16 Mar 2021


Wi-Fi (IEEE 802.11) is a short range wireless technology that enables data exchange or internet connectivity over the unlicensed 2.4 GHz and 5 GHz bands.

Wireless connectivity with LAN infrastructure

Wi Fi is the preferred short range wireless technology to connect to LAN infrastructure and to achieve high data rates. It is well suited for video streaming, monitoring, and data acquisition, but can also be used for time critical control. Further, the built in roaming functionality is useful in factory automation applications with moving devices.

The IEEE 802.11 specifications have evolved over the years to cover an increasing number of capabilities. With a larger bandwidth, new modulations, and MIMO (multiple input, multiple output) technologies, higher data throughputs (and new applications) have been achieved. For instance, IEEE 802.11ac was released in December 2013 to enable high quality video streaming to several devices, which is useful in applications such as in car infotainment systems. In addition to the evolving radio specific capabilities, new specifications have been designed that focus on topics including increased security features, network management, and improved roaming.

The latest addition is IEEE 802.11ax, named Wi-Fi 6 by the Wi-Fi Alliance. It adds three main features: higher data rate, increased efficiency in high density networks (many devices), and lower power for IoT devices.

Dual-band Wi-Fi

Most Wi Fi devices, as well as other wireless technologies such as Bluetooth or ZigBee, operate in the 2.4 GHz band. As a result, this band easily becomes crowded, especially in urban environments. IEEE 802.11b and 802.11g radios use the 2.4GHz frequency band while IEEE 802.11a and 802.11ac radios communicate over the 5 GHz frequency band. IEEE 802.11n radios as well as the new IEEE 802.11ax radios can operate in either frequency band.

LTE co-existence

Wi Fi and LTE often co exist in the same device. Simultaneous operation of these radios in adjacent frequency bands causes interference that can degrade performance and throughput. To optimize performance some u blox modules employ a filter to protect the Wi Fi radio from interfering signals.