As the scope of the city's business functions is very broad, the Cross-cutting Group focuses its scientific activities on the functions of the urban metabolism and the trades that perform these functions: water supply | sewerage purification sewage | garbage removal cleaning sweeping | sorting and waste treatment | energy distribution (gas, electricity, district heating) | telecom networks (cable, fiber optic, wireless video surveillance) | traffic control (regulation) parking | parks and gardens green spaces, etc .....