Wi-Fi type of modulation ( e.g., WiMAX ). Breezecom/Alvarion/Symbol/Raylink spread spectrum frequency hopping networks . Western Multiplex or Proxim non- Wi-Fi wireless links ( e.g., Lynx ). HomeRF spread spectrum frequency hopping network . ZigBee IEEE 802.15.4 sensor wireless network . Microwave fruit drying oven, plastic mold preheater. Unstable high power