The 2.4 GHz ISM band is a widely used unlicensed radio frequency band for devices such as wireless routers, as well as wireless PC peripherals such as a mouse or keyboard. These devices may use standard protocols such as the IEEE 802.11b/g/n or Bluetooth, or they may use proprietary protocols. The radios may use frequency hopping, frequency agility, or may operate on a fixed frequency. In order for a wireless radio receiver to detect the received signal correctly, the received signal power must be greater than the sensitivity of the radio. The sensitivity limit of the receiver is influenced by the minimum Signal-to-Noise Ratio (SNR) required for demodulation.