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  #71  
Old 02-16-2009, 07:34 PM
Franklin Franklin is offline
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Default Sd

Quote:
Originally Posted by Terry Roberts
Reggie; I have a paper put out by Alcatel explaining all the different diversity systems and networks. It contains all the formulae required would that help?
Hello Terry

Please, would you send me this Alcatel paper.

Thank you in advance

Franklin
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  #72  
Old 02-17-2009, 04:37 AM
ImranSabir ImranSabir is offline
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Location: Pakistan
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Smile

Availability is related to the Rain fading mechanism. Its the rain which decide the link's availability. Since at 6GHz the rain fading is almost negligible so the Multipath Fading is actual parameter that you have to take care of while planning at lower bands.
As mentioned above in a thread as well, the usage of diversity antennae will improve the link's performance by minimizing the affect of Multipath fading so you instead of looking into the Availability parameter better concentrate at Multipath Fading factor by changing the antennae size using the diversity mechanism and you will note that this parameter will change by changing the antennae size as well.
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  #73  
Old 02-17-2009, 04:41 AM
gaboincanada gaboincanada is offline
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Quote:
Originally Posted by Reggie
Just consider a 65 km path with average terrain and average climatic conditions (no special case) in the 6 GHz band.

When I design the path with only one 12 ft antenna on each side, I get approximately 99.999% annual availability and 99.995% worst month availability.

Then, I decided to redesign the same path with space diversity antennas and I get the same availability results with two 8 ft antennas on each side.

Now, which other criterias must I consider to decide which configuration to install in the field?

I am not looking for mechanical considerations, such as the tower loading, but for RF criterias that I can look at when I design the path. Many people tell me that for a 65 km path I should install diversity antennas, but they are not able to tell me why!

So, I would like to get theoretical considerations to take into account when I design the paths, because we all know that for each single antenna configuration we can get a space diversity antenna combination that will produce the same reliability results, no matter the distance!

Thank you all in advance!
Reggie,
There are several aspects to answer your question.
I wish I had the profile in front of me to tell you.
But, in few words, these are my considerations:
1.- Space Diversity helps and provides a great improvement for selective fading. Long paths are prone to intense selective fading activity, and SD is the best countermeasure.
2.- SD can be very helpful to minimize the effects of ducts and reflections.
3.- One 12 feet antenna represents more wind-load than two 8 feet antenna on a tower. You should weigh the costs of the extra transmission line and antenna and also additional SD receivers against the cost of a more sturdy tower to support just one huge antenna, and see how the figures look. I think the tower will be much more expensive than the antenna+waveguide set
4.- If you want to minimize the amount of antennas, you may also consider the hybrid SD, with one antenna at one side and two antennas at the other side. It is not as effective as the standard SD, but it may be a good trade-off.

I hope this helps.

Gab
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  #74  
Old 09-04-2009, 02:14 PM
Suraj Suraj is offline
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Join Date: Jul 2009
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Default

Please send the alcatel documents to me too @ findsuraj444@hotmail.com
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  #75  
Old 10-29-2009, 12:12 PM
Farhan samad Farhan samad is offline
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Default Space diversity calculation

Can any one send me alcatel space diversity calculation document on mfarhan_76@yahoo.com

Thanks in advance

Farhan
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  #76  
Old 11-25-2009, 07:28 AM
Zaygham Nawaz Zaygham Nawaz is offline
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Can some one please forward that alcatel document to me on

zaygham.nawaz@gmail.com

Much appreciated.

Best Regards,
Zaygham Nawaz
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  #77  
Old 12-02-2009, 04:51 PM
wisp_engineer wisp_engineer is offline
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If anyone has a copy of this can you PM me and I will give you my email address.


Thanks!
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  #78  
Old 02-14-2012, 02:34 PM
justfawad justfawad is offline
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Join Date: Dec 2009
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Dear Terry Roberts,


Could you please send that paper put out by Alcatel explaining all the different diversity systems and networks to my following mail ID.

justfawad@gmail.com

Many thanks for your kind help.

Malik Fawad
Karachi
Pakistan
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  #79  
Old 02-15-2012, 08:33 PM
Louis Hayworth Louis Hayworth is offline
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Location: Europe
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Go here for info...

http://www.micropath.net/downloads/D...ngineering.pdf

or here

http://www.alcatel-lucent.com/bstj/v...j49-8-1827.pdf

or here

http://www.activeonline.com.au/PPRLE...k%20v1%202.pdf
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  #80  
Old 02-22-2012, 10:27 AM
amraja amraja is offline
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Join Date: Feb 2006
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Default Alcatel SD Files

Hi Terry ,

Coul you please send me the Alcatel document to my e-mail amraja@altahreer.net

Thanks ,
Raja
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