Questions from CWNA Chapter 3

Chapter 3

Question 1

What other spread spectrum technologies exist other than FHSS and
DSSS? Are these of any importance to anyone taking the CWNA test?

Question 2

Do you agree that spread spectrum signals are harder to intercept and
demodulate? It seems to me with 802.11x standards, it would be easier
since any 802.11x radio should be able to intercept and demodulate a
signal. Well, that is partially true: 802.11a to 802.11a and
802.11b/g to 802.11b/g.

Question 3

Same with jamming and interference? I can see interference being less
of a problem with spread spectrum (less with FHSS than DSSS). But if
someone wants to intentionally jam a frequency, is it just as easy to
jam 22 or 83.5 MHz as it is 6 MHz?

Question 4

As for narrow band communications, the CWNA textbook states this
technology "uses only enough of the frequency spectrum to carry the
data signal, and no more." So what determines the amount of frequency
spectrum a radio uses? Could it be a T1 vs. DS-3? The T1 requiring
less than the DS-3?

Question 5

Does anyone know of some narrow band radios I should look up as a
reference? I downloaded the Aperto datasheet.

Question 6

Here is another statement, "More power is required to send a
transmission when using a smaller frequency range." Ok, so less
frequency range = more power. For what? The same distance and
throughput? If FHSS is only using 1 MHz per dwell time, that's a
pretty short frequency range so why doesn't it need more power? Did
the question make any sense?

Question 7

Anyone know where I can get a screen shot of noise? I want to compare
it to screen shots of FHSS and DSSS.

Question 8

Back to question 6, here is another statement regarding the same
thing. "we may use 1 MHz at 10 Watts with narrow band, but 20 MHz at
100mW with spread spectrum." Again, what is this giving us? The same
range and/or throughput???

Question 9

Would you agree that FHSS is more immune to jamming and interference
than DSSS?

Question 10

For FHSS I guess if there is interference, then there should be plenty
of spectrum left for resending the data. With DSSS, it isn't that
easy. I guess it would be much more easy to interfere with 22 MHz of
spectrum than the FHSS's 83.5 MHz (or technically, 79 MHz?)

Question 11

Is Bluetooth and 802.11x now compatible? If Bluetooth is still
hopping 1600/sec, then I wouldn't think so. I can't imagine being
able to run with Bluetooth and 802.11b on my iPaq at the same time.
The reason I ask is the textbook suggests "these two technologies
coexist peacefully."

Question 12

Here is an interesting one. The textbook suggests a WMAN uses the
same technology as a WLAN but then mentions at in many cases WMANs use
licensed frequencies. Are these radios using licensed frequencies
using spread spectrum??? I will begin looking this up once I'm done
with this post.

Well actually, that's it. Sorry for the long post and this is only 1
of 4 I'll post for Chapter 3 of the CWNA book.

--Skyler

Skyler Shipman wrote:
> Sorry for the long post and this is only 1
> of 4 I'll post for Chapter 3 of the CWNA book.

The copyrighted CWNA book?

--
John Miller
My email address: domain, n4vu.com; username, jsm

Osborn's Law:
Variables won't; constants aren't.

I'm posting questions and *quoted* references from the book.

Look, if you don't want to be helpful, do as all a favor and simply
filter my posts.

--Skyler


On Sun, 25 Jan 2004 13:10:04 GMT, John Miller <(E-Mail Removed)> wrote:

>Skyler Shipman wrote:
>> Sorry for the long post and this is only 1
>> of 4 I'll post for Chapter 3 of the CWNA book.
>
>The copyrighted CWNA book?

Skyler Shipman wrote:
> I'm posting questions and *quoted* references from the book.
>
> Look, if you don't want to be helpful, do as all a favor and simply
> filter my posts.

Up until your penultimate post, I have been nothing but helpful to you,
posting several bits of information that you must have found useful.

That's the end of that.
--
John Miller
My email address: domain, n4vu.com; username, jsm

short leg on process table

John.

My sincerest apology.

I got you confused with someone giving me grief. I thought the
copyright statement was another gab at me since I wasn't posting the
text of the book.

I do appreciate the information you have provided and would hate to
think my mistake would end any advice you have to offer.

If you can forgive me.....

is there something I don't remeber from English class (and copyrights)
that would prohibit me from asking questions with quoted statements?

And again John, I am sorry.

--Skyler


On Sun, 25 Jan 2004 14:47:01 GMT, John Miller <(E-Mail Removed)> wrote:

>Skyler Shipman wrote:
>> I'm posting questions and *quoted* references from the book.
>>
>> Look, if you don't want to be helpful, do as all a favor and simply
>> filter my posts.
>
>Up until your penultimate post, I have been nothing but helpful to you,
>posting several bits of information that you must have found useful.
>
>That's the end of that.