Title: Radio Interface Planning in Mobile Telecommunication
Speaker: Martin Groetcshel, ZIB and TU Berlin 

Abstract:
The frequency spectrum for radio communication is quite limited. Even in the
very early days of wireless communication need was felt to "optimize" the
utilization of the radio spectrum. Graph colouring, e. g., was viewed as an
appropriate mathematical model for frequency assignment. It turned out,
though, that technical side constraints such as channel separation or channel
use restrictions and the desire to minimize interference require more
complicated models. Moreover, any of the transmission techniques, such as
Frequency, Time, or Code Division Multiple Access (FDMA, TDMA, CDMA), that are
currently in use in cellular communication yields different modelling
challenges. 
Today very large and complicated integer or mixed-integer programs are
employed to assign channels to antennas (TRXs) and to determine the antenna
parameters such that the network provides good coverage and the user enjoys
high quality service. In my talk, I will outline, in particular, some of the
approaches that are employed to optimize the radio interface in GSM and UMTS
mobile phone systems. This presentation is based on the work of the
telecommunication research group at the Konrad- Zuse-Zentrum in Berlin.