One of the Internet of things era

EPC (Electric Product Code) is a standard for the sensing layer of the Internet of things, mainly to define how to define the electronic tag, which includes many rules.

The Internet of things is divided into three layers: the perceptual layer, the network layer and the application layer. Perceptual layer is the direct contact layer of objects and objects, like the battlefield of war, such as our bus, IC card and receiver is in the perceptual layer, is the matter and things between each other perception, interaction layer, the layer of technology has RFID (radio frequency Technology), the role of perceptual layer is to interactively collect information, response information Network layer is the transmission of information collected and response information, in fact, is a "channel" or "Road" role, Information highway! The technology room of the network layer builds the expressway, then uses the highway, and finally recalls the expressway; what's it like? Engineering Corps, responsible for paving and bridging. Here the technology includes Bluetooth technology (bluetooth headset), ZigBee technology (such as remote control) and WiFi technology, no line by technology, need to have hot spots, a receiving point, is a master-slave relationship, the application layer is the data transmitted over the application of the processing, such as logging to the database, such as the processing of business logic, such as whether the user balance is sufficient, such as IBM's introduction of Smart city, this wisdom analysis is carried out in the application layer.

The first is the RFID technology in this place, there are several components: Reader, electronic label (receiver), there are three kinds of active mode, passive mode and semi-active mode in working mode. The active mode is that the receiver has its own power, can actively send messages to the reader, the passive mode electronic tag is not a power source, completely dependent on the coupling coil into the reader's radiation near field (sphere of influence), the energy provided to let the electronic label work, to send readers their own information Semi-active is the internal power supply, but the power supply is only to maintain its internal information storage, the power to send the message or from the reader's voltage difference, when the source is to compensate for the reader's RF power is not enough, to strengthen the power to the reader push data, This mode is out of state when it is not in the reader area, it is activated only after entering the area, it is very power-saving, and the battery can last up to 10 years. This is like in the dance, the electronic tag is waiting for the woman, the reader is a man, the active mode is the female heart has the power, can take the initiative to interact with the male guests: Hi, handsome, my name is light rain. Passive mode will never be active to communicate with the handsome, waiting for the call of handsome man: beautiful, can you meet? At this time the woman will say: Oh, my name is Daiyu. Half have the source is the girl more heart, when found the right boy some timid, will use eyes, tone and other ways to encourage each other to understand themselves.

Operating frequency to divide, 1. Low band electronic label, this kind of label sensing range is small, mostly passive label, the application range is less than 1m, the disadvantage is that the information is small, and only suitable for low-speed scene 2. Medium-High Frequency electronic label, also mostly passive electronic label, must be in the range of the reader antenna radiation; ultra-high-frequency wireless microwave technology, can be active or passive, for the active, the reader's antenna radiation will wake up its power supply work, and with the reader to send information

RFID: Radio frequency identification, composed of four parts, a signal transmitter (RF card, transponder, divided into active, passive, semi-active), signal receiver (reader, used to form a magnetic field), the programmer (for reading and writing labels to erase), antenna (enhanced signal)

There are two kinds of RF technology, an inductive coupling method, the signal transmitter is mostly passive, relying entirely on the magnetic field provided by the reader to work, one is the reverse scattering coupled RFID system, the reverse scattering is simulated bat, electromagnetic waves encountered a barrier, will be partially returned to the transmitting antenna (and is amplified by the transmitting antenna, Some of the electromagnetic waves will be absorbed, and will be lost in other directions, this is similar to sweeping street and telecommunications fraud, a large number of attempts have been "missing", but there is always a lot of return), backscatter in the UHF (VHF, ultra high Frequency) and SHF (UHF, Superhigh frequency) Frequency range, international standards are strict power limits, so after the free space attenuation, the transponder (electronic label) after receiving may not provide sufficient energy, this time requires the transponder self-powered to provide emission energy. A common technique for backscatter is the surface acoustic wave transponder, which relies on sound waves instead of electromagnetic waves to read and write accordingly.

The three main functions of RFID middleware: adaptation transponder, filtering (event manager) and application interface. The structure is as follows:

One of the Internet of things era