High Speed Data Races Home
All of us have experienced the frustration of trying to use the Web when response time is excruciatingly slow. Depending on your access to the Internet, you may face the same frustrations at work as at home. The October 1999 issue of Scientific American featured a special report on Web access issues, entitled “High Speed Data Races Home.”
If you access the Internet over conventional (voice) telephone lines, the amount of data that can be transmitted is limited by the line frequency. Because conventional telephone lines must carry audible sound, they have a frequency limit of between 300 and 3,300 Hz. However, data transmission does not need to be audible, and it can travel at much higher bandwidth (faster speeds). This special report discussed the advantages and disadvantages of the new technologies for high-speed data transmission including cable television (through coaxial cables), Digital Subscriber Lines (DSL), fiber optic access, satellite access, and wireless access.
While the last three options are exotic and not yet widely available, cable TV and DSL access are fast becoming available in most areas. The cable TV companies are marketing coaxial cable connections through their existing coaxial infrastructure. Coaxial cable transmits data as fast as 40 mbps (megabytes per second), which is nearly 1,000 times as fast as the best audible systems. However, cable has two limitations. First, all Internet data for an entire neighborhood is transmitted on a single cable. The cable modem in your home filters out your particular data at your home based on a code assigned by the cable company. This method can pose security problems for your data because anyone who has your code can access your data. Second, the coaxial cable capacity is fixed; therefore, as more of your neighbors sign up, the response time to everyone slows down.
For businesses (and some homes) the best current choice is DSL. DSL transmits data faster by using higher frequencies over telephone lines. However, these transmissions must be routed through new broadband data switching substations. To access these substations, your modem must be located within four kilometers of it. At the substation the data is converted to optical cable and sent on the Internet Service Provider (ISP). While DSL is available in most urban areas, it is taking time for the telephone companies to install optical systems and substations.
Perhaps the greatest advantage to these technologies besides faster response time is that your Internet connection is always available-no more second lines, constant busy signals, or other problems. This transition to full-time Internet availability will allow us to use the Web for many tasks, not just research, communication, and shopping. The Internet will truly become our full-time connection to the world. As information developers, we can expect to be using the Web to deliver our information more and more in the next few years.