While conventional Wi-Fi is the most ubiquitous wireless communications protocol in use today, the rapid growth of the IoT has forced a rethinking of Wi-Fi, revealing technological gaps and what role it needs to play in an all-encompassing connected world. The higher demands for long-range connectivity and low power requirements for many IoT and machine-to-machine (M2M) applications are ushering in 802.11ah Wi-Fi HaLow at an increasingly faster rate this year and for the years ahead.
Wi-Fi HaLow technology was standardized by the IEEE 802.11ah task group and received its name by the Wi-Fi Alliance (WFA). It operates in the unlicensed sub-1 gigahertz (GHz) frequency spectrum band and offers data rates varying from hundreds of kbits/s to tens of Mbits/s and across distances of tens of meters to over a kilometer. Wi-Fi HaLow satisfies the scalability, robustness, and security demands required to address the most challenging IoT environments.
So what makes Wi-Fi HaLow the ideal wireless technology to support the IoT? Below are 10 key reasons how Wi-Fi HaLow is solving the fundamental weaknesses of existing wireless technologies.
- Energy efficiency
The 802.11ah Wi-Fi HaLow protocols promote conservation of energy for devices that can sleep for long periods of time. This enables the widest range of power options from a small battery for short reach applications to larger battery, higher-power devices that reach beyond 1 km.
Orthogonal frequency-division multiplexing (OFDM) with advanced modulation and coding schemes offers higher throughput with data rates that adapt to the channel conditions. The higher the throughput, the shorter the message travel airtime is, which means that the radio can go back to sleep quicker, conserving energy. WLAN’s listen-before-talk protocol means less contentions on the media and less energy wasted on retransmission of packets.
Wi-Fi HaLow idle and sleep modes, combined with Morse Micro’s proprietary circuit design techniques, allows for the transfer of more bits per unit of energy and lower idle power consumption to rival other technologies.
- Data rate
Wi-Fi HaLow offers the widest range of data rates to suit IoT applications such as high-definition video cameras streaming tens of Mbits/s to lower bit-rate applications such as temperature sensors, door locks, or mailboxes. Rates can automatically scale for changes in conditions or distance from an access point (AP), just like Wi-Fi.
Delivering 1 meter to >1 km, sub-1 GHz narrow band signals, Wi-Fi HaLow covers a wider range of applications from smart homes to large warehouses, without repeaters or meshes. The narrow band signals reach 10× range, 100× the area or 1000× the volume of traditional 2.4 GHz Wi-Fi or Bluetooth and even higher for shorter range 5 GHz Wi-Fi 5/6 (802.11ac/ax) and 6 GHz Wi-Fi 6E (802.11ax) (Figure 1).
Figure 1: Wi-Fi HaLow – reaching 1000× the volume of traditional Wi-Fi. (Source: Morse Micro)
- Penetration through material
The physics are simple, the lower the frequency, the better the penetration (free-space propagation losses are lower) (Figure 2). Wi-Fi HaLow uses the 750 MHz – 950 MHz spectrum, which is 2.5× lower than the 2.4-GHz Bluetooth, Wi-Fi 4 or Zigbee, 5× lower than 5-GHz Wi-Fi 5 and 6× lower than 6-GHz Wi-Fi 6e. Variability of construction materials and layouts of homes and buildings has less effect on HaLow signals.
Figure 2: Wi-Fi HaLow offers superior range and penetration through material. (Source: Morse Micro)
Wi-Fi HaLow requires the most advanced WPA3 security for authentication and encryption of data. Morse Micro supports existing WPA3 and future improvements in Wi-Fi security (Figure 3). Higher data rates of Wi-Fi HaLow enable fast over-the-air (OTA) firmware updates, which many long-range wireless technologies like LoRa or Sigfox cannot accomplish without taking devices offline for long periods of time.
Figure 3: Wi-Fi HaLow adopted the most advanced WPA3 security protocol and supports over-the-air security upgrade so networks are kept uncompromised. (Image: Morse Micro)
- Network data capacity
Wi-Fi HaLow specifies a wide range of data rates for up to 8,191 devices per AP (Figure 4). Multiple signaling options reduce overhead required to manage and control larger amounts of devices. One such example is the restricted access window (RAW), a unique feature for HaLow, which allows an AP to grant privileges to a subset of stations to transfer their data while others are forced to sleep, buffer non-urgent data, or both. This reduces collisions and frees up airwaves for active devices to transfer more data at the fastest modulation and coding schemes (MCS) rates they can achieve.
Figure 4: A single Wi-Fi HaLow access point can address thousands of devices. (Image: Morse Micro)
- Installation/operational costs
Wi-Fi HaLow supports native IP traffic, just like traditional Wi-Fi. Simple installation requires only a Wi-Fi HaLow capable AP or router. No proprietary hubs or gateways are needed. The star-oriented architecture does not require complex meshes of repeaters that bog down messages and cause management problems for other wireless technologies. It uses license-free sub-1 GHz spectrum with no recurring subscription fees or data plans needed with cellular network providers.
- License-free spectrum
A service provider contract is not required since Wi-Fi HaLow does not rely on mobile service providers. Like traditional Wi-Fi, customers own their equipment and use license-free radio spectrum. The wireless technology operates in the license-exempt frequency bands worldwide, ranging from 750 MHz to 950 MHz. It does not use the frequencies of cellular data carriers that usually absorb the cost of license fees and subscriptions. Certain restrictions of use may apply and may vary by country.
- Interoperability & customer experience
Wi-Fi HaLow is a globally recognized standard which defines how devices communicate. Much like previous generations of Wi-Fi, Wi-Fi HaLow equipment vendors ensure interoperability by following the guidance of the Wi-Fi Alliance, which provides specifications and certification services to members. Other wireless IoT technologies are either proprietary, or do not have as well-organized guidance which may impact time to market, product costs, and customer experience.
Users will experience the same ease of use as traditional Wi-Fi networks. Add to that the simplicity of Wi-Fi HaLow’s single AP solutions, offering higher out-of-box installation success and eliminating the complexity and challenges of alternative mesh network deployments.
- Native IP support
Native support for IP traffic is defined in Wi-Fi HaLow much like traditional Wi-Fi. Using a Wi-Fi HaLow capable router, all client devices can use IPv4/IPv6 transport protocols for direct access to the internet for cloud-based services and management of IoT data. Other wireless IoT technologies such as Bluetooth, Zigbee, Z-Wave, LoRa, and Sigfox require a proprietary gateway to convert all local client traffic to IP traffic for internet access. These additional stages of packet processing are required to wrap extra data around the packets, adding delays and reducing efficiency of their networks.
In the initial stage of deployment, Wi-Fi HaLow is expected to be used in both indoor and outdoor applications where standard Wi-Fi cannot reach as in the case of battery-operated surveillance systems, wireless cameras, and doorbells. Another typical use case would be large venues, where a single HaLow access point can substitute for a large number of APs, obviating inefficient, complex mesh architectures, simplifying installation, and reducing total cost of ownership.
Industrial automation, process control sensors, building automation, warehouses, and retail stores amongst many others will need this technology, enabling everything to remain connected in an increasingly automated world. Indeed, Wi-Fi HaLow stands out for its versatility.