In order to allow the monitoring center to communicate with multiple GPRS modules at the same time, multiple work sites can be monitored.
The Bluetooth system consists of a wireless unit, a link controller, a link manager, and a support unit that provides functions to the host interface.
The Bluetooth wireless unit is a microwave frequency hopping spread spectrum communication system in which data and voice information packets are transmitted and received at designated time slots with specified frequency hopping frequencies. The hopping sequence is determined by the address of the master device, and the channel connection is established by paging and inquiry. The link control (baseband control) includes the hardware portion of the baseband digital signal processing and performs the baseband protocol and other underlying link procedures. Link Manager (LM) software implements link establishment, verification, link configuration, and protocol. The link manager can discover other link managers and establish communication links through the connection management protocol LMP. The link manager implements the above functions through the services provided by the link controller.
The design of the Wi-Fi solution is relatively simple compared to other solutions. It only needs to control the WIFI module through the MCU, communicate with the motherboard through the CAN bus, and then transmit the message to the Internet through the WIFI module. By connecting to the server, the server processes the data.
Infrared communication mainly consists of three parts:
(1) Transmitter part: At present, information sources of infrared wireless digital communication systems include voice, data, images and the like.
(2) Channel parts: Their functions are: shaping, filtering, field of view conversion, frequency band division, and so on.
(3) Terminal part: The terminal part of the infrared wireless digital communication system includes a light receiving part, sampling, filtering, decision, quantization, equalization and decoding.
UWB (UltraWideband) is a carrierless communication technology that uses a non-sinusoidal narrow pulse of nanoseconds to picoseconds to transmit data. UWB can achieve data transmission rates of hundreds of Mbit/s to several Gbit/s in a range of about 10 meters by transmitting extremely low power signals over a wide spectrum.
Technology is a two-way wireless communication technology with close proximity, low complexity, low power consumption, low speed and low cost. It is mainly used for data transmission between various electronic devices with short distance, low power consumption and low transmission rate, and typical applications with periodic data, intermittent data and low response time data transmission.
Like RFID, NFC information is also transmitted by electromagnetic induction coupling of the radio frequency portion of the spectrum, but there is still a big difference between the two. First, NFC is a wireless connection technology that provides easy, secure, and fast communication with a smaller transmission range than RFID. Second, NFC is compatible with existing contactless smart card technologies and has become the official standard supported by more and more major vendors. Once again, NFC is a close-range connection protocol that provides easy, secure, fast, and automatic communication between devices. Compared to other connections in the wireless world, NFC is a close-range, private communication method.