olpc xo-1 b-test-4 radio range, extreme range

Summary

Two units were separated by 6.3km, at one end on the top of a mountain, but they were not able to communicate with each other, probably due to Fresnel Effect.

Configuration

XO-1 B4 labelled quozl-8 firmware Q2C26 build 612 aloft on 6m extension ladder at Coomooroo house,
XO-1 B4 labelled quozl-7 firmware Q2C26 build 612 taken to top of Mt Naman on foot.

Method

Setup mesh network manually without NetworkManager between units and verify as stable.
Elevate quozl-8 to position on ladder above house and verify pings continue.
Migrate quozl-7 to position on Mt Naman with lid closed, open lid, try pings, try scan.

Results

Mesh setup fine and was stable.
Pings continued when quozl-8 was elevated.
Pings could not be reproduced once quozl-7 was migrated to Mt Naman, and "iwlist eth0 scan" gave no results.

Conclusions

Not an appropriate test range, due to fresnel effect and terrain obstruction, or due to excessive 2.4GHz noise from nearby cities.

Also, since quozl-7 was transported with lid closed, it might not have recovered properly from suspend or standby. Need more information on the current recovery behaviour.

Took a few pictures with the Record activity.

Data

quozl-8 coordinates on ladder, WGS84 -31.369688, 148.883629, google maps
quozl-7 coordinates at Mt Naman, WGS 84 -31.37301, 148.95033, google maps

Photographs by Tanya

(740kbyte, contributed, XO appears twice, background changed to ease viewing)

Photographs by XO B4

Facing north, Bluff Mountain on the left, Siding Spring Observatory was visible on the horizon on the right between the two smaller peaks.

Facing west, towards quozl-8 on the ladder, 6.3km away.

Facing east, the peak there is Tonduran Spire, but has had other names

Facing south, tester on left, Tanya and Rob were walkers discovered during the test, Tooraweenah behind them, with the Dilly hills south of Tooraweenah.