1) Near field communication
Communication method: RFID, NFC, Bluetooth, IrDA.
Communication characteristics:
RFID-Low frequency: The communication distance is within 1m, the communication speed is low, and the card is large.
RFID-high frequency: The communication distance is within 1m, the communication speed is medium, and the card is small.
RFID-Ultra high frequency: The general communication distance is 4~6m, and some active products can reach 30m.
NFC: With a communication distance of 20cm, it is easier to use and safer than RFID.
Bluetooth: The common communication distance is 10m, and the high-power products can reach 100m.
IrDA: High communication speed and strong anti-interference ability.
2) Long distance communication
Communication method: WIFI, 433M, 2.4G, ZIGBEE,3G.
Communication characteristics:
WIFI: Working frequency: 2.4ghz, communication distance: 50m.
433M: Working frequency: 433mhz, communication distance: 50m.
2.4G: Working frequency: 2.4ghz, communication distance: 50m.
ZIGBEE: Working frequency: 2.4ghz, communication distance: 50m.
3G: Working frequency coverage: 1.8ghz~ 2.4ghz; communication distance: extending through the base station, the signal is everywhere.