802.11ah Channels

What frequency band does 802.11ah operate in?

802.11ah operates in the sub-1 GHz license-exempt frequency bands, typically around 900 MHz.

Why does 802.11ah use sub-1 GHz bands instead of 2.4 GHz or 5 GHz?

Sub-1 GHz offers better range and penetration through obstacles, ideal for IoT and sensor networks.

How many channels does 802.11ah support?

It supports up to 26 channels depending on the regulatory domain and channel bandwidth.

What channel bandwidths are available in 802.11ah?

Channel bandwidths include 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz.

What is the benefit of using narrower channel widths in 802.11ah?

Narrower channels improve range and reduce power consumption at the cost of lower data rates.

Are 802.11ah channels overlapping or non-overlapping?

Channels can be both; careful channel planning is required to minimize interference.

What is Dynamic Frequency Selection (DFS) in 802.11ah?

DFS allows the device to avoid interference by switching channels when radar or other signals are detected.

Does 802.11ah support channel bonding?

No, 802.11ah generally uses narrow channels and does not support channel bonding like 802.11ac.

How does channel selection impact 802.11ah network performance?

Selecting less congested channels reduces interference and improves range and throughput.

Can 802.11ah devices coexist with other sub-1 GHz devices?

Yes, but coexistence mechanisms and careful channel planning are necessary to minimize interference.

Are 802.11ah channels fixed or can they be dynamically allocated?

Channels are typically fixed by regulation but devices can dynamically switch channels for interference mitigation.

What regulations affect 802.11ah channel usage?

Regulations vary by country but generally limit power and frequency ranges in the sub-1 GHz bands.

How does the low frequency band benefit IoT applications in 802.11ah?

It offers extended range and better wall penetration for sensor networks and smart metering.

What is the impact of channel bandwidth on data rate in 802.11ah?

Wider bandwidth channels provide higher data rates but shorter range and more power consumption.

Can 802.11ah channels be used globally?

Channel availability varies globally due to differing regional regulations.

How is interference handled between adjacent 802.11ah channels?

Through proper channel spacing, listen-before-talk mechanisms, and dynamic channel switching.

Do 802.11ah devices support channel hopping?

Yes, channel hopping is used to improve reliability and coexistence in congested environments.

What is the maximum transmit power allowed on 802.11ah channels?

Transmit power is limited by regional regulations, typically between 10 mW and 1 W.

How does 802.11ah channel planning differ from traditional Wi-Fi?

It focuses on long-range, low power IoT use cases using narrowband channels in sub-1 GHz bands instead of crowded 2.4/5 GHz bands.

Topics in this section,

Channel Number (MHz)

Center Frequency (MHz)

Frequency Range (MHz)

DFS Required

1

902.3

901.8 – 902.8

No

2

903.1

902.6 – 903.6

No

3

903.9

903.4 – 904.4

No

4

904.7

904.2 – 905.2

No

5

905.5

905.0 – 906.0

No

6

906.3

905.8 – 906.8

No

7

907.1

906.6 – 907.6

No

8

907.9

907.4 – 908.4

No

9

908.7

908.2 – 909.2

No

10

909.5

909.0 – 910.0

No

11

910.3

909.8 – 910.8

No

12

911.1

910.6 – 911.6

No

13

911.9

911.4 – 912.4

No

14

912.7

912.2 – 913.2

No

15

913.5

913.0 – 914.0

No

16

914.3

913.8 – 914.8

No

17

915.1

914.6 – 915.6

No

18

915.9

915.4 – 916.4

No

19

916.7

916.2 – 917.2

No

20

917.5

917.0 – 918.0

No

21

918.3

917.8 – 918.8

No

22

919.1

918.6 – 919.6

No

23

919.9

919.4 – 920.4

No

24

920.7

920.2 – 921.2

No

25

921.5

921.0 – 922.0

No

26

922.3

921.8 – 922.8

No

Channel Number (MHz)

Center Frequency (MHz)

Frequency Range (MHz)

DFS Required

1

863

862 – 864

No

2

864

863 – 865

No

3

865

864 – 866

No

4

866

865 – 867

No

5

867

866 – 878

No

  • channel widths

Band Name

Frequency Range (GHz)

Frequency Range (MHz)

Channels

North America (FCC)

0.902 – 0.928 GHz

902 – 928 MHz

26 channels (1 MHz spacing, channels 1–26)

Europe (ETSI)

0.863 – 0.868 GHz

863 – 868 MHz

5 channels (1 MHz spacing, channels 1–5)

Japan (ARIB)

0.779 – 0.787 GHz

779 – 787 MHz

4 channels (1 MHz spacing, channels 1–4)

China (SRRC)

0.920 – 0.925 GHz

920 – 925 MHz

~6 channels (varies by region)

South Korea

0.917 – 0.923 GHz

917 – 923 MHz

3 channels (varies by region)

  • Reference links