Dili Village Telco Part 5

Friday was day three of trying to get the first mesh link working! On day two this was starting to get me down. How can it be this hard to set up a simple 300m link with Mesh Potatoes? By day three I was resigned to just plugging away until we got it working, even if it meant importing some 5 GHz gear. Exploring the ease-of-installation meme is exactly what we are here to do. And another trip back to Timor would not such a bad thing, I like it here.

I really want to set up some links and gather a few days performance data with Smokeping and Munin before I leave.

One possibility of improving the link was fitting a directional antenna at one or both ends. The Fongtil guys had an assortment of antennas from previous projects. We tested them but couldn’t get signal levels better than the standard MP omni.

We have two Nanostations running the Supernode firmware. So we decided to fit one to the Blind Society mast. As described in previous post we reasoned this would give us some benefit from the directional Nanostation antenna and increased link margin. The disadvantage is the Blind Society would have poor omni coverage for expanding the mesh. So we decided to fit both a Mesh Potato and the Nanostation to the same mast.

We gathered up the team and a bunch of equipment and headed back to the Blind Society. Ase (Ah-say) and Mateus did an amazing poll climbing trick. They just grabbed a pole with both ends and went hurtling upwards using arm power alone. It was like Batman (the TV series, not the mesh routing) except I swear they were sliding up the pole. These guys have a very high power-weight ratio.

The results were really good, 0% packet loss on short and long ping packets, and a Batman score between 220 and 255. The ping tests I used were:
# ping -c 100 -i 0.1 -q
# ping -c 100 -i 0.1 -s 1400 -q

Sending the packets at 100ms intervals gave the link an additional hammering. Finally, the breakthrough we had been waiting for! The received signal was measuring -54dBm at both ends, a very strong Wifi signal.

I hope there aren’t too many other links like this one – Nanostations are expensive kit. We placed both the Nanostation and the MP01 on the Blind Society mast. They mesh together automatically (very cool) so the Blind Society get a phone and the mesh is spread in an omnidirectional pattern. Not so cool – we used two nodes (MP plus Nanostation) to do the job of one.

Next milestone is to see if this link can stay reliable for 24 hours.

We also installed another node at the University campus across the road from the blind. Ase (Ah-say) and Matues showed some more climbing tricks:

So now we have 4 nodes, consisting of 2 Nanostations and and two Mesh Potatoes. There is still an issue with the links between the Fongtil tower and inside the Fongtil building, we will debug that and so some more network training tomorrow.

I am sweaty, sunburnt, hot, a little dehydrated, but mildly happy. We inch forward.


Dili Village Telco Project Wiki
Dili Village Telco Part 1
Dili Village Telco Part 2
Dili Village Telco Part 3
Dili Village Telco Part 4