1. Bluetooth:

BlueTooth is a technology for wireless communication between devices,which can realize short-distance data exchange between fixed devices,mobile devices and building personal area networks. Bluetooth can connect multiple devices to overcome the problem of data synchronization. Bluetooth uses short-baud high-frequency (UHF) radio waves to communicate via the ISM frequency band from 2.4 to 2.485 GHz. The communication distance ranges from a few meters to a few hundred meters.

Advantage:

• In the "Bluetooth Low Energy" mode,low power consumption is realized,and the coverage range is enhanced,and the maximum range can exceed 100 meters

• Supports complex networks: optimized for one-to-one connections,and supports one-to-many connections in star topology, etc.

• Smart connection: Increase the support for setting the connection frequency between devices, and Ipv6 network support.

• High security: use AES-128 CCM encryption algorithm for data packet encryption and authentication.

• The Bluetooth module is small and easy to integrate.

• Temporary peer-to-peer connection (Ad-hoc Connection) can be established: According to the role of the Bluetooth device in the network, it can be divided into a master device (Master) and a slave device (Slave).

Disadvantages:

• The various versions of Bluetooth are not compatible, and the networking capability is poor; there are few network nodes, which is not suitable for multi-point deployment.

  
  

• Comparison of the advantages and disadvantages of three common wireless communication technologies connected to the Internet of Things

2. Wi-Fi:

Wi-Fi is a wireless local area network communication technology, the full name is Wireless-Fidelity,wireless fidelity, the IEEE 802.11 standard organized by the IEEE established the technical standard for Ethernet. Wi-Fi terminal refers to the use of high-frequency radio signals to send and receive data,the use of Ethernet communication protocol,the communication distance is usually tens of meters.

Advantage:

The advantage of Wi-Fi is that there is no need to use wires for LAN deployment,which reduces the cost of deployment and expansion. In addition,according to the Wi-Fi Alliance,"Wi-Fi certification" is backward compatible, and it specifies a set of global unified standards: Unlike mobile phones,any Wi-Fi standard equipment will operate correctly anywhere in the world.

Disadvantage:

The disadvantages of Wi-Fi are limited communication distance,poor stability,high power consumption,poor networking capability,and poor security.

Comparison of the advantages and disadvantages of three common wireless communication technologies connected to the Internet of Things

3. ZigBee:

It is a low-speed,low-power,short-range,self-organizing wireless LAN communication technology. It was formally proposed in 2003 to compensate for the high complexity of the Bluetooth communication protocol,large power consumption,short distance,and too small network scale. . The name is taken from the bee. The bee relies on the "dance" of flying and "buzzing" (zig) to flutter its wings to convey information about the location of pollen with its companions. In this way,it constitutes a communication network in the group. ZigBee is standardized as IEEE 802.15.4,and there are three working frequency bands: 868MHz-868.6MHz,902MHz-928MHz and 2.4GHz-2.4835GHz. The last frequency band is universal,with 16 channels,and this frequency band is free of charge and free of charge. The applied radio frequency band. The transmission rates of the three frequency bands are respectively 20kbps, 40kbps and 250kbps.

Advantage:

Low power consumption,large network capacity,flexible working frequency band.

Disadvantage:

The data transmission rate is low,the effective range is small,the anti-interference is poor,the ZigBee protocol is not open source,and the connection with the IP protocol is more complicated.