10-01-2005 02:12 AM - edited 07-04-2021 11:10 AM
hi all
i have a 1300 series AP/BR.
part no:AIR-BR1310G-E-K9-R (ETSI)
my external antenna is "AIR-ANT24120" 12dbi.Bcoz of some TRA issues i'm forced to use 5.725-5850.From TRA i got the instruction that, if you put 12 dbi or 13.5 dbi antenna the maximum power is should not exceed " 2W max.mean EIRP".
20 dbm/Mhz max. mean EIRP density.
so in this case how can i proceed with
1300 AP/BR. will this unit support 5.7 band.i need to change this unit? please give your suggestions.
Regds
Binoy.
10-01-2005 07:22 AM
To complete the calculation, it's necessary to know how much of what kind of cable is connecting the AP to the antenna (to calculate loss of the "intentional radiator").
For example, if you have 50 feet of coax that's rated at 6db loss per hundred feet, you are introducing about 3db f loss (then add another ~.25 db loss for each connector - AP-Cable-arrestor-cable-antenna).
In the above example, if the AP was putting out 20mw (13dbm):
50 feet of coax@ -6db/100 feet - -3db
four connectors @ -.25db ------- -1db
antenna @ 13.5db --------------- +13.5
Total gain: +9.5db
9.5db = 3db + 3db + 3db +.5db
Starting with 20mw (13dbm):
20mw * +3db = 40mw (16dbm)
40mw * +3db = 80mw (19dbm)
80mw * +3db = 160mw(22dbm)
.5db = who cares ;-}
dbm = db gain relative to 1 milliwat (mw)
2W = 2000mw = 33dbm
100mw = 20dbm
Here's a link to a mw/dbm calculator.
There's also a dbm/mw conversion table in the WebGUI of the AP (in the "Interfaces" screen where you'd adjust your power).
Short version:once you have the total gain of the system (connectors(-), coax(-), arrestor(-), antenna (+)), adjust your output power to stay below your local max Effective Isotropic Radiated Power (EIRP).
Good Luck
Scott
10-01-2005 08:25 PM
hi scott thanks for your time.
scott my situation i will explain it to you.
i have 2 1300 series units.with 2 types of antennas.
12 dbi and 13.5 dbi.from TRA i got the information that 1300 unit is ok, but when it comes to the external antenna they are saying it's transmission power is more.
according to TRA people, transmission power should not exceed 2watt max.mean E.I.R.P
how can i utilise my 1300 & 12 dbi and 13.5 dbi antenna's for this.
if i want to go for 5.x Ghz will this 1300 support?
or i need to go for 1400, will this 1400 support 5.x Ghz?
Regds
Binoy
01-23-2006 06:45 PM
The 1300 series bridge supports B/G radio, which is in the 2.4 GHz range. If you wanted to use 5.x GHZ, you would need an A radio. This is used in the 1400 series.
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