The internet has now become a necessity of modern life and Wi-Fi serves as a crucial enabler for communication. As our connectivity requirements have changed, Wi-Fi technology has continuously advanced to meet new demands. In keeping with this trend, the Internet of Things (IoT) environment is evolving rapidly and Wi-Fi HaLow is designed to meet its long-range and low-power connectivity needs.
In this blog, we describe the evolution of Wi-Fi HaLow and the protocols governing it, expanding upon how Wi-Fi HaLow is suitable for IoT devices, and providing a comparison between Wi-Fi HaLow and selected low power wide area (LPWA) technologies.
Subscribers to Transforma Insights advisory service can learn about Wi-Fi HaLow in more detail in our recent report: Wi-Fi HaLow: Significant potential to support long-range and low-powered IoT applications.
Wi-Fi was first introduced in 1997 and since then it has evolved significantly, with data rates increasing from 1-2 Mbps to 9.6 Gbps in Wi-Fi 6. Wi-Fi 1 operated at 2.4GHz with speeds up to 11 Mbps, while Wi-Fi 2 moved to 5GHz, achieving 54 Mbps but lacked market traction due to high costs and non-compatibility. Wi-Fi 3 returned to 2.4GHz with similar speeds. Wi-Fi 4, launched in 2009, introducing dual-band support (2.4/5GHz) and boosting speeds to 600 Mbps. Eventually, in 2017, the IEEE formed a task group and established the 802.11ah protocol, which is now popularly known as Wi-Fi HaLow. This was primarily done due to the increasing adoption of smart devices (which often operate for multiple years and typically send small amounts of data) by various industries.
Wi-Fi HaLow employs multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) to enhance network performance. This technology uses multiple transmitter and receiver antennas to transmit data streams simultaneously, improving signal quality. It also divides an allocated frequency band into subcarriers to maximise the usage of available frequency. Additionally, Wi-Fi HaLow also integrates Forward Error Correction (FEC), which adds redundant error correction codes before transmission to enhance data reliability. Combined, these two technologies reduce signal loss and improve data transmission and reception efficiency.
Simply put, the purposes of previous generations of Wi-Fi and Wi-Fi HaLow are different. While earlier Wi-Fi protocols mainly operated in 2.4GHz and 5GHz and were more focused on offering high bandwidth and targeted low latency applications to cover a small geographic area (often less than 100 metres), Wi-Fi HaLow works in licence-exempt sub-1GHz frequency bands and supports much longer-range connections albeit with lower bandwidth. This implies that a lesser number of access points (APs) are required in Wi-Fi HaLow, since each can serve a large number of IoT devices (up to 8,191) over an extended area. This, in turn, reduces network infrastructure cost significantly.
As mentioned earlier, Wi-Fi HaLow is a better alternative in Wi-Fi standards for many IoT devices, since it offers numerous benefits which are as follows:
Wi-Fi HaLow's lower frequency band and reduced channel bandwidth allow signals to travel farther than traditional 2.4GHz Wi-Fi. Designed for ranges up to 1 km, tests have shown it can achieve 2 Mbps throughput at distances up to 16 km.
The sub-1GHz frequency band offers superior penetration through obstacles like trees, buildings, and other signal barriers compared to the 2.4GHz and higher frequency bands associated with other Wi-Fi standards. This can be attributed to reduced signal path attenuation at lower frequencies.
Wi-Fi HaLow's energy-saving features, such as Target Wake Time (TWT) and Restricted Access Window (RAW), enable devices to consume less power, extending battery life to several years.
The 2.4GHz band often faces congestion due to different wireless technologies like Wi-Fi, Zigbee, and Bluetooth, with only three non-overlapping channels available in Wi-Fi. In contrast, Wi-Fi HaLow operates in less crowded sub-1GHz bands, offering 26 non-overlapping 1MHz channels. This reduces interference and supports the connection of thousands of devices simultaneously.
Wi-Fi HaLow supports WPA3 and Enhanced Open, based on Opportunistic Wireless Encryption (OWE), the highest wireless security standards in wireless network technologies and offering a high level of encryption. OWE provides the necessary privacy in public environments in which connected devices access cloud servers.
This section of the blog compares the key features of Wi-Fi HaLow with a range of LPWA technologies including LoRa, LTE-M, NB-IoT and Sigfox which are also intended to support long-range IoT connections whilst also enabling long battery life.
Wi-Fi HaLow offers far better data range capability compared to other Wi-Fi standards, but still falls behind in range compared to the LPWA standards. Compared to 2.4GHz and 5GHz frequency bands used by other Wi-Fi standards, Wi-Fi HaLow offers superior wall penetration and signal range due to operation at the sub-1GHz frequency band.
The Wi-Fi Alliance claims that Wi-Fi HaLow can achieve data rates ranging from 150Kbps to 86.7Mbps, depending on the deployment environment, far higher than any of today’s LPWA technologies.
Wi-Fi HaLow is considered to be a good option for energy savings since it has a short transmission time. According to the Wi-Fi Alliance, Wi-Fi HaLow can transmit 22.4 kilobits per Joule in comparison to NB-IoT’s 3.7 kilobits per Joule, resulting in extended and much better lifetime of Wi-Fi HaLow connected device batteries in certain circumstances.
Wi-Fi HaLow supports data rates of around 150kbps to 15Mbps and can offer far lower latency to serve applications that require real-time responses.
Wi-Fi HaLow chipsets are currently a bit more expensive (compared to Sigfox and LoRaWAN), typically costing more than USD20. The chipset costs of Wi-Fi HaLow, in particular, are likely to fall with increasing volumes.
Summing up:
Based on our research, it is clear that Wi-Fi HaLow's versatility will make it a preferred choice for a growing number of IoT projects. Its ability to deliver reliable long-range connectivity, high data throughput, support for dense device networks, and low-power consumption positions it as a standout solution in the IoT space for certain applications. Moreover, its cost-effectiveness adds to its appeal, enabling efficient deployment across diverse applications. As adoption accelerates, Wi-Fi HaLow will solidify its position as a viable wireless standard in the evolving IoT landscape.
