# Forum

## CWDP Errata

• I'm a bit confused by the answer and explanation of question #5 on page 74 found in Chapter 2.

From appendix B of the CWNA official study guide on page 643, "UNII-1 FCC: 50 mW intentional radiator + up to 6 dBi antenna gain = EIRP".

50 mW = 17 dBm
17 dBm + 6 dBi = 23 dBm EIRP

In the question, we are using a 3 dBi antenna, but it's not clear if this is for the AP or for the client used to perform the survey.

If we are concerned about the power level of the AP, we could use the maximum allowed power of 50 mW at the IR. Answer would be B.

If we are concerned about the power level read by the survey client, we should not see anything above 26 dBm (23 dBm + 3 dBi), which is 400 mW. Not a choice.

In both cases, I would keep in mind that we will likely end up with an unbalanced link budget.

Is my logic correct ?

• P 250, 4th line down:

???.the same coverage area as the radios?

Should read:

??..the same coverage area as the 802.11a radios?

Dave

• P 28, Table 2.1, Channel ID at bottom:

58 and 60 should read 60 and 64 ( 4 channel units x 5 MHz per )

Dave

• Page 29 , table 2.1, channel 153 should be 5.765Ghz not 5.675Ghz.

• P 322 Lines 4 and 5
?The wavelength shrinks by the following factor: root 1.42 = .19?
Should read ???. root 1.42 = 1.19?

Dave

• P349 last paragraph. Lines 3 and 4:

??.MCS index 1 and 8 have the same data rates as 5 and 11 ).

Could be misinterpreted.

Although MCS rates 1 and 8 are the same ( 13/14.4 Long/Short Guard Interval ) and 5 and 11 are the same ( 52/57.8 ), they are not equal to each other.

Dave

• [s]p. 374 -- states that most applications use port 883 for HTTP/SSL communications. The diagrams get it right at port 443.[/s]

Sorry, this is in the CWSP book.

• The Vocera call command example in Chapter 2 (sorry, I have the Kindle version and don't know the page) might be wrong. It sayd that Matt Schwartz is trying to call Shawn Jackman, and the Vocera badge asks if he'd like to talk to Matt Schartz.

Did Vocera think he was calling himself? I assume the example meant to say that the Vocera was confirming that he'd like to call Shawn Jackman.

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