CS6204 - WWW: Beyond the Basics

Internet for the masses

by Theodoros P. David

The Challenge

Problem #1: Internet can be accessed only through a computer.

• Personal Computer vs Television

  97% of US homes own a TV

  65% of US homes do not own a PC

  
  

  Why ?

  1. PCs require technical sophistication to operate them

  2. PCs are expensive (to buy & to maintain)

Problem #2: Low Bandwidth to home users

Network Media

• Most common Internet access: Analog Modem (14.4, 28.8, 33.6 kbps)

• New Telecommunications Bill of 1996:

  Computer & Communications industries are free to

  provide their services in any telecommunication domain.

• High Bandwidth to the home through existing networks.

Internet Appliances

• Network Computer (NC)

  Oracle, Apple, IBM, Sun, Netscape

  Network PC (NetPC)

  Intel, Microsoft

  ...others (e.g. IVDS WWW Browser)

Network Computer - A family of Network Devices

• Standard Desktop NC ( picture)

  For office or home. Includes keyboard & monitor.

  NC TV

  TV Set-top box

  Internet Television

  For living room. Mostly for web access & entertainment use.

  NC Phone (picture)

  Screen phone. For email, online yellow pages, travel reservations.

Who will use the NC ?

• Corporations
  Intranets

  Home Consumers

  Web Browsing, Email, Entertainment, Simple applications.

  Education

  "A computer in every student's desk"?

  Developing Countries

  Lower cost than PCs.

How the NC works ?

• Comply with Internet Standards
  Text, Pictures, Audio, Video
  Standards are either stored on the NC or downloaded from the network as needed

  Central Processing Unit (CPU)

  Depends on the market each NC type is targeted at.

  (Pentium, 32-bit RISC down to a simple FPGA)

  Network Interface

  Currently: Analog modem, ISDN, Ethernet adapter, T1, ATM

  Future: Cable modem, ADSL modem, Fast Ethernet

  Input/Output Interface

  Supports standard PC I/O interfaces

  Infrared Remote interfaces (remote control, wireless keyboard)

  Television Viewing (High quality (S)VGA monitor -> NTSC screen)

Network Connections

Observations

• Often the bottleneck is the Last mile connection to the user.

• Home users are "consuming" much more information, than they are "producing".

  
  

• Asymmetric Network Technologies

  Huge Downstream Bandwidth
  Small Upstream Bandwidth
  Can be achieved using existing networks to the home.

Cable TV Networks

• Cover 94% of US homes

• Problem: Most are one-way (downstream). Need to be upgraded to two-way.

• Cable modems
  - Downstream bandwidth: (Shared) 500 kbps - 30 Mbps
  - Upstream bandwidth: (Shared) 96 kbps - 2 Mbps
  - Telephone return path option for one-way networks (analog modem)
  - Connected to PC/NC through Ethernet adapter (soon Fast Ethernet)

  Internet over cable (img)

  IEEE 802.14 working group committee.

Telephone networks

• Integrated Services Digital Network (ISDN)

  - Advantage: It's already in the market.
  - Symmetric 56 or 128 kbps bandwidth over one telephone line (BRI).
  - Digital "modem": almost instantaneous connection.

  Asymmetric Digital Subscriber Line (ADSL)

  - Downstream bandwidth: (Dedicated) 1.5 - 9 Mbps

  - Upstream bandwidth: (Dedicated) 16 - 640 kbps

  - 4kHz frequencies reserved for Plain Old Telephone System (POTS)

  conversations (can use telephone & Internet at the same time)

  - Sample ADSL connection

Satellite Networks

• Hardware required:
  Satellite dish
  Analog line & modem

  Downstream Bandwidth: (Shared) 400 kbps

  Upstream bandwidth: 33.6 kbps (analog modem)

  Connects to PC/NC through Ethernet adapter.

  DirectPC (shipping today)

  Sample satellite connection

Conclusions

Network Computers mirror our world and our lives.