Wi-Fi HaLow - The Latest Wireless Standard for IoT Applications

April 30, 2021
Wi-Fi HaLow

Wi-Fi HaLow – The Latest Wireless Standard for IoT Applications

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Wi-Fi HaLow (IEEE 802.11ah) is the latest wireless standard designed specifically to address the major challenges of IoT (Internet of Things) applications. HaLow has a very effective and efficient ability to operate on very low power and at longer ranges than any Wi-Fi, and penetrate through

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Wi-Fi HaLow (IEEE 802.11ah) is the latest wireless standard designed specifically to address the major challenges of IoT (Internet of Things) applications. HaLow has a very effective and efficient ability to operate on very low power and at longer ranges than any Wi-Fi, and penetrate through walls that are well suited to meet the unique needs of the smart home, industrial markets, and smart city. Due to the less power consumption Wi-Fi HaLow can extend the versatility and application of traditional Wi-Fi networks to a much larger scale including but not limited to the small battery-operated wearable devices, factory automation, IoT/IIoT (Industrial IoT) devices.

Advantages of developing IoT solution with Wi-Fi HaLow

WiFi HaLow is pretty close to being the IoT wireless standard offering the best combination of power consumption, range, throughput, and deployment costs. Let’s have a look at each one of them in detail:

  • Low Power Consumption: Wi-Fi HaLow has comparatively increased the energy efficiency over other low-power LAN/WAN technologies. The effective power saving leads to a multi-year battery operation. As power operation requirement is low, the coin cell battery operation supports less current consumption
  • Long Range and Robustness: The narrowband signals (Sub-1 GHz) travel farther using less energy compared to 2.4 GHz signals, therefore, providing the longer range. It also provides a minimum 10 dB link budget advantage over 2.4 GHz Wi-Fi and more than 1 km reach can be achieved for higher amplified connections with associated design
  • IP Networking Capability: As Wi-Fi HaLow is complying with IEEE 802.11ah international standard, it has native IP support and does not require further conversion gateways. The high data throughput supports UDP, TCP/IP, and IP-based discovery protocols
  • Data Rates and Security: According to Wi-Fi Alliance, the measured support data is 150 kbps to 86.7 Mbps, and the latest security standards are supported as per other Wi-Fi technologies like Wi-Fi certified WPA3, Wi-Fi certified enhance open based on Opportunistic Wireless Encryption (OWE), and also provide support for Wi-Fi Easy Connect
  • Cost-Effectiveness: As Wi-Fi HaLow is an unlicensed spectrum operation, no additional subscription fees are required. Proving to be cost-effective, the support will be provided to both, the private and controlled networks, over-the-air firmware upgrades enable and simplifies infrastructure without the need for complex meshes or repeaters
  • Device Capacity and Network Integration: Wi-Fi HaLow supports 8,191 devices per SSID based on the associate conditions. The native IP networking, including internet protocol version 6 (IPv6) also provides support and does not require any gateways or conversion boxes that do not interfere with pre-existing networks. Also, Wi-Fi HaLow can easily integrate with Wi-Fi network APs

Key aspects of Wi-Fi HaLow

RF Technologies Comparative Analysis with respect to Wi-Fi HaLow

Attributes Wi-Fi HaLow Bluetooth Low Energy Z-Wave Zigbee LoRaWAN NB-IoT
Frequency Sub-1 GHz 2.4 GHz Sub-1 GHz 2.4 GHz / Sub-1 GHz Sub-1 GHz Licensed
Data Rate (bps) 150 k – 86.7 M 125 k – 2 M 9.6 k – 100 k 250 k 300 – 27 k 20 k – 127 k
Range (m) > 1 k < 100 < 30 < 20 < 10 k < 10 k
Modulation OFDM over BPSK, QPSK, 16/64/256 QAM GFSK GFSK BPAK/OQPSK CSS QPSK
Security WPA3 128-bit AES in CCMode Security 2 (S2) 128-bit AES in CCMode 128-bit AES in CCMode 3GPP security
Network Topology Star/Relays P2P/Mesh Mesh Mesh Star Star
Open Standard IEEE 802.11ah Bluetooth SIG Proprietary IEEE 802.15.4 Proprietary 3GPP LTE Cat- NB1/NB2

The requirement of the Wi-Fi HaLow network discloses that the part of the sub-1 GHz band used by Wi-Fi HaLow varies by market according to regulatory requirements like:

  • United States: 902 MHz to 928 MHz
  • Australia and New Zealand: 915 MHz to 928 MHz
  • Europe: 7 MHz of spectrum split among the 800 MHz band and 900 MHz bands

Product manufacturers should consult their local regulatory entity to determine which portion of the sub-1 GHz band is approved for use. Wi-Fi Alliance actively promotes spectrum for Wi-Fi HaLow from 915 MHz to 925 MHz range to support product development for worldwide deployment.

Critical Power Saving Feature of Wi-Fi HaLow

One of the key design criteria for Wi-Fi HaLow technology is low power consumption to enable battery-powered IoT devices to operate for multiple years. The new MAC layer functionality enables devices in a Wi-Fi HaLow network to save energy, reduce congestion, and increase both capacity and device density. Transmitting a radio signal typically consumes more power than receiving a signal. Any reduction in transmissions for a device will usually save energy. The key factor for low power consumption is to ensure that the radio can reliably stay asleep a long period of time without being dropped or disassociated by the AP (Access Point). By allowing Wi-Fi devices to spend more time sleeping, the average energy consumption for such devices is greatly reduced. Devices that are asleep or passively listening will free up the available spectrum for active client devices to transmit their data.

Importance of Wi-Fi HaLow

Let us understand the Wi-Fi HaLow features that enable efficiency and energy savings in detail:

  • Non-Traffic Indication Map (TIM) Mode Options: In some wireless local area networks (WLANs), the devices must wake frequently to monitor and respond to the Traffic Indication Map (TIM) sent by the AP in beacon frames multiple times per second. The TIM is used to indicate which client devices should expect inbound data. Wi-Fi HaLow devices can save power by operating in optional non-TIM modes, where they do not have to stay awake to actively monitor the beacon frames. This feature removes the need for a Wi-Fi client device to periodically check beacon messages. Freeing Wi-Fi HaLow from TIM mode allows it to conserve energy, making it competitive with other IoT sensor network technologies. A non-TIM mode is an option that depends upon the desired function of the devices and network. TIM mode is also supported by Wi-Fi HaLow. A Wi-Fi HaLow AP can support both options concurrently for a mix of devices
  • Target Wake Time (TWT): Client devices that expect to sleep for a long period of time can negotiate a TWT contract with the AP. The AP maintains any traffic destined for the client until the agreed-upon wake time is reached. When the client device wakes at the prescribed time, it listens for its beacon and engages the AP to receive and transmit any data required before returning to its sleep state. The interval between wake times, negotiated by the client and AP, can vary from especially short (microseconds) to very long (years)
  • Restricted Access Window (RAW): RAW is another planning method when groups of client devices are allowed to communicate. For systems with predictable activity periods, an AP can grant a subset of clients with RAW privileges to transfer their data, while others can be forced to sleep, buffer non-urgent data, or both. The client devices save power and leave more network capacity available for other time-critical traffic

About VOLANSYS

VOLANSYS being a one-stop solution provider company, designs and develops complete IoT solutions. Our vast experience in Wi-Fi technology, considering the latest, makes it possible for our clients to have a leading edge in their very competitive market. To understand in detail, read our success stories, giving overview of how VOLANSYS helped their client in developing a Wi-Fi-based IoT solution.

Also, read the latest blog on the impact of Wi-Fi 6 on Industrial IoT, therefore, delivers better reliability with the greatest security and resolves the connectivity issue between multiple devices.

Pratik savle

About the Author: Pratik Savle

Pratik is working as an Associate Firmware Engineer at VOLANSYS Technologies having 2.6 years of experience. He is a passionate solution provider and has experience in development and troubleshooting for various Wired and Wireless Protocols, and Linux and RTOS application development.