Reliable wireless transmission in systems with many sensors - the extremely short telegrams of EnOcean wireless modules enable operation of a large number of transmitters all in the same cell. Any error rate caused by telegram collisions remains extremely low. Ex-pressed in statistics, transmission reliability is still better than 99.99% for 100 wireless sensors each transmitting their data once a minute. In other words, even large office buildings or extensive industrial plants can be equipped with high numbers of EnOcean sensors, and all operating simultaneously.