power estimation?

RouterOS Wireless Networking
1

at one install right now, a concrete high-rise on the beach, 20 stories high. we have 1 wrap2c with 2 x NMP-8602’s In AP MODE on EACH floor. theses are to serve guest wifi laptop people..so we get a mix of all kinds of client cards and combos


each of the 2 NMP-8602 radios, on each floor is connected to a 17dBi Pac wireless 90 degree sector antenna (the like 4 ft long ones). These are then mounted with the brackets (in reverse) directly to the wall, each on a different wall facing different directions.

(all 20 of the access points are hard wired back to a switch)


This all works pretty well to cover all of every floor. HOwever i have some complaints and ALOT of the wierd disconnected messages in the logs…i attribute this to the crappie 8602s…

My question is this, if i change out all the 8602s to CM9s (which i have been testing and love) what kind of power hit am i looking at considering that the cm9 is 63mw and the 8602 is 400mw…this is fed into that 17dbi antenna remember.

thanks for any input.

2

A couple of things. Your 400mw cards are much more powerfull than the laptop cards so you may be seing the AP signal but the ap’s probably are not seeing the laptop which is why you are getting disconnects. The CM9 will have a coverage area better matching the return path coverage area and with 20 ap’s in one building you will have less interference. Also look at how you are staggering the chanels and polarization (although hp is best for most laptops).
You may have been better off putting lower gain antennas, more aps and putting them in the halls or: using 60 degree sectors on the building accross the street so the signal is going through the windows with less resistance from the concrete and steel.


-J