Right place of Master AP

I would like to ask for your thoughts about the following scenario. I have two towers, on A I have the internet feed and on B there are two ePMP3000 APs with GPS sync on (no frequency reuse and DU ratio is 75/25). These two towers are connected with a PTP550e (GPS sync, no frequency reuse, DU ratio 30/70). The master AP is on tower B and i had to set the ratio to 30/70 because we need more data on the uplink side (internet feed is on tower A). I m thinking if it will have better performance to change the role on two 550e (master will be on tower A and i will change the ratio DU to 75/25). Thanks…

I am not understanding your question here. Are you saying you have a tower with internet connection and backhaul only and another with 2 ap’s and a backhaul to the first one? if so your 75/25 on the SM’s would translate to 75/25 on the backhaul of the same tower, 25/75 on the one without AP’s

From a pure performance point, it does not matter since you are not using frequency reuse.

from a planning perspective for future use, it does matter a lot.

first regardless of the frequencies used, if the radios are synced then the frame size and ration must be the same. you want all APs transmitting at the same time.
your backhaul (ptp) link as long as it is at least 50mhz away from your ptmp APs frequencies then you can effectively ignore it except it is a very good idea to use the same frame ratio to maintain data path continuity. so leaving the master on the far tower(twr2), your ratio would be 25/75 which would give you 25% twr2 to twr1 traffic and 75% twr1 to twr2.

frequency reuse can be implemented simply by having all the APs that point north and south one the same frequency with the same channel size , frame size, frame ratio and max distance.pick one direction to be front sector and the opposite will be back sector, I use North as front so all south APs are back sectors. make sure all APs are synced to the same source and if using packetflux to the same power injector version on each tower, there is a difference in canopy sync vs cambium sync though both work on the same equipment but canopy sync does not work properly on the e3k APs.

pic an antenna pattern ant stick to it. if you are using 4x 90 degree antennas then use an ABAB frequency plan, but dont throw an ABCABC plan into the middle of your system unless it is geographically isolated from all other towers. You can however use an ACBDACBD plan because you maintain the ABAB plan pattern

1 Like