replacing omnidirectional antenna with a directional antenna

This is the exam our teacher gave us today.

we replace an omnidirectional antenna with Gain=0 dB with a directional
antenna with Gain=10 dB. give 3 reasons why the connection is
disconnected with this replacement.

can anyone help me plz?
ex my bad english hope u understand the question.

On 23 Nov 2006 09:23:43 -0800, "(E-Mail Removed)"
<(E-Mail Removed)> wrote in
<(E-Mail Removed) .com>:

>This is the exam our teacher gave us today.
>
>we replace an omnidirectional antenna with Gain=0 dB with a directional
>antenna with Gain=10 dB. give 3 reasons why the connection is
>disconnected with this replacement.
>
>can anyone help me plz?
>ex my bad english hope u understand the question.

Usenet isn't for homework assignments.
Use Google to do research on the Web.

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<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
> This is the exam our teacher gave us today.
>
> we replace an omnidirectional antenna with Gain=0 dB with a directional
> antenna with Gain=10 dB. give 3 reasons why the connection is
> disconnected with this replacement.
>
> can anyone help me plz?
> ex my bad english hope u understand the question.
>

1) the end user is not in the direction of coverage.
2) if the user is in the directional coverage, and close to the source the
increased power may be swamping the RX, causing the connection to drop

"John Navas" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On 23 Nov 2006 09:23:43 -0800, "(E-Mail Removed)"
> <(E-Mail Removed)> wrote in
> <(E-Mail Removed) .com>:
>
> >This is the exam our teacher gave us today.
> >
> >we replace an omnidirectional antenna with Gain=0 dB with a directional
> >antenna with Gain=10 dB. give 3 reasons why the connection is
> >disconnected with this replacement.
> >
> >can anyone help me plz?
> >ex my bad english hope u understand the question.
>
> Usenet isn't for homework assignments.
> Use Google to do research on the Web.
I agree with you about the homework part.
But just speculating what may have happened, and just listing the end result
would be interesting to see what people think may happen.
Heck off the top of my head I can only think of two reasons.

>
> --
> Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
> John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
> Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
> Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

On Thu, 23 Nov 2006 09:13:44 -0900, "Dana" <(E-Mail Removed)> wrote in
<(E-Mail Removed)>:

>"John Navas" <(E-Mail Removed)> wrote in message
>news:(E-Mail Removed).. .
>> On 23 Nov 2006 09:23:43 -0800, "(E-Mail Removed)"
>> <(E-Mail Removed)> wrote in
>> <(E-Mail Removed) .com>:
>>
>> >This is the exam our teacher gave us today.
>> >
>> >we replace an omnidirectional antenna with Gain=0 dB with a directional
>> >antenna with Gain=10 dB. give 3 reasons why the connection is
>> >disconnected with this replacement.
>> >
>> >can anyone help me plz?
>> >ex my bad english hope u understand the question.
>>
>> Usenet isn't for homework assignments.
>> Use Google to do research on the Web.
>I agree with you about the homework part.
>But just speculating what may have happened, and just listing the end result
>would be interesting to see what people think may happen.
>Heck off the top of my head I can only think of two reasons.

Me too, but you really don't learn much when someone else supplies the
answer.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

Dana wrote:
> I agree with you about the homework part.
> But just speculating what may have happened, and just listing the end result
> would be interesting to see what people think may happen.
> Heck off the top of my head I can only think of two reasons.

The kid seems to have decent internet skills as he found this news group.

So lets assume he has indeed tried to find the answer. I suspect you won't
find the answer to the question as worded as such. Insufficient information
and it appears its an essay required answer instead of multiple guess...
this would allow some leeway in explaining his answers (and if answered
correctly, point out the poorly worded question).

Granted, a client on the back side of a directional access point would
loose coverage, but we don't know which antenna was changed out - the AP
or client side.

How much coax loss was introduced into the system? Did several or all
of the client points loose connection? Which antenna was replaced, the
AP side or client side?

On Thu, 23 Nov 2006 18:33:25 GMT, decaturtxcowboy
<nope_none_@nowayspam.com> wrote in
<VPl9h.9543$(E-Mail Removed)> :

>Dana wrote:
>> I agree with you about the homework part.
>> But just speculating what may have happened, and just listing the end result
>> would be interesting to see what people think may happen.
>> Heck off the top of my head I can only think of two reasons.
>
>The kid seems to have decent internet skills as he found this news group.

Nothing special about that, and irrelevant to his assignment.

It's a well-accepted principle that Usenet isn't for homework
assignments -- see Usenet guidelines.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

"Dana" <(E-Mail Removed)> hath wroth:

>
><(E-Mail Removed)> wrote in message
>news:(E-Mail Removed) roups.com...
>> This is the exam our teacher gave us today.
>>
>> we replace an omnidirectional antenna with Gain=0 dB with a directional
>> antenna with Gain=10 dB. give 3 reasons why the connection is
>> disconnected with this replacement.
>>
>> can anyone help me plz?
>> ex my bad english hope u understand the question.

>1) the end user is not in the direction of coverage.
>2) if the user is in the directional coverage, and close to the source the
>increased power may be swamping the RX, causing the connection to drop

Incidentally, the original question came from the Soroush Resaneh
Institute in Tehran, Iran via mellat.tehran.sinet.ir
<http://sinet.ir/English/>

Well, now that you've given away 2 out of 3 answers, I can become part
of the problem instead of the solution. Might as well give up any
pretense of at being helpful. However, in the future, I suggest you
avoid answering student homework questions as they are expected to do
their own research and usually have much better learning resources at
their skools than are available on the internet.

3) Increased antenna gain causes distant source of interference to
now become a problem.



--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> "Dana" <(E-Mail Removed)> hath wroth:
>
> >
> ><(E-Mail Removed)> wrote in message
> >news:(E-Mail Removed) roups.com...
> >> This is the exam our teacher gave us today.
> >>
> >> we replace an omnidirectional antenna with Gain=0 dB with a directional
> >> antenna with Gain=10 dB. give 3 reasons why the connection is
> >> disconnected with this replacement.
> >>
> >> can anyone help me plz?
> >> ex my bad english hope u understand the question.
>
> >1) the end user is not in the direction of coverage.
> >2) if the user is in the directional coverage, and close to the source
the
> >increased power may be swamping the RX, causing the connection to drop
>
> Incidentally, the original question came from the Soroush Resaneh
> Institute in Tehran, Iran via mellat.tehran.sinet.ir
> <http://sinet.ir/English/>
>
> Well, now that you've given away 2 out of 3 answers, I can become part
> of the problem instead of the solution. Might as well give up any
> pretense of at being helpful. However, in the future, I suggest you
> avoid answering student homework questions as they are expected to do
> their own research and usually have much better learning resources at
> their skools than are available on the internet.
>
> 3) Increased antenna gain causes distant source of interference to
> now become a problem.

So obvious I overlooked that as an answer. But then my two answers were
obvious as well.
I kind of dissagree with the homework thing, especially if you only give
generic answers like we did, and leave it to the original poster as to find
out why those answers may indeed be the answers they are looking for.

>
>
>
> --
> Jeff Liebermann (E-Mail Removed)
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558

i'm so terribly sorry i didn't read group's guidelines.
i didn't know i wasn't allowed to ask for homework assignments.
the problem is that our proffesor didn't teach antenna well. he spoke
about them only 30 minutes.
also the text book he intorduced us doesn't explain much about antenna.
(the book is "Data Communications, Computer Networks and Open Systems"
by Fred Halsall.
we have only studied chapter one & two.)

thanks alot for ur help. i searched myself 'n here is what i came up
with (i'm sorry if i'm not able to explain well in english):

1. maybe the main lobe of our directional antenna is not directed
toward the receiver.
(the end user is not in the direction of coverage)

2.maybe polarization of the new antenna is not as of the receiver''s.

3.maybe the the propagation bandwidth of the transmitter antenna is not
equal to the receiver's bandwidth.