Context
I recently moved into a new house. Sadly, there was still no fiber connectivity in my suburb. That was quite painful as where I lived before I had a good 10Gbits/s internet connectivity.
When I subscribed to the ADSL and after setting up everything I realized that indeed it was really painful to work on a 5 Mbit/s internet connection; just pulling a base docker image took time. It’s sad because Free (the ADSL provider) gives you a fixed IPv4 and a /64 IPv6 subnet (well, a /56 would be better, but oh well).
I then bought a 4G modem and an unlimited 4G data SIM card from Yallo.ch. With a Ubiquiti EdgeRouter X I was able to do some dual-WAN in order to use the 4G connection and fallback to the ADSL one when the cell tower saturated (and this happened a lot during the COVID confinement).
The tipping point
After some months I started getting tired with all this setup; I wanted the real thing: a fiber connection with static IPs for my homelab.
I started looking around and then I realized that I had a direct line of sight with my parent’s home. This was getting interesting:
Ubiquity’s link tool reported that the link would be of around 21 km in total length and that using Rocket M5’s modems the total speed would reach 85 Mbits/s.
As you can see in the elevation profile, the big flat in the middle is actually the Léman (sometimes misspelled “Lake Geneva”). My p2p link would start from France, cross Switzerland, and end in France again!
Searching for radios
I started looking on eBay and I found a set of used Rocket M5 for 80 €. I decided to combine them with a 30 dBi dish (RD-5G-30).
The BOM was as follow:
| Item | Quantity | Total cost |
|---|---|---|
| Rocket M5 | 2 | 80 € |
| 30 dBi Dish | 2 | 230 € |
| Total | 310 € |
Mounting the hardware
Mounting the hardware was quite easy. You just have to be careful with drip loops so that water doesn’t leak into your home and with vibrations of the mast.
CRA AP
The CRA AP was the access point mounted on my house. You can see the old satellite dish (that I will have to remove someday) and the external 4G antenna.
Here, the alignment was quite easy to do: I pointed it roughly at the city and immediately started seeing a SSID of a construction company with the name of the city in it (maybe used for the cranes ?). I just had to adjust the antenna in the two planes for it to be aligned with the other antenna.
CES AP
A week after I went to my parents house and installed the other end of the link.
As you can see in the following picture, my house is directly behind this big tree.
When I started aligning the other antenna I started sweating a lot. We discussed the tree matter with a friend at work and he was adamant that the tree would fuck the link up because of the link’s frequency (5 GHz). And indeed, as I started moving the antenna left and right I got nothing.
After a good 30 minutes of fiddling with the adjustment screws, and as I was close to give up, I decided to increase the transmit power of the two antennas to the maximum permissible (i.e. 500 mW)… and the AP appeared instantly 🎉 !
Link overview
