Diary of Wednesday, 9th February 2005
Prepared by: Barasa Lavina Naliaka
At 9:00am on 9th February 2005 all participants assembled at the The Kastler Lecture Hall, to start the third day of this years's school on Radio-based computer networking.
Prof. E .Pietrosemoli, ULA-EsLaRed-Venezuela, started the day with a lecture on "Mobile Communications". He discussed Personal Communication System requirements, Multiple Access techniques-giving details on Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA) and Code division Multiple Access (CDMA). Prof . Pietrosemoli then looked at Wireless Technologies ,specifically looking at Coding, Equalization, Orthogonal Frequency Division multiple Access (OFDM), Diversity and Diversity combining and Spread Spectrum.
There was a coffee break after which the second lecture of the day commenced at 10:20am.The lecture was on "Basic Antenna Theory" by Prof. Dr. R. Struzak, ITU-BDT, Switzerland, who broadly discussed different aspects on Antennas. He started off the lecture with an interesting mind puzzle: "We use a transmitting antenna to radiate radio waves and a receiving antenna to capture the RF energy carried by the wave..... Somebody told that the receiving antenna also radiates waves during the reception. Is it a true fact or a slip of the tongue? "
Prof .Struzak carried on with discussion on intended and unintended radiators, Antenna purpose, Antenna Functions, a review of basic Antenna types, Radiation pattern, gain, polarization, Equivalent circuit and radiation efficiency and smart antennas.
The lecture was summarized with a Question-Answer session, and then there was a lunch break.
At 2:00pm the participants gathered at the Eklund Laboratory for the lab session: this being the second day. Everyone settled to their respective groups, and then Mr. Carlo Fonda started the laboratory session.
This was basically the continuation of the previous day's laboratory work on measurement of the power and attenuation of the cable and measuring at a given frequency the loss in a cable.
This time round though, each group had to practically do what Mr. Carlo Fonda had demonstrated the previous day.
At the End of the practice, the participants were able to differentiate between the "male" and the "female" N-type connectors and to fix both the connectors to the cable. This was a really interesting lab experience, which was crowned by a quiz.
Each group was required to carry out exercises with Coax Cables, which will be part of the judgment in the final competition.
The exercises involved determination of information for all cables-that is their external diameter, the type of cable, full description of connectors and nominal impedance.
Measuring characteristics of cables like the total cable loss, length and attenuation per unit length unit, characteristic Impedance and Velocity factor.
These exercises are to be practically carried out as group assignments in the laboratory with the supervision of Mr. Carlo Fonda.
Barasa Lavina Naliaka
Department of Computer Science
Tver State Technical University
Russian Federation.