By Shahar Feldman, Morse Micro
While consumers have embraced the concept of relying on convenient, internet-connected devices to automate functions within their homes, so too have smart buildings. Gone are the days of manually setting the thermostat or putting lights on mechanical timers. Now these functions can be controlled from anywhere via a smartphone app or even by artificial intelligence (AI) in the cloud. For example, a machine learning algorithm can help save energy by identifying low occupancy in a particular room, thereby turning off the HVAC system and lights.
Broadband service connections provide ample bandwidth and low latency, but a good wireless link between modem and devices has proven elusive.
WiFi HaLow technology, as named by the WiFi Alliance, was standardized by the IEEE 802.11ah task group of the Institute of Electrical and Electronics Engineers. With WiFi HaLow, the combined effects of using lower frequencies and narrower band channels than conventional WiFi, are connections that reach much farther while using less total energy. Devices can communicate with an access point (AP) more than 1 kilometer away, depending on the desired application throughout the country’s regulations on radio systems. For some clean energy systems that span several square kilometers, WiFi HaLow can connect more than 8,000 devices to a single AP.
While conventional WiFi is the most ubiquitous wireless communications protocol in use today, the rapid growth of the Internet of Things (IoT) has forced a rethinking of WiFi, revealed technological gaps and what role it needs to play in an all-encompassing connected and green world. The higher demands for long-range connectivity and low power requirements for many IoT and machine-to-machine (M2M) applications are ushering in WiFi HaLow at an increasingly faster rate this year and for the years ahead.
Simplifying the enterprise access control system architecture
In large-scale commercial buildings, devices in the security network commonly include electronic strikes, magnetic plates, and hybrid smart locks. Other components in this network include external keypads or RFID card scanners outside each door, plus egress triggers on the inside of each door such as PIR (passive infrared) motion detectors or request-to-exit (REX) buttons.The typical installation requires the security agent’s PC to connect to a control station, which uses a network of wires to control the low-voltage power transformers used to energize the locks or change their states. Another method might use Power over Ethernet (PoE) to offer control signals and power to a gateway controller device, up to a maximum distance of 100 meters away. Some systems use a hybrid distribution network of PoE and RS-485 protocol to reach proprietary access points nearby groups of rooms that each have wireless smart locks in the doors.
WiFi HaLow simplifies this network of devices by not only lowering the costs of the security network infrastructure, but also the cost and time of installation, and reduces maintenance costs of the system from battery changes to firmware updates. The standard provides a simplified star-oriented architecture for connecting a high density of sensors and lock controllers and can incorporate directly into battery-operated door lock sets, without the need for intermediary sub-gateways or proprietary controllers. The network can be as simple as a WiFi HaLow AP connected to a single PoE cable on each floor. Each lock is then capable of operating as a premise-based or cloud-based device.
WiFi HaLow can also be used as a backhaul network to replace low-speed cabling between the backbone network and region of devices. There is a significant cost of materials and labor to install, move or change RS-485 or PoE networks to add features. If the system architect needs to add video or other multi-factor authentication to a wireless door lock, WiFi HaLow has the capacity to handle the demands.
Building automation systems
WiFi HaLow can also improve the efficiency and cost of ownership of a commercial building’s HVAC system. Consider the example of cooling the air for a large office building. This entire network of compressors, sensors, thermostats and damper controllers can be networked together to provide a high-level view of the building’s performance to building management system (BMS) monitors on site, or in the cloud. The traditional method for building this network relies on installing wired power and signal connections to most of these components. Some systems incorporate short-reach wireless mesh networks, including 802.15.4 Zigbee or proprietary radios for sensor devices. Several stages of proprietary hubs or gateways add delays, latency and data-throughput restrictions on the path from these devices to reach the BMS on the internet.
WiFi HaLow integrated circuits provide unique advantages over these wired and proprietary wireless technologies. Because WiFi HaLow operates in the sub-1-GHz frequency range using narrow channels, which can penetrate walls, ceilings, floors, and objects much easier than wired of 2.4-GHz wireless technologies, devices can be placed where they are needed, with fewer restrictions. This eliminates multiple stages of mesh connections and repeaters, reducing the infrastructure costs and the number of devices consuming energy.
Secure and interoperable
WiFi HaLow, like other IEEE 802.11 WiFi versions, is an inherently secure wireless protocol. It supports the latest WiFi requirements for authentication (WPA3) and AES (Advanced Encryption Standard) encryption of over-the-air (OTA) traffic, with data rates that enable secure OTA firmware upgrades.
Just like other types of WiFi, HaLow is a globally recognized standard (IEEE 802.11ah) that defines how connected devices authenticate and communicate securely. Equipment vendors using WiFi HaLow have the assurance their products and networks will interoperate by following WiFi Alliance development guidance. Because it is part of the IEEE 802.11 standard, a WiFi HaLow network can also coexist with WiFi 4, WiFi 5, and WiFi 6 networks without impacting their RF performance.
The network congestion, distance limitations and higher power usage of conventional WiFi, along with the limited number of devices that can be connected to a single wireless AP are no longer variable in a connected world of smart buildings. Such limitations impede new IoT-centric business models that are emerging across industries, which require greater capacity, range, and battery operation while minimizing deployment costs and timelines.
With WiFi HaLow wireless technology, the concept of ripping out old wires and putting in new wires may be a thing of the past.
Shahar Feldman is vice president of marketing for Morse Micro.