• P416 Figure 10.52, bottom left:

    "Transit ASEL responder" should read "Transmit ASEL responder"


  • P415, 3rd and 4th lines down from section 2 of "Transmit ASEL", give 0/6 for ASEL command subfield.

    Figure 10.52 gives 0/1 under "Tx ASEL sounding indication" headers


  • P67/70 Question 7 answer should be A,C,E
    P85 Fig 3.13 Timing and size of second client PS-Poll is off
    P145-146 Exercise 4.1 No "Product Evals" folder or ch04_capture1.PCAP file on CD I received

  • P380, Fig 10.16, right hand set of blocks:

    "Data+RGB" should read "Data+RDG"

    "Destination = STA" in top right block should read "Destination = STA 1"


  • P380, Fig 10.16:

    "Duration ID"; perhaps a better way to show this would be "Duration/ID"

    Duration values of 11 and 12 given may cause confusion, assuming that the end of the diagram illustrates the end of the TXOP initiated by the RD initiator.


  • P408, Figure 10.43 Protocol Decode

    Perhaps a note to explain the occurrence of the entry ?MCS Request Sequence Indentifier? in the protocol decode ( 4th line up from last line of decode );

    When the MAI sub field is set to something other than 1110 ( 14 ), it indicates that the sub field should be interpreted as containing two sub-fields of it?s own:

    1. A single bit MRQ subfield

    2. A three bit MSI ( MCS Request Sequence Identifier ) subfield ( the subfield shown in the decode )


  • P 411 section 2, lines 5 and 6:

    "Upon receipt of this sounding PPDU, the calibration responder can estimate the MIMO channel"

    should read

    "Upon receipt of this sounding PPDU, the calibration initiator can estimate the MIMO channel"


  • P423 second last paragraph, last line:

    Suggest changing "use" to "using"


  • P442 "Note", 2nd line down:

    "You should reference Appendix B, "WLAN Vendor List"......."

    No Appendix B in my copy of the book.


  • Rather an important one:

    P 446 Second last paragraph, six lines down:

    ?If you double the distance, the amount of energy of the wave will be one quarter of it?s starting energy?.

    We have to be very careful with one, as in the format above, that is not true.

    In a perfect vacuum with no obstacles , an electromagnetic signal will never lose any energy, no matter how far it travels. The nearest we can come to this is in outer space. A small amount of energy is lost ( absolutely tiny ) due to small amounts of ?space dust? etc when we consider a signal being sent from ( say ) NASAs Deep Space Network to one of the Mars Rovers.

    If outer space had no planets, no space dust etc, and we had no atmosphere on Earth, then a signal transmitted from earth to space would not lose any energy. In other words, if we had an RF scoop that could ?pick up? every ?last fraction? of the RF signal, then we would collect exactly the same amount of energy as was transmitted.

    In a pond or in the sea, a small amount of energy is lost due to friction etc.

    If we consider a ?unit area? of say one square meter, and we measure the energy content at various distances away from the scource, then we can make statements about the amount of energy having dropped ( per unit area ).

    It?s just the way it has been ?worded?, as the paragraph starts off by mentioning part of the area issue.


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