Diary of Friday, 25th February 2005

Prepared by: Shree Bhadra Wagle

The day was quite different than the others we had in ICTP classes. We had ,a sort of, expectations & excitations for the activities of this eminent day. As per the schedule, due to the snowfall on the other day, we were eagerly waiting for this final moment of our field activity. We had to experiment on the long distance radio links .

The two sites were chosen as Muggia (~11 Km away from ICTP) and Grado (~27km away). Due to line of sight problem, we chose Galleileo Guest House (GGH) as the site at ICTP end.

Preparation:
In part of preparation of the equipment, tools and other accessories, we had gathered in the lab on the previous evening at 20:00 PM on Thursday. Prof. Ermano , Carlo & Marco gave necessary directions about the Friday's schedule.

And, Prof. Ermano spoke about the preliminary calculations for setting up the link, choice of the antennas at either ends in order to obtain the minimum signal level. The value to minimum receiver signal level was found using the Radio Mobile Software. The software calculates the value with the help of the digital map using the Radio Link Profile by inputting the necessary parameters (distance between the sites, elevation of the sites, Tx. Power, antenna gain of Tx & Rx antennas and the propagation model).

We found the value as -93dBm for GGH- Muggia in order to get a speed of 1 Mbps at 2.4 GHz band and -99 dBm for GGH-Grado for the same speed & frequency using the free space propagation model.

The Journey in the Morning:
We gathered at the bus stop at exactly 09:15 AM and loaded the materials (as we assembled the previous night) from the lab into the Bus. Prof. Ermano, Marco, Rob, Thomas, Steve and all of the participants started for Muggia. Prof. Struzak and Carlo were to handle the jobs at GGH end. We were happy to get to Muggia in about an hour.

Everybody in the bus carried each piece of the materials to the site (it was a Muggia park, like an Observatory point). Some of the groups started fixing the antenna on a big support; some were seen as laying power supply lines. Steve, Rob & Thomas took charge of the little & powerful Metrix Box that was to be used as a client or the access point and their handy laptops.
The GGH end transmitted the signal and we measured the maximum signal level by adjusting the antenna at optimum position. We could easily receive the signal and intercommunicaton between GGH & Muggia end was done using Walki-talkie and cell phones during the session.

Then the signal was fed to the Metrix box to trace it and see other parameters as well. The box could be used as a wireless client to the Access Point with wired access to the internet at the other end. The power level at GGH end was varied and we saw the variations in the signal level at our end. Similarly, we transmitted the radio signal at the 2.4 GHz Band from Muggia to be received at the other end taken after by Carlo. Carlo & Marco seemed to be communicating each other saying ...OK, the level is good .. incresse the power ...decrease it ,OVER.. And so so.).

It was an interesting scene that people were excited to see the measurements and to assist our lecturers for the adventure. But we were as much participating in exploring the Trieste city from the high viewpoint, taking pictures, joking & laughing. Guys were rushing to be included in the picture whenever one would take pose to take pictures. The most exciting moment was that few minutes before leaving the site, it started to snow. It was amazing; Participants were enjoying the snowfall and the extremely cold environment.
Then we carried the accessories back into the bus and headed towards Adriatico for Lunch.

The Adventure at Grado:
Likewise, we entered the bus again at 14:15 to head for Grado, a place across the sea in the west. We reached there within an hour and went up the Hotel Grand Astoria at the terrace. It was our strategic location so that we could have clear line of sight with GGH.
Again the same routine began as in the morning fixing the support, mounting antenna, aligning it and taking measurements.

At this site, we first tried to receive the signal at 5GHz band with a very small dish but we didn't receive enough signal and again measured at 2.4 GHz band with a big reflector & a solid dish. The time was limited and it was approaching sun set; the environment was even more cold though we could see the sun but not the heat out of it. It was very windy, friends were seen as jumping and tightening their dresses to keep them warm. Anyway, it didn't prevent us from taking pictures during the measurements .Again the same scene was repeated, people were rushing in for photographs at different position.
Then, we got into the bus after around 15 minutes walk from the hotel and arrived at adriatico at 7:30PM.

It was really an enthralled and most awaiting experience. Our theoretical concepts, knowledge and few handful of in-lab practice were turned into practical observations on the day. We were all thankful to the ICTP Radio School & its organizers, professors, lecturers.

Shree Bhadra Wagle
Nepal