1. **Wi-Fi 1 (802.11b)**:
- Frequency: 2.4 GHz
- Speed: Up to 11 Mbps
- Introduced: 1999
- Characteristics: Better range but susceptible to interference from other devices using the same frequency.
2. **Wi-Fi 2 (802.11a)**:
- Frequency: 5 GHz
- Speed: Up to 54 Mbps
- Introduced: 1999
- Characteristics: Higher speeds but shorter range and less interference.
3. **Wi-Fi 3 (802.11g)**:
- Frequency: 2.4 GHz
- Speed: Up to 54 Mbps
- Introduced: 2003
- Characteristics: Combines the speed of 802.11a with the range of 802.11b.
4. **Wi-Fi 4 (802.11n)**:
- Frequency: 2.4 GHz and 5 GHz
- Speed: Up to 600 Mbps
- Introduced: 2009
- Characteristics: Improved speed, range, and reliability with support for MIMO (Multiple Input Multiple Output).
5. **Wi-Fi 5 (802.11ac)**:
- Frequency: 5 GHz
- Speed: Up to 3.5 Gbps
- Introduced: 2014
- Characteristics: Higher speeds and better performance, particularly in crowded environments, with wider channel bandwidths and more spatial streams.
6. **Wi-Fi 6 (802.11ax)**:
- Frequency: 2.4 GHz and 5 GHz
- Speed: Up to 9.6 Gbps
- Introduced: 2019
- Characteristics: Enhanced performance in dense environments, improved efficiency with OFDMA (Orthogonal Frequency Division Multiple Access), and better power management.
7. **Wi-Fi 6E**:
- Frequency: 2.4 GHz, 5 GHz, and 6 GHz
- Speed: Up to 9.6 Gbps
- Introduced: 2020
- Characteristics: Extension of Wi-Fi 6 into the 6 GHz band, offering more spectrum and reduced interference, leading to higher performance and lower latency.
8. **Wi-Fi 7 (802.11be)**:
- Frequency: 2.4 GHz, 5 GHz, and 6 GHz
- Speed: Up to 30 Gbps
- Expected: 2024+
- Characteristics: Significantly higher speeds, lower latency, better efficiency with wider channels, enhanced MIMO, and improved multi-link operation.
These standards reflect the ongoing advancements in Wi-Fi technology, addressing the increasing demands for faster, more reliable, and efficient wireless connectivity.