An antenna switching system includes a first antenna, a second antenna, a first sensing unit, a second sensing unit, a controlling unit, and a switching unit. The invention also relates to a method for heating the gas. Further, the invention relates to a gene library prepared from an enriched environmental pool of organisms enriched in DNA encoding a polypeptide with an activity of interest. Furthermore, the method is performed at near room temperature, which provides more flexibility in the manufacturing process. A control signal indicating disturbance-free reception of data is transmitted to the transmitter if the time between successive light pulses does not exceed a predetermined maximum time interval.