sure of the number of data bits (digital 0's and 1's) transmitted each second in a communications channel. Synchronous and Asynchronous data transfer are two methods of sending data over the telephone line. In synchronous data transmission, data is sent via a bit stream, which sends a group characters in a single stream. In order to do this, modems gather groups of characters into a buffer, where they are prepared to be sent as such a stream. In order for the stream to be sent, synchronous modems must be in perfect synchronization with each other. When the clocks of each modem are in synchronization, the data stream is sent. In asynchronous transmission, data is coded into a series of pulses, including a start bit and a stop bit. A start bit is sent by the sending modem to inform the receiving modem that a character is to be sent. The character is then sent, followed by a stop bit designating that the transfer of a bit is complete.There are about 16,000 bits in a full page of English text. In order to view a full motion full screen video it would require approximately 10,000,000 bits per second, depending on the data compression. In some cases, the PC equipped with a 28.8kbps modem would be faster than a 33.6kbps or even a 56k modem, especially with sites that do not have a great deal of graphics. There are several factors in determining the time it takes to connect and display a Web site. These include the speed of your computer, your connection to your Internet service provider (ISP), your ISP’s connection to the Internet itself, traffic on the Internet and the speed and current traffic conditions of the site your visiting. U.S. Robotics, Cardinal, Rockwell, and other manufacturers have developed modems capable of 56k speeds over standard telephone lines. U.S. Robotics line of modems called X2 uses an “asymmetric” scheme. This lets you download at speeds up to 56kbps from any on-line service or ISP ...
