Low-power Wi-Fi HaLow radio ready for IoT
The Wi-Fi HaLow™ radio can be used 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’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/s to 7.8 Mb/s. 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 a sub-1GHz IEEE 802.11ah transceiver from imec and Holst Centre, and a Medium Access Controller (MAC) hardware and software IP and application layer from Methods2Business 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 7.1mW in Tx mode for 0 dBm output power.
Methods2Business 802.11ah MAC core implements all the new Wi-Fi HaLow™ functionality to address the drawbacks of traditional Wi-Fi in IoT. Besides mandatory features for connecting up to 8.000 IoT clients (Hierarchical AID), improving collision avoidance in channel access mechanisms (CSMA/CA, DCF, EDCA), and increasing throughput by supporting shorter MAC headers, very advanced power saving modes like Target Wake Time (TWT) and Restricted Access Window (RAW) are also supported. To further trade-off power versus performance, time-critical functions are implemented in hardware while higher level MAC protocols are realized in software.