Aouda wireless network subsystem test successful!

7. Feb 2009

The Aouda simulated spacesuit system saw its first successful subsystem test. Designed and programmed by Georg Gramelt, the system is comprised of two Triotronix routers using a MikroTik RouterOS -software package with a 1m omnidirectional antenna for the suit to be mounted ontop of the personal life support system and a 120° directional wireless network antenna optimized for 5 Ghz.

Impressions from Comm Test

The complete system was tested in a medium (> 2km) range communication test performed by Olivia and Christian Haider and Aouda project manager Gernot Groemer in western Tyrol. Based upon Google Earth datasets, a location for the suit-component was choosen in the Inn-valley near Schoenwies where the surrounding mountains provided an excellent elevated transmitting location. The tests were carried out under direct line-of-sight conditions. A clear ping was archieved at a distance of 2900 m, but this turned out not to be sufficient for bandwidth measurements, so the distance between mobile and base station was reduced to 1400m. The bandwidth archieved under these test conditions was between 15 Mbps whilst simoultanously transmitting and receiving (both components in a few meters distance) and 5 Mbps (1400 m). "Although these distances do not meet yet the final requirement of archieving several kilometers of range", Georg Gramelt, who is coordinating the WLan-subsystem development, commented after the tests, "however, we have still a few adjustments to make to boost the capacity of Aouda which is currently operating at a power output of 500 mW. For the development of the prototype, this is by far enough." Short range tests (<100 m) showed that the near-field communication bandwidth is not very much dependent on antenna orientation and even houses (blocking the direct line of sight) are not an obstacle to a high bandwith. Hence, the robustness of the WLan-subsystem is high enough to give a "GO"-decision for the implementation into the suit system. In the meantime, Harald Fauland and Georg Gramelt are both working on the analogue back-up radio system in the 4m band. "Just in case everything else fails in the suit, even the main power source, or the On-Board Data Handling systems crushes, or we are loosing the relay signal etc..., we still want to have a safety margin by using analogue radio technology with a proven communication range of several dozen kilometers" adds project manager Gernot Groemer, " following our so-called PolAres 3S-principle: Safety-Science-Simulation."