Similarly Zigbee channels 20 and 25 suffered error rates of 83% and 61% respectively, in the presence of activity on WiFi 6 / WiFi 11 (considerably worse than the 'interfering' Zigbee channels immediately adjacent to 20 and 25). Also note that the spectrum around the 2.425 GHz is the most used coherently with the fact that ZB15 is the most penalized channel." Yet it is not enough from preventing a heavy interference on ZigBee networks. Such Wi-Fi spectrum is not illegal, since the IEEE 802.11 standard specifies a transmit power reduction of 30 dB for frequencies farther than 11 MHz from the central frequency, and this is indeed achieved. Quoting the article "the spectrum of Wi-Fi devices operating on channel 1 also occupies the 2.425 GHz band employed by ZB15. roughly 50% for Zigbee channel 14 in the same scenario). It found that the assumed 'interference free' Zigbee channels 15, 20, 25 actually suffered much worse error rates if coexisting adjacent to WiFi channels 1, 6, and 11 than the 'interfering' Zigbee channels: for example, observed frame error rates of 89% for Zigbee channel 15 in the presence of WiFi channel 1 (vs.
An interesting complication to the Zigbee/WiFi coexistence issue was raised by a Italian university study of WiFi, Zigbee, and Bluetooth performance in real world situations.