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Member
Reputation: 140
MW Frequency Channel
Say I have been given three spots for MW planning...7GHZ,15GHZ,18GHZ
Which frequency should i use for long and short backhaul MW link and why?
How do i divide the spots into channels for planning in Pathloss?
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2011-06-23 04:04 AM
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Re: MW Frequency Channel
7 Ghz for long haul. The lower your frequency the farther it can go, look at your wavelength formula c/f. Look at ETSI/ANSI for channel plans. The highest you can go for 7Ghz is 40Mhz bandwidth. Check the ANSI/ETSI epsecification.
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Member
Reputation: 157
Re: MW Frequency Channel
Originally Posted by
ritgail
Say I have been given three spots for MW planning...7GHZ,15GHZ,18GHZ
Which frequency should i use for long and short backhaul MW link and why?
How do i divide the spots into channels for planning in Pathloss?
Hi friends,
for 7GHz, you should use for long haul cause the attenuation in rain and pathloss is very low, depend on the capacity and channelize you will have several bandwidth such as : 28MHz, 29.5MHz, 40MHz...
for 15GHz, 18GHz, you can use for short backhaul depend on the distance and criteria of your country
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Member
Reputation: 140
Re: MW Frequency Channel
Ok i got it right, higher frequency for shorter HOP.. but if lower band such as 7GHz is used for urban area..it will require more height for fresnel clearance ?
Next for channel a band, please guide how to divide, does it depends upon modulation and carried traffic?
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Re: MW Frequency Channel
Again, its not practical to use 7Ghz for short hops. By regulation, 7Ghz doesnt allowed to be deployed for short distance. Use 23 Ghz, 18, Ghz, 15Ghz in case. ir use the 70, 80 and 90 Ghz for less than a mile.
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Member
Reputation: 140
Re: MW Frequency Channel
I have the calculation, where fresnel radius is shown. for lower bands it is bigger radius.. is it the fact???
calculation R=17.3√{d1d2/f(d1+d2)}
7GHz has 6m for 100%, 15 GHz 4.6m difference is 1.5m approx...
for 60% clearance it will require higher tower as per result.
Originally Posted by
harrypotter
Again, its not practical to use 7Ghz for short hops. By regulation, 7Ghz doesnt allowed to be deployed for short distance. Use 23 Ghz, 18, Ghz, 15Ghz in case. ir use the 70, 80 and 90 Ghz for less than a mile.
Last edited by ritgail; 2011-06-23 at 07:41 PM
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VIP Member
Reputation: 1401
Re: MW Frequency Channel
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