Near field communication

Currently commonly used wireless network standards: ZigBee, Bluetooth, WiFi. Short-range wireless communication 2.4GHZ band.

Zigbee is synonymous with IEEE 802. 15.4 protocol. The name comes from the eight-character dance of bees. Because bees communicate with their companions by flying and flapping their wings, that is to say, bees rely on this way to form a communication network in groups.

Its characteristics are short distance, low complexity, self-organization, low power consumption, low data rate and low cost. It is mainly applicable to the fields of automatic control and remote control, and can be embedded in various devices.

ZigBee can adaptively find longer but available routing lines. This unique architecture makes ZigBee have the characteristics of short distance, low complexity, self-organization, low power consumption and high data rate.

Because of these characteristics, ZigBee is mainly used in the fields of automatic control and remote control to meet the wireless networking and control of small and cheap equipment. The typical application is wireless sensor network. In the fields of home/business automation, intelligent energy, health care and retail, ZigBee has also proved to be a reliable wireless network solution.

The technical advantages of ZigBee mainly include the following aspects:

At the same time, ZigBee also has some disadvantages:

Bluetooth technology is committed to enabling all mobile or non-mobile devices supporting this technology to easily establish network connection and conduct voice and data communication in the space of 10m.

The Bluetooth Special Interest Group (SIG) recently announced the formal adoption of bluetooth profile version 4.0, and launched the corresponding certification plan. Version 4.0 adds high-speed transmission technology on the basis of 3.0+HS standard, and also adds Wibree low-power transmission technology pushed by Nokia before.

At this point, Bluetooth is no longer the familiar "Bluetooth" that only applies to WPAN. It is a "three-in-one" Bluetooth which integrates IEEE 802. 15. 1 traditional Bluetooth, IEEE 802.1physical layer, MAC layer and Wibree standard.

As the focus of Bluetooth version 4.0, the low-power transmission part follows the previous Wibree standard. With simple GFSK modulation, it has extremely low running and standby power consumption, and can even work continuously with a button cell for several years.

Undoubtedly, the new low-power Bluetooth will challenge technologies such as ZigBee and NFC. Compared with the star topology of ZigBee, the network topology of low-power Bluetooth is much simpler, and the transmission distance has great advantages over NFC. Although a latecomer, with its leading position in the field of mobile phones and audio, its future development is worth looking forward to.

Bluetooth headset Bluetooth mouse and keyboard

WiFi (wireless fidelity), namely IEEE 802. 1 1 protocol, is a short-distance wireless transmission technology, which can support radio signals connected to the Internet within hundreds of feet. The basic network structure and transmission medium of WLAN are specified, and the characteristics of physical layer (PHY) and media access layer (MAC) are standardized. The physical layer adopts infrared, DSSS (direct sequence spread spectrum) or FSSS (frequency modulation spread spectrum) technology. 1999 adds IEEE 802.1a and IEEE 802. 1 1G standards. Its transmission rate can reach up to 54 MB/s, and it can widely support data, image, voice and multimedia services.

The radio coverage of Bluetooth is very small, the radius is only about 15 m, while the radius of WiFi can reach 100 m, even covering the whole building.