7 responses

  1. Ariel
    August 15, 2011

    Please, take a look at the numbers because they seem to be wrong. BR

    Reply

  2. zillah
    May 25, 2016

    Thx for this informative insight

    Reply

  3. Ray Brohinsky
    January 25, 2017

    Hi,
    The formatting of the list at the end of this otherwise good article is going to continue to make people crazy. I highly recommend that the list be lettered, rather than numbered, and all entries need a space after the letter-period. Then, the second entry will read, correctly,
    B. 1 MHz is equivalent to 10^6 Hz while 1 Mbps is equal to 10^6 bits per second.
    Currently, it reads:
    2.1 MHz is equivalent to 10^6 Hz while 1 Mbps is equal to 10^6 bits per second.
    and in search engines, without any formatting, it is very disturbing to see “2.1MHz is equivalent to 10^6” when “2. 1MHz is equivalent to 10^6” is meant.

    Reply

  4. zillah
    June 10, 2017

    Hi
    I guess definition of the frequency is wrong :
    ((By “frequency,” we mean the rate by which a wave would travel per second)),,,,,,,,,,this is the definition of a speed not a frequency

    frequency should be defined as the number of crests of a wave that move past a given point in a given unit of time.

    Reply

    • Ray Brohinsky
      June 28, 2017

      Zillah brings up an excellent point, which highlights a significant problem related to mbps as well:

      When we talk about Mhz, in physics, we are talking about a repeating waveform which has a feature (usually the one peak point) in each repeating cycle which is clearly related to the same relative location in all of the cycles. (Cycle, period, waveform generally refer to the same thing when identifying frequency, but not always: a signal which is complex, as we will see, has a more complex description). The use of speed-of-transmission to define frequency presumes that the characterics of the medium are known, and a single point has been chosen in the path of the ‘important’ part of the signal. This is actually very little use in discussing computer signals, since the speed in copper varies depending on the presence and distance to other materials. In properly-designed Coax cable, radiowaves tend to travel about 1 meter in one ns (nanosecond), but faster in space (where very little matter is involved), etc. So the “number of periods passing a selected point of reference in one second is preferred.

      This is also important to keep straight because those digital signals which are measured in Mbs are essentially made up of a series of sinewaves (as demonstrated by Fourier: complex signals in time can be decomposed into simple, orthonormal series of certain waveforms, sine/cosine, sine alone, Bernouli polynomial-based pulses, Walsh Functions, etc.) and the original signal’s survival in transmission can be judged by decomposing it into sines, considering the transmission media’s effect on each sine’s frequency, then recombining the resultingly affected sines to see the outcome.

      For instance, a Square wave will decompose to a series of sines, the fundamental being Y and each successive sine being an odd integer multiple of Y. If the transmission medium attenuates (reduces the size of) components beyond the 13th component (frequency = fundamental * 13, called the 13th Harmonic in physics) the sharp corners of the square wave will become rounded. If the medium consumes all of the fundamental, the result will look nothing like a square wave at all. More important still, a modulated rectangular wave (i.e., data stream) will be considerably more filled with discrete frequencies which keep the sides vertical, the tops and bottoms flat and maintain the data content viably readable.

      So Mhz is important in data transmission and design of motherboards and such.

      Mbs (or bits per second or baud) have differing meaning depending on whether the focus is on the data payload, the data plus any parity or additional bits (EDC, start, stop), or data packets with headers, packet-wrappers, etc, is being considered. If a protocol demands enough wrappers with headers and meta info portions and other stuff, a 100-byte payload can become bogged with millions of bytes of non-data extras.

      Reply

  5. Larry West
    May 25, 2018

    In the end, you must tell us what frequency our cables must propagate in terms of MHz, please.

    Reply

  6. Amin
    July 19, 2020

    Hi,
    Amin here..
    We have problem when our product coax cable with max 10MHz using for camera video with high speed data rate 12Gbps which cause mulfunction.
    Is that 10MHz not capable for 12Gbps ???
    How much MHz need for operate the camera video with high speed data rate till 12Gbps..?

    Reply

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