802.11g is a widely-deployed Wi-Fi standard that was introduced in 2003. It operates on a 2.4 GHz frequency and supports channel widths of 20 MHz. It is backward compatible with the 802.11b standard, but it has a higher data rate and more advanced modulation techniques.

802.11g can deliver data rates of up to 54 Mbps under ideal conditions. To achieve this speed, both the access point (AP) and the client device must support 802.11g and operate in the same frequency band with the same channel width. The distance and the number of obstacles between the two devices also affect the data rate. It is important to note that the actual throughput may be lower than the data rate due to overhead and other factors.

Compared to its predecessor, 802.11b, 802.11g offers almost five times faster data rates. This makes it suitable for applications that require higher bandwidth, such as video streaming, file sharing, and online gaming. However, it may not be sufficient for very demanding applications, such as 4K video streaming, virtual reality, or cloud gaming, which require even higher data rates.

802.11g uses the same modulation schemes as 802.11b, which are Differential Binary Phase Shift Keying (DBPSK) and Differential Quadrature Phase Shift Keying (DQPSK) for lower data rates, and Complementary Code Keying (CCK) for higher data rates. However, it also introduces a new modulation scheme called Orthogonal Frequency Division Multiplexing (OFDM), which is more efficient in handling interference and multipath fading.

In terms of security, 802.11g supports the same encryption algorithms as 802.11b, such as Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), and Wi-Fi Protected Access II (WPA2). However, it also introduces a new encryption algorithm called Temporal Key Integrity Protocol (TKIP), which enhances the security of WPA.

Despite its advantages, 802.11g has some limitations. One of them is the interference from other devices that operate on the same frequency band, such as cordless phones, microwave ovens, and Bluetooth devices. This can degrade the performance of the Wi-Fi network and reduce the data rate. Another limitation is the range, which may be shorter than the 802.11b range due to the higher frequency and the use of OFDM.

In conclusion, 802.11g is a relatively fast Wi-Fi standard that offers higher data rates than 802.11b and is suitable for most applications that require moderate to high bandwidth. However, it may not be sufficient for very demanding applications, and it has some limitations in terms of interference and range. Nowadays, newer Wi-Fi standards such as 802.11ac and 802.11ax offer even higher data rates, better performance, and more advanced features, and are gradually replacing 802.11g in the market.