Unfortunately I could not come to cccamp#19 so I missed a lot of fun. Fortunately, people shared a lot of technical details online so I was able to pull together a number of interesting details about the different microwave backhaul links that were put in place for the event as a backup to the cross country fiber that was somewhat unreliable at the previous camp due to the rodent population.
The last time I had a closer look in 2012, a wireless backhaul link speed of around 500 Mbit/s was state of the art. Things have progressed nicely in the last 5 years, we are now at 10 Gbit/s, symmetrical, of course.
Yes, that is right, 10 Gbit/s on a 80 GHz backhaul link with a bandwidth of 2000 MHz. Maximum link distance given by the hardware manufacturer for this speed is 2.5 km. For the camp, however, the link was run at this speed over 10 km. Breathtaking! This is more than enough capacity for any kind of 5G base station for years to come.
And some more technical details: 60 cm (2 feet) dishes with an opening angle of 0.5 degrees were used with a gain of 50 db, transmission power was 25 dBm, i.e. 0.3 Watts. During a pretty harsh thunderstorm, the link rate was temporarily reduced to 8.1 Gbit/s but that was it. Rock stable! Have a look here for pictures of the installation.
For good measure a second link in the 18 GHz band was deployed between the same sites with a line rate of 850 Mbit/s in case the 10 Gbit/s link would have been unstable. From what I can tell it was not needed.
And on top of that there was a third microwave link that is just as stunning but I will focus on that one in a separate post.