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mansoor2
2008-09-26, 10:13 PM
Radio Transmission Network Design using Pathloss 4.0 (http://pram.web.id/blog/2008/02/08/radio-transmission-network-design-using-pathloss-40/)
I write this article for my friendhttp://i.ixnp.com/images/v3.49/t.gif (http://fl3xu5.web.id/).Now he is trying to finish his final task about this subject. And maybefor all of you who need some material about Transmission NetworkDesign, I hope this article will be useful.
First of all, we need to now what exactly transmission network is…and why we need it. Transmission Network Subsystem is a part ofCellular Network System which is used for transmit traffic/signalinginformation between Nodes (BS/NodeB, BSC/RNC, MSC, and SGSN). Let’stake a look at this picture: (www.mobileguru.co.uk)
http://www.mobileguru.co.uk/Images/UMTS_Architecture.jpg
From the picture above, we can see that wireless network systemconsists of 3 main subsystem: UE/MS, BSS/RNS, and Core Network (PS/CS).So… where does the transmission network place? Yup… TransmissionNetwork is taking place between Network Element in BSS/RNS and betweenBSS/RNS - MSC/SGSN.
There are several alternatives which can be used for TransmissionNetwork media, such as Cooper, Optic, and Radio. In this article I’lltry to discuss the last one: Radio Transmission Network. As we knowthat Radio have some advantage:
rapid installation of microwave system and easily upgradable higher availability than cooper redeployable without causing lost of assests up to 1 STM to cover medium capacity (between RNC - MSC )Now, we are going to discuss about Transmission Network topology: (www.11h11.com)
http://www.11h11.com/hugobox/chaku/NetworkTopologies.png
So.. which one is the best topology that we can use to design? As weknow every topology has it’s own strong and weakness involved withavailability, capacity, cost, quality etc.,
Well if you have much time, you can do some experiment to calculateit :P, but it’s should be noted that in designing network, we have toreach the most Optimum Network. From my experience in designingnetwork, I can assure the Hybrid Network is the most effective one.
http://pram.web.id/blog/wp-content/uploads/2008/02/hybrid.JPG (http://pram.web.id/blog/wp-content/uploads/2008/02/hybrid.JPG)
OK then… let we move to next chapter.
In designing Radio Transmission, we have to consider several things:
Clearance criteria : K factor and Fresnel Zone Diffraction Analysis Refflection Analysis Rain Attenuation Frequency Planning and Interference Study Planning Tools using Pathloss 4.0Hmm… let’s dive deeper on the points above.
1. Clearance criteria : K factor and Fresnel Zone (www.danets.com)

nK factor :Also known as the effective earth’s radius factor, dependenton the refractivity gradient dn/dh of the region. Rays are refracteddue to the refractivity (n) decreases with height.
nK= 1/(1 + a x dn/dh),
where a = true earth radius
nUnder normal condition, dn/dh = -3.9 x 10-8
per meter
nWhich gives k = 1.33
http://www.danets.com/images/rf-0.gif
2. Diffraction Analysis
Deal with Clutter loss (function of antenna height, frequency, andearth radius factor). Diffraction Loss calculation consists of: knifeedge Diffraction, Average Diffraction, Isolated Obstacle Diffraction,Irregular Terrain, and Two Ray optic.
3. Reflection Analysis
Analyze the effects of a specular Reflection i.e., Relative Signalas a function of Antenna height, frequency, earth radius factor (tidalvariations).
http://www.mike-willis.com/Tutorial/PF_files/Picture133.gif
(from www.mike-willis.com) Should be noted that the fresnel zoneclearance applies to reflection. Fresnel zone enclose all points whichis the additional path length is less than ?/2. So the reflectingobject needs to be larger than 0.6 of the 1st fresnel zone or therewill be scattering loss.
4. Rain Attenuation
Is the function of the rain fall, the size of individual rain dropsand the percentage of the total path within the rain cell. Rainattenuation is a major concern at frequencies above 30 GHz.
Effect rain in microwave Signals are:
energy is attenuated due to radiation (scattering) and absorption, results reduced availability from quality point of view. when wavelength > size raindrop, scattering is predominant when wavelength < size raindrop, attenuation due absorption is dominant the actual fading depend on the frequency of the signal and the size of raindropITU-R recommends path length reduction for LOS microwave links ( ITU-P Rec. 530-7) which gives the effective path length:


deff
= d/(1+d/d0), where d0= 35 exp (-0.015 x R ); d=actual path length; R
<=100mm/hr. For R>100mm/hr, use the value R=100mm/hr.so, the effectiveattenuation due to rain is given by:A = Specific attenuation xEffective path lenghtA = (aR beta) x (deff), indBhehehe… too much theory huh :D5. Frequency Planning and InterferenceStudyInterference can be divided in to several categories: External Interference Interference from other systems using the same medium (radio, radar etc.) coupling between waveguides or bad grounding and shielding. Intra-system Interference (interference within the system it self) overreach interference adjacent section interference spur or junction interference6. Free space Loss
we can use this well known formula -> FSL =32.4 + 20 log (f)MHz + 20 log (d)km, for the complete equation this site http://i.ixnp.com/images/v3.49/t.gif (http://http//www.mike-willis.com/Tutorial/PF4.htm)will be useful for you. http://pram.web.id/blog/wp-includes/images/smilies/icon_razz.gif
7. Planning Tools using Excel and Pathloss 4.0
Now the most interesting part… yup, we can use planning tool toDesign and calculate all of the factors above. Planning tools that wehave to use are :
Path Profile calculation (Terrain Profile calculation using Excel or Pathloss 4.0 )http://pram.web.id/blog/wp-content/uploads/2008/02/path-profile.JPG (http://pram.web.id/blog/wp-content/uploads/2008/02/path-profile.JPG)
http://pram.web.id/blog/wp-content/uploads/2008/02/terrain-profile.JPG (http://pram.web.id/blog/wp-content/uploads/2008/02/terrain-profile.JPG)
http://pram.web.id/blog/wp-content/uploads/2008/02/terrain-data.JPG (http://pram.web.id/blog/wp-content/uploads/2008/02/terrain-data.JPG)
Link Budget calculation ( Using Pegasus or Pathloss 4.0 or Excel )http://pram.web.id/blog/wp-content/uploads/2008/02/link-budget.JPG (http://pram.web.id/blog/wp-content/uploads/2008/02/link-budget.JPG)
http://pram.web.id/blog/wp-content/uploads/2008/02/link-budget-2.JPG (http://pram.web.id/blog/wp-content/uploads/2008/02/link-budget-2.JPG)
Frequency Planning and Interference, diffraction Study ( Pathloss 4.0 )http://pram.web.id/blog/wp-content/uploads/2008/02/terrain-sagem2.JPG (http://pram.web.id/blog/wp-content/uploads/2008/02/terrain-sagem2.JPG)
http://pram.web.id/blog/wp-content/uploads/2008/02/diffraction.JPG (http://pram.web.id/blog/wp-content/uploads/2008/02/diffraction.JPG)
Digital or Topographical MapIt’s used to d0 Topographical analysis in order to get node candidates which is LOS each other.
I think this article is enough, hope it’ll be useful. Salam…

clive
2008-09-26, 11:01 PM
Thanks
This is too good.

miro
2008-09-27, 02:16 AM
thank you for the nice work

cloudsun
2008-09-27, 02:53 AM
very interesting knowledge share

kenshinz
2008-09-28, 06:36 AM
mansoor, may i ask u? pram.web.id is yours?

hassen
2008-09-28, 08:51 AM
Please share your presentation as HTML file

moh85
2008-09-28, 09:11 AM
the presentation in pdf format


http://pram.web.id/

[ Last edited by moh85 at 2008-9-29 00:58 ]

uel888
2008-09-28, 10:35 AM
Thanks for the share of knowledge.

hassen
2008-10-01, 10:36 PM
thank you friend

mike
2008-10-02, 12:09 AM
good document

Yachi
2008-10-02, 10:53 PM
good presentation friend

f1cy
2009-01-02, 05:56 PM
good job bro ;)

pram
2009-01-03, 02:30 AM
the presentation in pdf format


http://pram.web.id/

[ Last edited by moh85 at 2008-9-29 00:58 ]

Thanks for creating the pdf version :)

19walid
2009-03-31, 10:10 PM
thx for sharing

nguyenaituyen
2009-04-01, 01:12 AM
the presentation in pdf format


http://pram.web.id/

[ Last edited by moh85 at 2008-9-29 00:58 ]
i don't download it please help me!

dung_garlic
2010-04-13, 12:52 PM
I can't download attached files. It require 5 coints! who can help me this cause? thank advance!