The so-called "Internet of Things" refers to a huge network formed by combining various information sensing devices, such as radio frequency identification (RFID) devices, infrared sensors, global positioning systems, laser scanners and other devices with the Internet. Its purpose is to connect all items with the network for easy identification and management. The Internet of Things is established by ubiquitous network technology, among which the most important technology is RFID electronic tag technology.
Based on simple RFID system, combined with existing network technology, database technology, middleware technology, etc. It has become the development trend of RFID technology to build the Internet of Things composed of a large number of networked readers and numerous mobile tags. In this network, the system can identify, locate, track, monitor and trigger corresponding events automatically and in real time.
The Internet of Things is also called "sensor network". The computer network technology represented by the Internet is a great achievement of computer science in the 20th century, which has brought profound changes to our lives. However, at present, no matter how powerful the network function is and how rich the network world is, it is still virtual and separated from the real world in which we live. In the network world, it is difficult to perceive the real world, and many things are still impossible. The times call for new network technology.
Wireless sensor network is a brand-new network technology under this background. It integrates sensor, low power consumption, communication and MEMS technology. It can be predicted that in the near future, wireless sensor networks will bring revolutionary changes to our lifestyle.
Definition: A wireless network composed of randomly distributed tiny nodes through self-organizing integration of sensors, data processing units and communication units.
Chinese name: wireless sensor network; ; Abbreviation: WSN
Function: With the help of the sensor built in the node, we can measure the signals of heat, infrared, sonar, radar and seismic waves in the surrounding environment, so as to detect material phenomena including temperature, humidity, noise, light intensity, pressure, soil composition, size, speed and direction of moving objects.
At present, the relatively formed framework of distributed network integration is EPC network proposed by EPCglobal. EPC network is mainly aimed at the logistics field, and its purpose is to increase the visibility and control of supply chain, so that the whole logistics field can obtain greater economic benefits with the help of RFID technology.
Future world: the Internet of Things woven by sensors. Lifestyle will move from "feeling" to "perceiving" the Internet era, and the network is the information dissemination between people. In the future, the network will be the information exchange between things. The Internet of Things, also known as sensor networks, can be applied from military counter-terrorism to urban construction, transportation to families and individuals. "If you arrange sensors at home, you can know the situation in every corner of your home in the wild. If you put sensors on your body, the hospital can know your health at any time. " Mr. Liu Haitao, President of the Institute, revealed that when the Internet of Things is connected with the Internet and mobile communication networks, people can "perceive" each other in all directions at any time and place, and people's lifestyle will change from "feeling" to "perception".
The key technologies of EPC network include:
EPC code: ID code with length of 64 bits, 96 bits and 256 bits. For the sake of cost, 64-bit and 96-bit coding are mainly used now. EPC code is divided into four fields, namely: ① header, which identifies the version number of the code, so that the electronic product code can adopt different lengths and types; (2) product managers, such as product manufacturers; (3) Product category; ④ The unique number of the project.
Savant is the middleware between reader and enterprise application, which provides a series of computing functions for enterprise application. Its main task is to reduce the amount of data transmitted from readers to enterprise applications, filter, collect and calculate tag data read by readers, and Savant also provides interoperability with ons, PML servers and other savants.
Object name service, similar to domain name server DNS, ONS provides the service of parsing EPC code into a URL or a group of URLs, through which further information about EPC-related products can be obtained.
Information service stores product-related information in PML format, which can be retrieved by other applications and returned in PML format. The stored information can be divided into two categories: one is the historical event record related to time, such as the original RFID reading event (when the tag was recorded and read by which reader), and the high-level activity record such as the transaction event (recording the tag involved in the transaction); The other is the inherent attribute information of the product, such as production time, shelf life, volume, color and so on.
Physical Markup Language (PML) is an extension of XML and is considered as a unified standard to describe all natural objects, processes and environments. In EPC network, all information about goods is described by Physical Markup Language (PML), which is the standard format for information storage and exchange in EPC network.