Talk:ADSL transceiver

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From http://electronics.howstuffworks.com/vdsl.htm: 'Most residential customers call their DSL transceiver a DSL modem. The engineers at the telephone company or ISP call it an ATU-R, which stands for ADSL Transceiver Unit - Remote.' I'll leave it up to wiser heads than me to figure out what to make of this. 2006-05-19 03:30 UTC

The common usage "DSL Modem" is erroneous, oxymoronic, and frankly quite silly to anyone who actually knows what a modem is. The word modem is a contraction for MOdulator/DEModulator. Modulation is the process of converting a digital signal onto an analog carrier, and demodulation is the process of converting a modulated signal back to its original digital form. In an all-digital technology like ADSL, there are no analog signals and therefore there is nothing to modulate or demodulate. However, because ADSL Transceivers perform the same approximate function as an analog modem (serving as the intermediary between local computer equipment and the telephone network), the public at large seems insistent on incorrectly applying the word "modem" to this piece of equipment that is anything but a modem. 2006-09-03 04:20 UTC

Technically correct, but I guess you could say that the word "modem" originated from the name "modulator/demodulator", but now it is a generic word for a consumer device used to connect a computer to a telecommunications network. Maybe "ADSL router" would be a better name for the article, but not all ADSL modems have router functionality. -- Chuq 12:12, 4 September 2006 (UTC)

The usage "DSL Modem" is not erroneous. A DSL modem does indeed perform modulation and demodulation. It uses either Quadrature Amplitude Modulation (QAM) or Phase Shift Keying (PSK) modulation. Multiple modulated subcarriers are then combined into an OFDM stream. The distinction between this type of modem and a traditional one is that the traditional one modulates audio frequency signals whereas the DSL modem is upconverted to an RF band. But they both perform modulation and demodulation. The digital signals are not sent as baseband digital signals.

Our unsigned colleague is correct. The colloquial usage "DSL Modem" should be applied, because it is both widespread and technically correct. It modulates; it demodulates; it does all that a modem should do. It does not dial a phone number, and it does not limit its analog signal to one that can be carried by a loaded telephone cable or a ds0 channel. Those characteristics are commonplace, but they have never been part of the definition. As seen in the Modem article, a "modem" does not have to be voiceband limited. Voiceband, dial-up modems were merely the most common late 20th Century kind; they are not the technical or colloquial definition of "modem." Thus the name of the article should be restored to "DSL Modem."

Jim.henderson 15:02, 29 October 2006 (UTC)