Low-power Wi-Fi HaLow radio design for IoT applications

June 06, 2016 // By Graham Prophet
Belgian nanoelectronics research center imec, the associated Holst Centre and Wi-Fi IP provider Methods2Bussiness (Eindhoven, The Netherlands) have collaborated on a complete Wi-Fi HaLow radio solution; the low-power, long-range radio link uses 10 times less power than state-of-the-art orthogonal frequency division multiplexing (OFDM) radios.

The design will be applicable, say the partners, for a broad range of applications related to the Internet of Things (IoT) and complies with the most recent wireless networking protocol, IEEE 802.11ah.


The radio solution’s compliance with the recently amended wireless networking protocol ensures that it is especially optimized for IoT-related applications. The Wi-Fi Alliance recently introduced the HaLow designation for the new low-power, long-range Wi-Fi protocol IEEE802.11ah. Compared to other IoT standards, its sub-GHz carrier frequency and mandatory modes with 1 MHz/2 MHz channel bandwidths allow devices to operate over a longer range with scalable data rates from 150 kb/sec to 7.8 Mb/sec. The standard uses OFDM to improve the link robustness against fading, which is important in urban environments, and to achieve a high spectral efficiency (data rate over a given bandwidth).


The radio integrates imec and Holst Centre’s sub-1GHz IEEE 802.11ah transceiver and Methods2Business’ Medium Access Controller (MAC) hardware and software IP and application layer to enable 802.11ah communication between large numbers of IoT clients and the internet using a central access point. The transceiver comprises a complete low-power physical layer implementation of RF front-end and digital baseband. It features a 1.3nJ/b fully digital polar transmitter optimized for IoT applications as well as for the novel IEEE 802.11ah Wi-Fi protocol. The transmitter surpasses the tight spectral mask and error-vector-magnitude (EVM) requirements of conventional Wi-Fi standards. It does so while demonstrating a power consumption rate as low as 7.1 mW in Tx mode for 0 dBm output power.