Building the smart buildings of the future with Wi-Fi HaLow technology

While consumers have embraced the concept of relying on convenient, connected devices to automate home functions, the same is true for smart buildings. Gone are the days of manually setting thermostats or automatic timers. Now, these functions can be controlled from anywhere, anytime, through smartphone apps or even cloud AI. For example, machine learning algorithms can help save energy by identifying low occupancy in specific rooms and shutting down HVAC systems and lighting.

Broadband connections offer ample bandwidth and low latency, but a good wireless connection between the modem and the device has proven difficult to achieve.

This situation continues to this day.

Wi-Fi HaLow technology, named by the W-Fi Alliance, has been standardized by the IEEE 802.11ah task group. Compared with traditional Wi-Fi, Wi-Fi HaLow uses lower frequencies and narrower band channels, the combined effect of which is a wider connection range and lower total energy consumption. Devices can communicate with access points (APs) up to 1 km away, depending on the required application throughput and national regulations on radio systems. For some clean energy systems covering several square kilometers, Wi-Fi HaLow can connect more than 8,000 devices to one access point (AP).   

Figure 1: Wi-Fi HaLow advantages

Although traditional Wi-Fi is the most commonly used wireless communication protocol, the rapid development of the Internet of Things has forced people to rethink Wi-Fi, revealing the technology gap and the role that Wi-Fi needs to play in an all-encompassing connected green world. Many IoT and machine-to-machine (M2M) applications have higher requirements for long-range connectivity and low power consumption, making Wi-Fi HaLow develop at an increasingly faster pace in the future.

Simplify the enterprise access control system architecture

In large commercial buildings, the devices in the security network usually include electric bolt locks, electromagnetic locks, and hybrid smart locks. Other components in the network include external keypads or RFID card scanners outside each door, and exit triggers inside each door, such as passive infrared (PIR) sensors and exit (REX) buttons. 

A typical installation requires connecting a security guard's computer to a control station, which uses a network of wires to control a low-voltage power transformer used to power the lock or change its state. Another approach might use Power over Ethernet (PoE) to provide control signals and power to a gateway controller device up to 100 meters away. Some systems use a hybrid power distribution network with PoE and RS-485 protocols to a dedicated access point near the room, with wireless smart locks at each door.

Wi-Fi HaLow simplifies this device network, reducing not only the cost of infrastructure, but also the cost and time of installation, and reducing the system maintenance costs caused by battery replacement and firmware updates. The standard provides a simplified star topology architecture for connecting high-density sensors and door lock controllers, and can be directly integrated into battery-operated door lock devices without the need for intermediate sub-gateways or proprietary controllers. The network can be as simple as a Wi-Fi HaLow AP, with a PoE cable connected at each layer. Each lock can then be operated as a field-based or cloud-based device.

 Figure 2: Wi-Fi HaLow can reach 10 times the distance, 100 times the area, and 1,000 times the capacity of traditional Wi-Fi and securely connect thousands of devices through a single access point.

Wi-Fi HaLow can also be used as a backhaul network, replacing low-speed cables between the backbone network and the device area. Installing, moving, or changing RS-485 or PoE networks to add functionality requires significant material and labor costs. If a system architect needs to add video or other multi-factor authentication to a wireless door lock, Wi-Fi HaLow has the ability to meet these needs.

Building Automation Systems (BAS)

Wi-Fi HaLow can also improve the efficiency and cost-effectiveness of HVAC systems in commercial buildings. Consider the example of cooling a large office building. This entire network of compressors, sensors, thermostats, and dampers can be networked to provide a deep view of building performance to a building management system (BMS) monitor on-site or in the cloud. Traditional methods of building this network rely on installing wired power and signal connections on most of these components. Some systems contain short-range wireless mesh networks, including 802.15.4 Zigbee or proprietary radios in sensor devices. Several stages of proprietary hubs or gateways add latency, delays, and data throughput limitations on the path from these devices to the Internet BMS.

Compared with these wired and proprietary wireless technologies, Wi-Fi HaLow integrated circuits have unique advantages. Because Wi-Fi HaLow operates in the frequency range below 1 GHz and uses narrowband channels, it can penetrate walls, ceilings, floors and objects more easily than wired or 2.4GHz wireless technologies, so devices can be placed where they are needed with fewer restrictions. This eliminates multiple levels of mesh network connections and repeaters, reducing infrastructure costs and the number of devices that consume energy.

Security and interoperability

Wi-Fi HaLow, like other IEEE 802.11 versions of Wi-Fi, is an inherently secure wireless protocol that supports the latest Wi-Fi certification requirements (WPA3) and AES encryption for over-the-air (OTA) transmissions at data rates that enable secure over-the-air (OTA) firmware upgrades.

Like other types of Wi-Fi, Wi-Fi HaLow is a globally recognized standard (IEEE 802.11ah) that defines how connected devices can authenticate and communicate securely. Device vendors that adopt Wi-Fi HaLow can ensure that their products and networks will interoperate in accordance with the development guidelines of the Wi-Fi Alliance. Because Wi-Fi HaLow is part of the IEEE 802.11 standard, Wi-Fi HaLow networks can also coexist with Wi-Fi 4, Wi-Fi 5, and Wi-Fi 6 networks without affecting their RF performance. 

Traditional Wi-Fi's network congestion, distance limitations, and higher power consumption, as well as the limited number of devices that can connect to a single wireless access point, are no longer viable in the connected world of smart buildings. These limitations hinder new IoT-centric business models that are emerging across industries, which require greater capacity, range, and battery operation while minimizing deployment costs and time.

With the development of Wi-Fi HaLow wireless technology, the concept of removing old lines and installing new ones will become a thing of the past.