802.11k Channels

What is the purpose of channel management in 802.11k?

802.11k provides mechanisms to scan, measure, and report on wireless channels to optimize channel usage and reduce interference.

Which frequency bands does 802.11k support for channels?

It supports both 2.4 GHz and 5 GHz bands, inheriting the channel plans of underlying 802.11 standards.

How does 802.11k help with channel selection?

By enabling access points and clients to perform radio measurements and report channel conditions for better channel assignment.

Does 802.11k define new channels?

No, it uses existing channels defined by legacy 802.11 standards but adds tools for assessing channel quality.

What is a channel scan in 802.11k?

A process where devices scan all available channels to measure parameters like signal strength and noise levels.

What types of measurements are done on channels in 802.11k?

Measurements include Received Channel Power Indicator (RCPI), Channel Load, Noise Histogram, and Beacon Reports.

How often are channel measurements performed?

Measurement frequency depends on network configuration and environmental dynamics.

Who initiates channel measurements in 802.11k?

Usually the access point or the client device can trigger measurements through request frames.

What is a Beacon Report in the context of 802.11k channels?

It is a measurement report that contains information about neighboring APs and channel conditions.

How does 802.11k improve roaming decisions with channel info?

By providing detailed channel measurements, clients can choose the best AP based on channel quality.

Are channel widths considered in 802.11k measurements?

Yes, measurements can be tied to specific channel widths like 20 MHz or 40 MHz depending on the PHY.

Can 802.11k help detect channel interference?

Yes, channel load and noise measurements help identify congested or interfered channels.

What is the role of Neighbor Reports in channel management?

Neighbor Reports provide info about neighboring APs including their channels, aiding channel planning.

Does 802.11k support dynamic channel switching?

While 802.11k provides the measurement data, dynamic channel switching is handled by other mechanisms or standards.

What is Channel Load measurement?

It measures the percentage of time the channel is busy, helping assess congestion levels.

How does Noise Histogram measurement help in 802.11k?

It provides a distribution of noise levels on a channel to help in interference analysis.

Can 802.11k measurements be used for regulatory compliance?

Indirectly, by ensuring devices operate on allowed channels and avoid congested bands.

How are channel measurements reported in 802.11k?

Reports are sent in measurement report frames encapsulated within MAC frames.

Is 802.11k backward compatible in channel operations?

Yes, it is designed to interoperate with legacy 802.11 devices without affecting channel plans.

What benefits do channel measurements provide to network administrators?

They enable better planning, interference mitigation, and improved overall WLAN performance.

Topics in this section,

Channel Number (MHz)

Center Frequency (MHz)

Frequency Range

DFS Required

1

2412

2401 – 2423

No

2

2417

2406 – 2428

No

3

2422

2411 – 2433

No

4

2427

2416 – 2438

No

5

2432

2421 – 2443

No

6

2437

2426 – 2448

No

7

2442

2431 – 2453

No

8

2447

2436 – 2458

No

9

2452

2441 – 2463

No

10

2457

2446 – 2468

No

11

2462

2451 – 2473

No

12

2467

2456 – 2478

No (region dependent)

13

2472

2461 – 2483

No (region dependent)

14

2484

2473 – 2495

No (Japan only)

Channel Number (MHz)

Center Frequency (MHz)

Frequency Range

DFS Required

36

5180

5170 – 5190

No

40

5200

5190 – 5210

No

44

5220

5210 – 5230

No

48

5240

5230 – 5250

No

52

5260

5250 – 5270

Yes

56

5280

5270 – 5290

Yes

60

5300

5290 – 5310

Yes

64

5320

5310 – 5330

Yes

100

5500

5490 – 5510

Yes

104

5520

5510 – 5530

Yes

108

5540

5530 – 5550

Yes

112

5560

5550 – 5570

Yes

116

5580

5570 – 5590

Yes

120

5600

5590 – 5610

Yes

124

5620

5610 – 5630

Yes

128

5640

5630 – 5650

Yes

132

5660

5650 – 5670

Yes

136

5680

5670 – 5690

Yes

140

5700

5690 – 5710

Yes

144

5720

5710 – 5730

Yes

149

5745

5735 – 5755

No

153

5765

5755 – 5775

No

157

5785

5775 – 5795

No

161

5805

5795 – 5815

No

165

5825

5815 – 5835

No

  • channel widths

Band Name

Frequency Range (GHz)

Frequency Range (MHz)

Channels

2.4 GHz Band

2.400 – 2.485

2400 – 2485

1 – 14 (region dependent)

UNII-1

5.150 – 5.250

5150 – 5250

36, 40, 44, 48

UNII-2 (DFS)

5.250 – 5.350

5250 – 5350

52, 56, 60, 64

UNII-2 Extended (DFS)

5.470 – 5.725

5470 – 5725

100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144

UNII-3

5.725 – 5.825

5725 – 5825

149, 153, 157, 161, 165

  • Reference links