# SM Power Levels at AP

There are currently only 4 customers connected to this AP, and are all within 35 degrees of AP antenna. All customers are within 2 miles of AP, but there is some heavy foliage to penetrate through. Because of the small coverage area and minimal customers, we have elected to use a M2 17 dBi yagi antena at the AP, and M2 17 dBi yagi antennas at the SM. The power levels at the SM are all good, -70 through -65, but power levels at the AP for each SM are -81 through -78. Does anyone know why we would see such a difference in power levels from AP than SM? Also, spectrum analysis is good on both AP and SM.

You must have same version an Ap and Sm!!

I think you have a Problem with LOS

I’m not sure of the beamwidths (vertical and horizontal) on the 17db yagi, but I would think you might be a little better off with a stinger or panel antenna at the AP rather than a yagi unless you are doing more of a point to point link.

You may be lacking enough vertical and/or horizontal beamwidth at the AP to serve the area you are looking at. You might also need downtilt in the equation depending on how high up your AP is.

Somebody else might have some more input in this scenario but this is just what my thoughts are.

One other thing to keep in mind - if you are under FCC regulation, a 17db at the AP with the AP running at full 26db output will put you over the max EIRP for the 900 band (max EIRP being 36db). Just something to think about.

Both AP and SMs are running v9.4.2. Saw same results prior running v8.2.7, v9.0, v9.3, v9.4. Because of the small coverage area, the yagi antenna seemed like a good choice, even though a base station antenna would be more robust. All customers are Non-LoS, so the poor or weak signal is expected… just not sure why the signal levels would differ so much (about 10 dB) between AP and SM. AP sees SM at -80, SM sees AP at -70.

We used yagi’s in the past with APs without any good luck, if you are not within the very near ±3db zone of that antenna, your SMs will not be heard very well by that AP, your best off checking the performance from sector panel see what happens, I bet you see an imporvement, and watch the the power output fines are pretty expensive…