In IEEE 802.11 wireless networking, what is the operating frequency band used by the 802.11g standard?

Introduction / Context:
The IEEE 802.11 family of standards defines wireless LAN technologies that operate in different frequency bands and support various data rates. Knowing which standard uses which band is fundamental for wireless design, interference analysis and exam preparation. The 802.11g standard is a widely deployed legacy standard that extended earlier 2.4 GHz technologies while increasing throughput.

Given Data / Assumptions:

We are dealing with the IEEE 802.11g wireless LAN standard.

The question asks specifically about its frequency band, not its data rate.

802.11g was designed as an evolution of 802.11b.

Other 802.11 variants such as 802.11a and 802.11ac use different frequency bands.

Concept / Approach:
IEEE 802.11g operates in the 2.4 GHz ISM band, the same frequency range used by 802.11b. It was designed to provide higher data rates while maintaining backward compatibility with 802.11b devices. In contrast, 802.11a operates in the 5 GHz band, and more modern standards such as 802.11n and 802.11ac can operate in both bands or extend into higher frequency ranges. Therefore, the correct answer must indicate the 2.4 GHz band.

Step-by-Step Solution:
Recall that 802.11g was introduced as a higher speed extension of 802.11b, which already used the 2.4 GHz band, so 802.11g also uses 2.4 GHz. Remember that 802.11a was the standard that primarily used the 5 GHz band instead, so 5 GHz is not correct for 802.11g. Data rates are measured in Mbps, not Gbps, for 802.11g, so any option that lists Gbps is confusing frequency with throughput and should be considered incorrect in this context. The option that correctly names the operating band is 2.4 GHz. Therefore, option c is the correct answer.

Verification / Alternative check:
Vendor datasheets and Wi-Fi certification documents typically list 802.11b and 802.11g as operating in the 2.4 GHz band, usually in the 2.4 to 2.4835 GHz range, depending on regulatory domains. Conversely, they list 802.11a and some later 802.11ac and 802.11ax modes as operating in the 5 GHz band. This reinforces that 802.11g is firmly associated with 2.4 GHz.

Why Other Options Are Wrong:
Option a, 2.4 Gbps, confuses a frequency label with a data rate in gigabits per second and does not accurately describe a wireless band.

Common Pitfalls:
Option b, 5 Gbps, again uses the wrong unit and band, and more closely relates to later multistream technologies, not 802.11g.
Option d, 5 GHz, is correct for 802.11a and parts of 802.11n and 802.11ac, but not for 802.11g.
Option e, 900 MHz, is used in some specialised wireless systems but is not part of mainstream IEEE 802.11 WLAN standards like 802.11g.

Common Pitfalls:
A common source of confusion is mixing up which standards use 2.4 GHz and which use 5 GHz, especially now that dual band access points are common. A simple memory aid is that 802.11b and 802.11g are 2.4 GHz, while the original 802.11a is 5 GHz. Later standards like 802.11n can use both bands, and 802.11ac and newer primarily use 5 GHz and beyond.

Final Answer:
The IEEE 802.11g standard operates in the 2.4 GHz frequency band.