cmiit id stands for radio transmitting equipment type approval code.
cmitid is the type approval code for radio transmitting equipment. Radio transmitting equipment is defined as a variety of equipment that emits radio waves, but does not include industrial, scientific research, medical equipment, electrified transportation systems, high-voltage power lines and other electrical devices that can radiate electromagnetic waves.
CMIITID in the radio transmitting equipment, including cell phones (with Wi-Fi or Bluetooth), Bluetooth headsets, wireless routers, wireless cards and other wireless products are reflected in the CMIITID by the SRRC in accordance with national standards after the test is approved by the approved sales of the certificate, only with the country's radio transmitting equipment type approval code of radio transmitting equipment Only with China's radio transmitting equipment type approval code of radio transmitting equipment can be sold and used in China's domestic radio transmitting equipment.
According to the "Chinese People's *** and the State Radio Regulations" and model approval of the relevant documents, production, imported radio transmitting equipment, are required to its emission characteristics of the model approval, the issuance of "radio transmitting equipment type approval certificate" and model approval code, the factory equipment must be marked on the label model approval code. Approval code.
CMITID is designed to distinguish between civilian and military radio bands. Is in the radio transmitting equipment into use before the development, production, import, acquisition and other aspects of its spectrum parameters and technical indicators of technical management in accordance with the law.
Radio basic technical principles
From the propagation point of view, radio technology eliminates the space-time constraints. In terms of the medium of propagation, radio waves are selected for transmitting information. The transmitted signals and the corresponding reception process are all based on frequency variations. In terms of fundamental principles, radio technology is constructed according to the mechanism of electromagnetic waves.
In the range of conductors, the electromagnetic field is synchronized with the fluctuations of the electric current, and on this basis the radio waves are replaced, showing regularity. After a modulation step, the current is transformed into precise information and attached to the medium. After transmitting and receiving the information, the conductor will change the original state of the magnetic field, thus clarifying the change of current in each phase. Once fully transformed, it can be used to transmit information.
In detail, radio technology consists of waveforms of different lengths, such as long waves, short waves, and medium waves. In comparison, each length of waveform has unique transmission advantages as well as drawbacks. Over time, radio transmissions have eliminated the traditional form of transistors to create integrated circuits, which in turn have led to microwave transmissions.
Today, radio can choose to transmit digitally in new ways, with the help of mobile devices. Radio technology is being integrated into all aspects of production and daily life, demonstrating its practical value. It has been utilized in many fields. Thus, radio technology in today's era is of indispensable significance.
Reference: Baidu Encyclopedia - CMIIT ID