Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : Ascend Communications (ASND) -- Ignore unavailable to you. Want to Upgrade?

To: Steve Rolfe who wrote (23632)	11/16/1997 1:04:00 AM
From: Steve Rolfe	Respond to of 61433

Another helpful article for those new to the X2/Flex issues... Coming to Terms Originally published in the December 1997 issue As you research and shop for a modem, you'll run into lots of acronyms and communications jargon, both in our articles and on product packaging. Here's a quick primer to help you wade through common terminology. Bit Robbing: A technique employed to transmit phone-signaling information by embedding it in the data being sent. This works well in voice communications, but adversely affects data calls. A bit is "robbed" every six frames for signaling use when a call is routed through a digital T1 line. Central Office (CO): The telephone-company facility that connects individual telephone lines in a limited geographical area. Digital Signal Processor (DSP): A chip used for operating on the digitized rendition of an analog waveform. Echo: A repetition of a signal in a communications line, which acts as noise. The "bounced" signal is out of phase and thus distorts the original signal. Despite echo-cancellation filters, echo is occasionally encountered at varying levels on phone lines. Intermodulation Distortion (IMD): A form of distortion where different-frequency components of a common signal interact, creating signal noise, usually at harmonic values of the summed frequencies. IMD in phone lines is usually found in the conversion from four-wire lines to two-wire local-loop lines at the local phone-company office. International Telecommunications Union (ITU): An international organization that defines telecommunications standards and equipment. Formerly called the CCITT (Consultative Committee for International Telephony and Telegraphy). K56Flex: A 56Kbps modem communications technology coauthored by Lucent Technologies and Rockwell Semiconductor Systems. It combines Lucent's v.flex2 and Rockwell's K56Plus technologies. K56Plus: Rockwell's original proprietary technology for 56Kbps modem communications. Local Loop: The analog phone lines between your home or office and the CO. mu Law: A codec algorithm used by digital telephone switches in the U.S. to convert analog transmissions to digital signals. Plain Old Telephone Service (POTS): The traditional phone system based on analog phone lines. Public Switched Telephone Network (PSTN): The worldwide voice telephone network. Pulse Code Modulation (PCM): A common method for digitally encoding an analog waveform for transmission. Quantization Noise: Signal errors induced into a transmission while converting from an analog waveform to digital pulses. T1: A digital network link that is capable of transmitting data at 1.544 Mbps. Trunk-Line Signal Loss: This occurs when adjustments are made to the signal to match power levels at phone-company switches. The signal is attenuated in the digital domain, and so some signal degradation is introduced as parts of the signal are compressed. v.flex2: Lucent's original proprietary technology for 56Kbps modem communications. x2: 3Com/U.S. Robotics' proprietary technology for 56Kbps modem communications.