Slashdot Mirror

← Back to Stories (view on slashdot.org)

WinDSL Coming?

Posted by Hemos on from the what-a-dumb-idea dept.

A number of people have written in in the last day or so regarding Motorola's rollout of software-based DSL modems. Apparently, this wil reduce the cost of the modems by 30-40%, meaning that they can put DSL into the lower-end of machines. I stand corrected - they aren't modems, they are bridges/routers - and I must be blind, because Linux support was specified in the release. IMDUM.

3 of 162 comments (clear)

  1. Technical accuracy? by Dave+Scherer · · Score: 5
    Okay everyone, repeat after me. There IS NO SUCH THING AS A DSL "MODEM". "D" in DSL is for digital.

    The following is quoted from this 3Com white paper

    For ADSL, the most talked-about xDSL technology, there are two competing modulation schemes: carrierless amplitude phase (CAP) modulation and discrete multitone (DMT) modulation. CAP and DMT use the same fundamental modulation technique--quadrature amplitude modulation (QAM)--but differ in the way they apply it.

    QAM, a bandwidth conservation process routinely used in modems, enables two digital carrier signals to occupy the same transmission bandwidth. With QAM, two independent message signals are used to modulate two carrier signals that have identical frequencies, but differ in amplitude and phase. QAM receivers are able to discern whether to use lower or higher numbers of amplitude and phase states to overcome noise and interference on the wire pair.

    Sounds like a MODEM to me!

  2. You can be wrong, but don't be bitchy too.. by consume · · Score: 5

    Please take a second and read T1.413, which is the ANSI standard for ADSL.

    OR you could just read Newton's Telecom Dictionary, under Modem:
    "The term "modem" is also applied (and correctly so, in the purely technical sense) to ISDN TAs (terminal adapters), ADSL TUs(Terminating Units), line drivers and short-haul modems.

    Instead of using a shift-keying encoding (typically Quarternary Phase Shift Keying for 28.8kbps and higher) xDSL uses CAP (Carrierless Amplitude Phase) or DMT (discrete multi-tone) to MOdulate the digital signals onto an analog medium and DEModulate the analog signals back into ATM cells or Ethernet frames.

    Keep attempting to be technical. We'll all still be here when you get back...

  3. Performance Hit by NMerriam · · Score: 5

    Unfortunately the side-effect of this is that people won't realize they're taking a big performance hit.

    Software modems, for the driver problems, aren't that big of a deal on windows because the Modem isn't using much processor time anyways.

    But this thing sounds like a real hog -- they couldn't implement it until now because anything below a P3-550 couldn't run it? This sounds like a great way for Intel to sell more processors.

    The folks who really appreciate high-speed access (other than Warez d00ds and Pr0n Kings) are gamers, and this is really gonna suck for folks who think they're getting a great deal, only to boot up and wonder why their new P3-1000 is slower playing Diablo 2 than their old P2-233 on a dial-up.

    And then of course the driver issues, when Loki comes out with Diablo 2/Linux (maybe?)...

    --
    Recursive: Adj. See Recursive.