Tenda O9 — 25km 5GHz 11ac 23dBi Gigabit Outdoor CPE

Buying it, and when not to

The O9 is a 25km 5GHz 11ac 23dBi gigabit outdoor CPE - AC Gen 2 Lite Beam class. Twenty-five kilometres of rated range from a high-gain 23dBi antenna, with a gigabit port.

This is the longest link in the catalogue and it is for genuine distance work: mast to mast, a town to an outlying village, a head office to a remote site, an ISP backhaul reaching a community the fibre will not get to for years. At 23dBi the beam is narrow, which is what produces the range and also what makes alignment critical - these links are made or lost on mounting rigidity and aiming, not on the radio. Budget proper masts, guying and alignment time, and use two units.

For anything under ten kilometres, the O6 and O3S are cheaper and easier to align, and a narrow beam on a short hop is an unnecessary risk. Long links also need clear line of sight with Fresnel clearance, so survey the path rather than assuming - at twenty-five kilometres, the earth's curvature and a single tall building both matter. For obstructed short paths the 2.4GHz O3 is the tolerant option. And as with every O-series unit, this is a point-to-point link, not outdoor WiFi coverage; that is the OAP1200's job.