2.4Ghz was a ISM junk band long before domestic microwave ovens arrived. In fact 2.4Ghz was used for microwave ovens specifically because it was an ISM band, an

2.4Ghz was a ISM junk band long before domestic microwave ovens arrived. In fact 2.4Ghz was used for microwave ovens specifically because it was an ISM band, and therefore was available.