I’ve recently had justification to try out a pair of Ubiquiti airMAX LiteBeam M5s. The problem statement was a straightforward one: extend a LAN across the street to a second building.
The distance is about 20 metres, almost certainly close enough that a pair of UniFi Meshes could handle it – but one of those would cost as much as two LiteBeam M5s. And, ideally, two we’d use.
They’re highly directional, boasting circa 23dBi (which in the UK, that’s well beyond the license free Band B limit), they’re outdoor rated, and they come complete with PoE injectors and everything necessary to mount on a pole (less the pole itself).
Setup was easy enough. By default they host a web UI on 192.168.1.20, and are even preconfigured with an unencrypted wireless SSID of ubnt (I see what they did there). So at an absolute minimum (and absolutely not recommended) level, all you need do is login and change one to “AP” mode (leaving the other as the default “Station”). Point the two at each other, and you should shortly see the three green status lights confirming wired, wireless, and power is all connected and working. Traffic should flow.
Changing the SSID is a breeze, and WPA2 is supported out of the box. What took me a little longer was navigating the UK laws and regulations around output power and channel selection. What follows is my conclusion, and may be wrong. Double check these details for yourself if you’re following this as a how-to.
The UK appears to have 3 bands for 5GHz wireless – namely A, B, and C. Only C is licensed (and not expensively so), and appears intended for fairly long-range/high-power wireless links.
Band A is license free and typical for indoor WiFi. It covers the channels such equipment uses by default in this region. What I’ve read suggests it is “for indoor use” (although most homes and businesses I’ve seen also use it for general coverage outside their building on their own private land).
Band B is the middle ground. It’s also license free, but allows for a higher power (although far less than Band C) and is stated for both indoor and outdoor use.
The included Quick Start guide lacked a lot of detail around setup, so I resorted to researching online. Plenty of tutorials show how to get yourself up and running quickly, but provide no information on regional regulations. In particular, I noticed nearly all of them left the antenna power at the maximum.
The LiteBeam M5 appears to have several “sensible” software enforcements when it comes to power and channels. One set is triggered by you choosing your region on initial setup, another if you choose a specific channel, and a third if (and only if) you inform the access point that you’ve installed the reflective dish.
Ubiquiti describe two primary uses for the LiteBeam M5. One is with no dish attached – allowing you to mount the AP on the outside of a building to gain indoor coverage “behind” the antenna. The second – and I expect the far more popular – is with the reflective dish fitted to give a highly directional and long-distance link in the direction the antenna faces.
The following screenshot shows you what I concluded was one appropriate and UK compliant configuration. 40Mhz wide band B channels can be found on Wikipedia (channels 100 to 144, select the lowest frequency of the channel in the M5 configuration for your chosen channel width [20 or 40]), you’ll notice that the M5 automatically reduces the maximum antenna power to 7dBm:
For the other M5, the following settings:
In regards to aligning the two antenna, I made no special effort in the first instance. The alignment “tool” certainly works (under the drop-down at the top-left of the web UI), but in my testing … just eyeballing it worked.
With no further tuning – no particular effort in alignment – and, most notably, through two glass windows (they’re indoors at each location, waving at one another through two sets of double glazing), speeds sit at around 120Mbps (which exceeds the wired 100Mbps speed of the M5). The link is strong, plenty fast (for this use case scenario), and appears reliable.