Product and Software: This article applies to Aruba AP-65 and AP-70 with all ArubaOS versions.
The AP-70 transmits a stronger RF signal. For 802.1bg, the maximum difference in antenna gain is about 1.5 dBi. For 802.11a, the difference varies much more by channel and is in the range of 1 to 4 dBi.
This means that, in terms of range, the AP-65 has a difference of about 16% reduced distance for 802.11bg, and for 802.11a, it is up to 37% reduced (for some channels).
Does this difference matter?
· For 802.11bg, this difference should be negligible, given the other variables in the environment. The +/-1.5 dB of the antenna is not a critical consideration on which AP to choose. If only bg access is the goal, compare cost and features of the APs (such as, second Ethernet port).
· For 802.11a, with ceilings above 10 to 12 ft, the higher gain of the AP-70 is of diminishing value because the increased gain is directed horizontally at the next APs on the ceiling and not at the clients. For ceilings up to 25 ft, we prefer the lower gain of the AP-65 for this reason. For ceilings above 25 ft, we suggest the AP-105 or an AP with external antennas like the AP-60, AP-70, or AP-124 with downtilt omnis. The signal from the AP-65 will get down to the clients in the vertical direction better than the AP-70. The apparent ability to reduce AP density by using the AP-70 and a higher gain antenna is a 2D consideration only, not a 3D one. So, for the same density of APs, coverage will likely be similar to worse with the AP-70. If 802.11a is a requirement, the density should be as needed for the AP-65 deployment. Using the AP-70 (or any higher-gain omni antenna) in a high ceiling environment will result in a greater difference between the expected and actual results. You will see a difference in the results because the increased coverage predicted by the higher antenna gain does not materialize except at the ceiling height.
The datasheets for the AP-65 and AP-70 internal antennas are attached.