Inc.
2,400 10. Adelphia 2,000 11. Cablevision
Systems 1,400 12. Jones Intercable
4,000 Other 4,000 TOTAL 111,100
CABLE MODEM SALES
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REMOTE ACCESS
CABLE MODEM--SUBSCRIBER PROJECTIONS
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REMOTE ACCESS
CABLE MODEMS--UNIT SALES PROJECTIONS
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REMOTE ACCESS

• DISADVANTAGES OF CABLE MODEMS
• HUGE INVESTMENT BY MSO.
• RELIABLE MANAGEMENT SYSTEM REQUIRED.
• NO INTEROPERABILITY BETWEEN DIFFERENT MODEMS.
• UPSTREAM SPEEDS NOT STANDARDIZED.

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REMOTE ACCESS

• PRESENT SCENARIO
• NO STANDARDS.
• PRESENT CUSTOMERS ARE MSOs.
• NO SUPPLIERS TO PROVIDE END TO END SOLUTIONS.

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REMOTE ACCESS

• CABLE MODEMS--FUTURE
• STANDARDIZATION FOR DOWNSTREAM AND UPSTREAM
  SPEEDS.
• INTEROPERABILITY BETWEEN DIFFERENT MODEMS.
• REDUCTION IN COSTS.
• CUSTOMERS WILL BE END USERS.
• SUPPLIERS WITH END TO END SOLUTIONS.

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REMOTE ACCESS
ASYNCHRONOUS DIGITAL SUSCRIBER LINE
HIT THE HIGHWAY WITHOUT LEAVING HOME
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REMOTE ACCESS

• WHAT IS ADSL ?
• ASYNCHRONOUS DIGITAL SUBSCRIBER LINE--- A NEW
  MODEM TECHNOLOGY.

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REMOTE ACCESS

• ADSL FEATURES
• HIGH SPEED NETWORK ACCESSIBILITY.
• HIGH SPEED REMOTE ACCESS.
• VIDEO ON DEMAND.
• CONSTANT CONNECTIVITY.
• NO NEED TO ADD NEW PHONE LINES.

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REMOTE ACCESS
ADSL - THE NETWORK
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REMOTE ACCESS
ADSL.SPEEDS

• ADSL MODEMS CONSISTENT WITH EUROPEAN AND NORTH
  AMERICAN DIGITAL HIERARCHIES.
• VARIABLE DATA RATES.

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REMOTE ACCESS

• TECHNOLOGY DESCRIPTIONRequirements
• FULL USE OF COPPER LINE FREQUENCY
  SPECTRUM(1.1Mhz).
• ADVANCED CODING/DECODING METHOD.
• ABILITY TO WORK WITH POTS ON SAME COPPER LINE.
• AN EFFICIENT ERROR CORRECTION CODE.

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REMOTE ACCESS

• TECHNOLOGIES USED BY ADSL
• CODING--DMT OR CAP
• CODE AND ERROR CORRECTION
• FRAMING AND SCRAMBLING

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REMOTE ACCESS
ADSL--BANDWIDTH ALLOCATION
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REMOTE ACCESS
ADSL--CODING SCHEMES
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REMOTE ACCESS
ADSL--DMT CODING TECHNIQUE
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REMOTE ACCESS

• ADVANTAGES OF DMT
• BETTER PERFORMANCE
• BIT RATE FLEXIBILITY
• RESISTANCE TO IMPULSE NOISE
• ATM SUPPORT

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REMOTE ACCESS
ADSL--DISTANCE LIMITATIONS
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REMOTE ACCESS
ADSL PRODUCTS FROM COMPANIES
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REMOTE ACCESS

• ADSL -- WHAT IS NEEDED ?

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REMOTE ACCESS

• ADSL PROVIDER IN HOUSTON
• SOUTH WESTERN BELL
• TEST SITE-SHELL

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REMOTE ACCESS
DIFFERENT xDSL
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REMOTE ACCESS

• ADSL -ISSUES TO BE RESOLVED
• HIGH SPEED xDSL,WHICH ONE?
• LAYER 1 CAP vs DMT
• LAYER 2 ATM vs ETHERNET
• LAYER 3 PPP OR NOT?

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REMOTE ACCESS
GSM
GLOBAL SYSTEM FOR MOBILE
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REMOTE ACCESS
OVERVIEW OF THE CELLULAR SYSTEM
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REMOTE ACCESS

• OVERVIEW OF CELLULAR CONCEPT
• HEXAGON GEOMETRY
• EACH CELL HAS TRANSMITTER
• FREQUENCY REUSE
• HANDOFF

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REMOTE ACCESS

• WHAT IS GSM ?
• A Second Generation Cellular System.
• First Digital Cellular System.
• Supports mobile communications in the 900Mhz and
  1.8Ghz range.

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REMOTE ACCESS

• GSM-SERVICES AVAILABLE NOW
• TELESERVICES.
• DATA SERVICESPacket Switched Data at
  300bps-9.6Kbps.
• ISDN SERVICES.

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REMOTE ACCESS

• GSM FUTURE

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REMOTE ACCESS

• GSM-HSCSD
• High Speed Circuit Switched Data.
• Will boost user Capacity to 64Kbps.
• Designed for existing Infrastructure.

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REMOTE ACCESS

• GSM-GPRS
• General Packet Radio Service
• Suitable for Bursty nature data transmission.
• Ideal for e-mail and Database access.
• Cost effective.
• Connectivity at 64Kbps.

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REMOTE ACCESS
SATELLITE / WIRELESS
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REMOTE ACCESS
SATELLITE BASICS
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REMOTE ACCESS
SATELLITE COMMUNICATION BANDS
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REMOTE ACCESS
Ka BAND SATELLITE PROJECTS
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REMOTE ACCESS

• IRIDIUM LEO SATELLITE SYSTEM
• Motorolas Global Mobile Satellite Project.
• Communication System for Voice,Data Fax and
  Paging.
• 66 LEO Satellites.
• Multiple Access Scheme-FDMA/TDMA.
• Frequency Band-Ka Band(19.4-19.6Ghz for
  Downloads)
• Ka
  Band(29.1-29.3Ghz for uplinks)
• L-Band(161Mhz)
• Year of Operation-1998

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REMOTE ACCESS
IRIDIUM SATELLITE SYSTEM
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REMOTE ACCESS
THE TELEDESIC NETWORK
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REMOTE ACCESS

• TELEDESIC NETWORK-FEATURES
• Broadband Network of LEO Satellites.
• 288 LEO Satellites.
• Frequency Band--Ka
• Uplink Frequency-18.8Ghz-19.3Ghz
• DownLink Frequency-28.6Ghz-29.1Ghz
• Contd..

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REMOTE ACCESS

• TELEDESIC...
• SPEEDS-UPLINK-2Mbps
• Downlink-640Kbps
• Uses fast Packet Switching.
• Bandwidth on demand.
• Multiple access technique-TDMA
• High Mask Angle-40

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REMOTE ACCESS

• THE HUGHES GEO NETWORK
• Broadband Satellite Network using GEO.
• 8 GEO Satellites.
• Frequency Band-Ka(17.7Ghz-30Ghz).
• Uplink Speeds-6Mbps.
• Intersatellite Links
• Interoperability with terrestrial networks.

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REMOTE ACCESS

• THE HUGHES NETWORK
• Bandwidth On Demand.
• Uses Spot Beam Technology.
• Service Begins in 2001.

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REMOTE ACCESS
THE SPOT BEAM TECHNOLOGY
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REMOTE ACCESS
BANDWIDTH ON DEMAND
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REMOTE ACCESS

• VSAT
• Stands For Very Small Aperture Terminal.
• Satellite driven Service.
• Network consists of Hubs,Outdoor Units.

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REMOTE ACCESS
VSAT NETWORK
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REMOTE ACCESS
VSAT-CONFIGURATION
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REMOTE ACCESS

• REMOTE ACCESS-FUTURE

U.S Consumer Internet Access in 2002--Main Access
Method
Source-Gartner Group
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REMOTE ACCESS
REMOTE ACCESS-FUTURE
U.S Enterprise Remote Access in 2002-Main Access
Method
Source-Gartner Group
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REMOTE ACCESS
REMOTE ACCESS WORKPLACE OF THE FUTURE
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REMOTE ACCESS
BASICS -GEOSTATIONARY SATELLITE
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REMOTE ACCESS
SATELLITE COMMUNICATION BANDS