In Wi-Fi, "PHY" stands for Physical Layer. It's the lowest layer of the OSI model (Open Systems Interconnection model) that defines how data is physically transmitted over the airwaves. The PHY layer dictates the physical characteristics of the wireless signal, such as:
- Frequency: The specific radio frequency band used for transmission (e.g., 2.4 GHz or 5 GHz).
- Modulation: The method used to encode data onto the radio waves.
- Encoding: The way data bits are organized and structured for transmission.
- Antenna: The type of antenna used for signal transmission and reception.
PHY Rate refers to the actual speed at which data is transmitted over the Wi-Fi network. This rate is determined by factors like the selected Wi-Fi standard (e.g., 802.11n, 802.11ac), the number of antennas used, and the channel width.
For example, a Wi-Fi network using 802.11ac with two antennas could have a PHY rate of 800 Mbps, while a network using 802.11n with one antenna might have a PHY rate of 65 Mbps.
The PHY layer is crucial for ensuring reliable and efficient wireless communication. Different PHY standards have different capabilities and limitations, impacting factors like speed, range, and interference resistance.
