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  1. #1
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    How the capacity for WiMAX had been calculated ?

    Can somebody enlighten me as to how the capacity has been calculted for WiMAX when it is said that
    " A maximum of 35 Mbps is achievable for a 64 QAM over 7 MHz bandwidth.

    2. How the coverage distance can be increased by lowering the frequency used.
    As an example if we use 700 MHz, the coverage would be more than if we use some 3.5GHz freuency in WiMAX.

    3. Can there be any significant difference in the capacity also in the lower frequency use.

    I would require these technical inputs to write a paper. Please help me forum....

    Thanks
    Sidd

    •   Alt9th February 2007, 18:48

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    wimax coverage distance

    Let me try:

    1. This we should try using Shannon's capacity formula with SNR term being replaced by Pe for 64-QAM. I am not sure since I did not verify it but I would try.

    2. High frequencies tend to attenuate at a higher rate with distance.

    3. Capacity is proportional to freq. bandwidth.

    Hope this helps. If yes, give me credit!



    •   Alt10th February 2007, 00:24

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  3. #3
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    wimax capacity calculations

    Thanks for the try but can you arrive at the 35 Mbps by calculation. Please demonstrate by formula
    Thanks



    •   Alt10th February 2007, 06:47

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    wimax capacity paper

    Quote Originally Posted by ricksidd
    2. How the coverage distance can be increased by lowering the frequency used.
    As an example if we use 700 MHz, the coverage would be more than if we use some 3.5GHz freuency in WiMAX.

    Thanks
    Sidd
    Wimax require a bidirectional communication (uplink and downlink).
    For the base station (BS) the coverage could be bigger at 700MHz but the propagation problems will be bigger as well. For the mobile station (MS)
    the 700MHz will be a pain in the ass. Imagine how look a 700Mhz omnidirectional antenna versus a 2.5Ghz or 3.5Ghz directional antenna on the MS. Then multiply with 3 for a simple MIMO transciever and imagine all the problems.
    In my opinion WIMAX in 700-800MHz is just policy and will not be operable very soon.



  5. #5
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    wimax+capacity

    Thanks
    I was just asking how the calculation to be done..
    By the way, GSM works in 800-900 MHz and their antennas are not ...........
    Sidd



    •   Alt10th February 2007, 18:12

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    wimax coverage istance

    http://www.edaboard.com/viewtopic.ph...ighlight=wimax

    This link present good papers about the Wimax capacity.
    Check this out.



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    shannon formula wimax

    Quote Originally Posted by ricksidd
    Thanks
    I was just asking how the calculation to be done..
    By the way, GSM works in 800-900 MHz and their antennas are not ...........
    Sidd
    If you consider a device with -3dbi gain an antenna, then you have right.
    The portable wimax devices does not have amplifiers better than +25...27dBm
    and a different chanelisation than GSM, and different spectral masks...etc. It's a different thing. There are GSM phones with >2W output.



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