Internet of Things for Architects

IEEE 802.11 spectrum allocation

The first 802.11 protocol used a spectrum in the 2 GHz and 5 GHz ISM region and evenly spaced channels roughly 20 MHz apart from each other. The channel bandwidth was 20 MHz, but later amendments from IEEE allowed 5 MHz and 10 MHz to operate as well. In the United States, 802.11b and g allow for eleven channels (other countries may support up to fourteen). The following figure depicts the channel separation. Three of the channels are non-overlapping (1,6,11):

802.11 2.4GHz frequency space and non-interfering channel combinations. Note the 5 MHz channel separation across 14 channels each 20 MHz wide. 

802.11 ...