The High Speed Cable Modem
Cable television systems currently provide a high
capacity, high speed broadband connection to homes,
schools, and businesses through coaxial cable and fiber
optic networks. The addition of cable modem
technology enables customers to access a wide range of
multimedia content including graphics, audio, and video
from all over the world at high rates of speed.
The cable television industry is branching out from its
traditional role as an entertainment service industry into
a high speed data service industry. Cable television
systems were originally designed as one-way, analog
transmission systems utilizing coaxial cable. However, to
support the recent growth in demand for Internet access
and other two-way services, many cable companies are in
the midst of upgrading their existing coaxial cable
systems with fiber optic technology. These hybrid
fiber-coaxial, or HFC, networks allow cable systems to
provide reliable existing cable television services, as
well as new services such as high speed data delivery and
continuous, high speed access to the Internet.
High Speed Cable Modems: Applications for Home, School
and Business
Cable modems open the door for customers to enjoy a
wide range of high-speed data services, all at speeds
hundreds of times faster than traditional telephone
modems. Subscribers will be fully connected, 24 hours a
day, to services without interfering with their existing
cable television or telephone service. Among the services
supported by cable modem technology are:
Advanced High Speed Internet Access Service
The Cable industry's broadband network is uniquely
suited to accessing the vast amounts of information
available on the Internet. Cable's network infrastructure
can currently carry data over 1,000 times faster than the
telephone companies' twisted pair copper lines and 100
times faster than ISDN (integrated services digital
network) telephone lines. Access to the Internet and
information service providers over cable lines provides
customers with two primary benefits: speed and freedom.
The higher bandwidth of cable's fiber-coax lines
provides faster data transmission speeds than traditional
telephone lines, and since access is provided over
existing coaxial connections to customers' homes, the
cable connection does not interfere with normal telephone
activity.
Comparative Data Transmission Speeds
| Time to Transmit a Single 1 Mb Graphic Image (such as a high resolution color photograph) | |
| Telephone Modem 28.8 kbps | Approximately 5 minutes |
| ISDN 64kbps | Approximately 2 minutes |
| Cable Modem 10 Mbps | Approximately 1 second |
| Time to Transmit a 5 Mb Audio/Video Clip (Approximately 1.5 minutes) | |
| Telephone Modem 28.8 kbps | Approximately 22 minutes |
| ISDN 64 kbps | Approximately 10 minutes |
| Cable Modem 10 Mbps | Approximately 4 seconds |
| kbps = kilobits per second Mbps = megabits per second |
The Benefits of High Speed Cable Modems:
Free Time as Well as Real-Time Interactivity
The speed of cable modems offers cable customers an
advantage no other industry can provide: 24 hour
instantaneous access to the Internet. Cable companies
across the country have begun to introduce high speed
modems to their customers. With a simple installation,
customers receive high speed access to the Internet, as
well as other online services developed exclusively by
cable companies which provide additional content of local
and national interest.
Examples of these new services include @ Home, a joint
venture of TCI, Cox Communications, Comcast and Kleiner,
Perkins Caulfield and Byers; Time Warner's Road Runner;
Continental Cablevision's Highway 1; and Cablevision
Systems' Optimum Online. Cable modem technology will
provide customers with real-time access to full motion
video, audio, and data services, optimizing their time
on-line and enhancing both their usefulness and
enjoyment.
Cable modems are being manufactured by a large number
of companies, including Com21, General Instruments, Hayes
Microcomputer, Hewlett-Packard, LAN City, Motorola and
Toshiba.