802.11g Channels

What are channels in 802.11g?

Channels in 802.11g refer to specific frequency ranges in the 2.4 GHz band on which wireless devices communicate.

How many channels are available in 802.11g?

802.11g supports up to 14 channels globally, though availability depends on regional regulations.

What is a frequency band in wireless communication?

A frequency band is a specific range of frequencies within the radio spectrum used for communication.

Which frequency band does 802.11g operate in?

802.11g operates in the 2.4 GHz frequency band, specifically between 2.4 GHz and 2.4835 GHz.

What are ISM bands in 802.11g?

ISM (Industrial, Scientific, Medical) bands are unlicensed frequency ranges, including the 2.4 GHz band used by 802.11g.

What is channel width in 802.11g?

Channel width refers to the size of the frequency band used to transmit data. In 802.11g, it is 20 MHz.

Why does 802.11g use 20 MHz channels?

20 MHz channels balance throughput and interference, standardizing device operation in the crowded 2.4 GHz band.

Are 802.11g channels overlapping?

Yes, adjacent 20 MHz channels in 2.4 GHz overlap, causing interference if not carefully planned.

What determines the number of usable channels?

Regional regulations and interference considerations limit usable channels, commonly to 3 non-overlapping channels (1, 6, 11).

What is Dynamic Frequency Selection (DFS)?

DFS is generally not required in 2.4 GHz for 802.11g due to the band’s regulatory status.

What is Transmit Power Control (TPC)?

TPC adjusts transmit power to optimize link quality and minimize interference in 802.11g networks.

Can 802.11g use 40 MHz or 80 MHz channels?

No, 802.11g only supports 20 MHz channels; wider channels were introduced in 802.11n and later.

Why is channel planning important in 802.11g?

It reduces interference from overlapping channels and other 2.4 GHz devices, improving network reliability.

Are all 2.4 GHz channels available globally?

No, channel availability varies slightly by country due to different regulations.

Can devices auto-select 802.11g channels?

Yes, many devices scan and choose the least congested channel automatically.

How do clients know which channel to use?

Clients scan for access points broadcasting beacons and connect on their advertised channels.

What is the channel center frequency?

The midpoint frequency of a channel. For example, Channel 1 centers at 2.412 GHz.

How are 802.11g channels numbered?

Channels are numbered 1 through 14 depending on regional allowance, spaced by 5 MHz increments.

What are the typical channel numbers for 802.11g?

Commonly used channels are 1, 6, and 11 to avoid overlap.

How far apart are 802.11g channels spaced?

Channels are spaced 5 MHz apart but use 20 MHz width causing overlap.

What is co-channel interference?

When multiple APs use the same channel, causing contention and degraded throughput.

How can co-channel interference be avoided in 802.11g?

By carefully selecting channels 1, 6, and 11 and spacing access points appropriately.

Does weather affect 2.4 GHz channel performance?

Generally minimal indoors; 2.4 GHz penetrates walls better than 5 GHz.

Why is 2.4 GHz considered more congested than 5 GHz?

Many devices (Bluetooth, microwaves, cordless phones) use 2.4 GHz, causing interference.

What is the typical range of 802.11g channels?

2.4 GHz offers longer range than 5 GHz, typically up to 70 meters indoors.

Can 802.11g channels be used outdoors?

Yes, subject to local regulations and power limits.

What happens if two APs use the same channel?

They share the medium and compete, which can lower throughput.

What tools help with 802.11g channel planning?

Wi-Fi analyzers, spectrum scanners, and site survey tools assist planning.

Topics in this section,

Channel Number (MHz)

Center Frequency (MHz)

Frequency Range (MHz)

1

2412

2401 – 2423

2

2417

2406 – 2428

3

2422

2411 – 2433

4

2427

2416 – 2438

5

2432

2421 – 2443

6

2437

2426 – 2448

7

2442

2431 – 2453

8

2447

2436 – 2458

9

2452

2441 – 2463

10

2457

2446 – 2468

11

2462

2451 – 2473

12

2467

2456 – 2478

13

2472

2461 – 2483

14

2484

2473 – 2495 (Japan only)

  • channel widths

Band Name

Frequency Range (GHz)

Frequency Range (MHz)

Channels

2.4 GHz ISM Band

2.400 – 2.4835

2400 – 2483.5

1 – 14 (region-dependent)

  • Reference links