In homes, work places, coffee shops, campuses and in public places everyone is familiar with WiFi internet access. WiFi has been around for decades . WiFi has evolved from 11Mbps speeds (IEEE 802.11b) to over 1Gbps speeds (IEEE 802.11ac) over this period. The number of users accessing WiFi networks and the demand for higher speeds grown by many folds.
Today primarily WiFi operate in two frequency bands 2.4GHz and 5GHz bands. These bands (Unilicensed bands) are reserved for WiFi use internationally without a license. A body called “WiFi alliance" create certification program for all WiFi devices. Devices certified as 802.11b/g/n that device operate in 2.4GHz band. Devices certified as 802.11a/b/g/n/ac may operate in both frequency band. However some devices operate only in one frequency band at a time. Therefore it is important to know if the WiFi device operate in “concurrent dual-band" mode.