Advantages of WiFi HaLow | disadvantages of WiFi HaLow, 802.11ah
This page covers advantages and disadvantages of WiFi HaLow (IEEE 802.11ah). It mentions benefits or advantages of WiFi HaLow and drawbacks or disadvantages of WiFi HaLow.
What is WiFi HaLow (IEEE 802.11ah) ?
Traditional wifi standards are not preferable for IoT applications due to high power consumption and larger frame overhead. Hence WiFi Alliance has developed WiFi HaLow which supports lower power consumption and longer range of operation. It is defined in IEEE 802.11ah.
IEEE 802.11ah operates in sub GHz band (i.e. 900 MHz). It has different PHY and MAC layer designs and hence 802.11ah hardware is more power efficient than its predecessor.
Following are the technical features of WiFi HaLow as defined in 802.11ah standard.
• Frequency Band: 900 MHz (US), 850 MHz (Europe), 700 MHz (China)
• Bandwidth: 1, 2, 4, 8, 16 MHz
• Modulation type: BPSK to 256 QAM
• Channel Architecture: SC, OFDM
• Maximum Data Rate: 40 Mbps
• Coverage range: About 1 Km
• Max. transmit power: 100 mWatt
• Security : WPA
Refer WiFi HaLow basics which describes functions of PHY and MAC layer defined in IEEE 802.11ah.
Benefits or advantages of WiFi HaLow
Following are the benefits or advantages of WiFi HaLow:
➨It consumes less power than traditional wifi device. Hence wifi HaLow devices with coin cell battery work for months or years.
➨It offers longer coverage range which is about 1 Km. This is almost twice that of traditional wifi.
➨The WiFi HaLow signal can easily penetrate through walls and other obstacles as it is lower in value compare to high frequency (2.4 GHz/5 GHz) used by traditional wifi network.
➨It does not require any proprietary hubs or gateways.
➨It offers reliable wireless link due to use of less congested frequency band, higher sensitivity and link margin.
➨WiFi HaLow is ideal for short and bursty data used for IoT (Internet of Things) which does not consume more power and requires to travel longer distances. This is useful for smart building applications such as smart lighting, smart security, smart parking, smart city, smart HVAC etc.
➨MAC layer is designed to support thousands of connected devices. WiFi HaLow can support up to 8191 devices with single AP (Access Point).
➨It is used for cellular traffic offloading due to its outdoor extended range.
➨Sub-GHz frequency used in 802.11h suffers from lower interference compare to 2.4 GHz band.
Drawbacks or disadvantages of WiFi HaLow
Following are the drawbacks or disadvantages of WiFi HaLow:
➨There is no global standard for 900 MHz band unlike 2.4 GHz used everywhere in the world. Moreover WiFi HaLow is US centric.
➨Antennas in sub-GHz range are larger compare to 2.4 GHz WiFi system.