The overall structure of the Internet of Things can be divided into two parts: radio frequency identification system and information network system. Radio frequency identification system is mainly composed of tags and readers, which communicate through RFID air interface. After the reader obtains the product identification, it uploads the product identification to the middleware of the information network system through the Internet or other communication methods, and then obtains the object name of the product through ONS analysis, and then obtains various related services of product information through various interfaces of EPC information service. The operation of the whole information system will depend on the internet network system, using communication protocols and description languages developed based on the internet. Therefore, we can say that the Internet of Things is the sum of information services about various physical products based on the Internet. From the application point of view, three aspects in the Internet of Things are worthy of attention, that is, the Internet of Things consists of three parts: one is the sensor network based on two-dimensional code, RFID and sensor to realize the identification of "things". The second is transmission network, that is, data transmission and calculation are realized through the existing Internet, radio and television networks and communication networks. The third is the application network, that is, the input and output control terminal.
EPC system is a very advanced, comprehensive and complex system. Its ultimate goal is to establish a global open identification standard for each item. As shown in Figure 2.4, it is mainly composed of EPC system, RFID system and information network system [17].
Figure 2.4 EPC system composition diagram
(1)EPC coding standard
EPC coding is an important part of EPC system. It encodes entities and related information of entities, and establishes a universal information exchange language through unified and standardized coding.
(2)EPC label
EPC tag is a kind of radio frequency tag loaded with product electronic code. Generally, an EPC tag is installed on an identified object and stores information about the identified object. The information in the tag memory can be read/written by the reader in a non-contact manner.
3.2 EPC system characteristics
(1) open architecture
The EPC system adopts the largest public Internet system in the world. This avoids the complexity of the system, greatly reduces the cost of the system, and is also conducive to the value-added of the system. Metcalfe's law shows that the great value of the network lies in that the user-oriented system should be an open structural system, which is far more valuable than the complex multiple structures.
(2) Independent platform and high interactivity
The object identified by EPC system is a very extensive entity object, so it is impossible to have a technology that can be applied to all the identified objects. At the same time, the technical standards of RFID in different regions and countries are different. Therefore, an open architecture must have an independent platform and a high degree of interoperability. The EPC system network is built on the Internet network system and can work with all possible components of the Internet network.
(3) a flexible and sustainable development system
EPC system is a flexible, open and sustainable system, which can be upgraded without replacing the original system. The operation of the whole EPC network depends on the intervention of RFID system and network application system, which makes the product information spread effectively. Readers installed in different demand chain environments can read product data stored in tags. Therefore, supply chain data can be checked, updated or exchanged in time through the network.
3.3 EPC coding standard
EPC code is a new generation coding standard compatible with EAN/UPC code. In EPC system, EPC coding is combined with the current GTIN, so EPC has not replaced the current bar code standard, but gradually transitioned from the current bar code standard to EPC standard, or EPC and EAN. UCC system will exist in the future supply chain. The allocation of code segments in EPC is managed by EAN. China UCC, EAN GTIN code. UCC system is uniformly distributed and managed by China Article Coding Center. Similarly, ANCC will soon launch EPC services to meet the needs of domestic enterprises to use EPC.
EPC code is a set of numbers, which consists of a version number plus three other pieces of data (domain name manager, object classification and serial number in turn). Wherein the version number identifies the version number of EPC, so that the subsequent code segments of EPC have different lengths; Domain name management is the information describing the manufacturers related to the EPC.
Chapter IV Application of Internet of Things in Family
With the development of the times, China has gradually entered an aging society. In the future, our society will face a young couple who will take care of 2 ~ 6 pairs of old people while taking care of their children, which is a difficult problem for the whole society. It is obviously unrealistic for every family to hire a nanny; Then, this problem can only be solved by scientific and technological means. By improving the quality of family life, facilitating the information exchange between the family and the outside world, and sensing what happens at home with sensor nodes, it has laid a social foundation for the realization of the family Internet of Things.
The concept of Internet of Things is very popular, which also makes people see the future development trend of society. However, most of the Internet of Things is still in the conceptual stage, and its real scale application will take some time. The family area is relatively small and the demand is clear, so it is most likely to give priority to the application of the Internet of Things. This is not only the practical needs of modern families (taking care of the elderly and children), but also the increasing family safety of people.
4. 1 application field of home internet of things
In the cold winter, the heating system makes families in northern cities warm, but when most people leave home for work during the day, the empty rooms are still warm as spring. We need an intelligent heating control system. In the fields of production safety, food hygiene, engineering control, urban management, people's daily life and even people's entertainment activities, it is necessary to establish an intelligent system that can communicate with objects at any time. Through electronic tags (RFID), sensors, two-dimensional codes, etc. installed on various objects. They are connected to the wireless network through interfaces, thus endowing objects with intelligence and realizing the communication and dialogue between people and things, things and things. By installing sensors on the watt-hour meter, the power supply department can know the power consumption of users at any time, realize efficient integrated management such as power consumption inspection, power quality monitoring, load management, line loss management and demand side management, and reduce the power consumption loss for one year. When the elevator is equipped with sensors, passengers don't need to call the police. The elevator management department will get the information at the first time with the help of the network and go to the scene to deal with the fault as quickly as possible.
4.2 Development process
1999 put forward the concept of internet of things. During the period of 10, countries all over the world are stepping up their research. The development of the Internet of Things can be divided into four stages: the first stage is the networking between mainframes and hosts, the second stage is the connection between desktops and notebooks and the Internet, the third stage is the interconnection of some mobile devices such as mobile phones, and the fourth stage is the rise of embedded Internet. More application equipment closely related to people's daily life, including washing machines, refrigerators, televisions, microwave ovens, etc., will join the ranks of interconnection and eventually form a global unified "Internet of Things".
For the Internet, the 1980s was the golden age, during which a famous figure-Bob? BobKahn, he is called the father of the Internet (and several others have been given the same name). While making outstanding contributions to the Internet, he also laid the foundation stone for another project, namely the Distributed Sensor Network (DSN) which began in 1980s. The sensor in those days was much bigger than this one in my hand and had to be pulled by truck. Such large sensors are organized into nodes and connected with each other by microwaves, thus forming a sensor network.
The huge sensor can't keep up with people's expectations of its function in size, so researchers began to think about whether it can be made smaller and smaller. Then, in the 1990s, an interesting concept "SmartDust" appeared, which was put forward by KrisPister, a professor at the University of California, Berkeley. This concept holds that the calculation and communication can be integrated into an ultra-micro sensor with an area of about 1~2 square millimeters to detect the parameters of the surrounding environment. Its core component is micro-electromechanical system (MEMS); This concept caused a great sensation at that time), and many sensors related to machinery can be integrated in this system.
At that time, KrisPister and others had an illusion-hanging a sensor chip on dandelion, the dandelion detected the signal wherever it flew, and then sent the signal back. Although this is only a hypothesis, some scientists really threw themselves into it with confidence and got the required data. For example, an aerodynamic expert has calculated the appropriate weight of the chip and so on. In 200 1 year, the laboratory of the University of California, Berkeley really made the prototype of this ideal chip, which is smaller than a grain of rice and can be described as "as thin as a hair and as thin as a cicada". They gave me one, and I wrapped it carefully. Unfortunately, I can't find it recently, which is a great pity. If there is still electricity in the chip, maybe I can locate it through the internet.
During this period, three universities and research institutions took the lead in the field of sensors. One is the University of California at Berkeley (represented by KrisPister, who put forward the theory of "smart dust"), and the other two are the University of California at Los Angeles (they put forward "micro wireless technology") and the XeroxPARC alto Research Center. The team of Xerox Palo Alto Research Center is mainly led by me. We are engaged in sensor information processing and "SmartMatter", hoping to put computing and micro-motor systems into the physical world, which is also closely related to "smart dust".
Since the beginning of this century, people have paid more and more attention to the study of sensing. Many schools and R&D institutions of large companies have begun to conduct similar research, and many emerging companies have sprung up. Connecting sensors into a "network" or "system" becomes a sensor network. In addition to sensor networks, similar concepts have been put forward, such as "CyberPhysicalSystem" and "InternetofThings" (IOT for short). Relatively speaking, the concept of IOT is closer to daily life in the early days, such as the common RFID (Radio Frequency Identification) technology is one of them.
Regarding the history of sensor networks and Internet of Things, sensor networks should have been born for 30 years. However, it should be only 15 to 20 years away from the micro-sensor network: the micro-sensor network began in the 1990s, when people just put forward the concept of "micro-motor system", trying to integrate all sensors and computer processing and communication on one chip, that is, "intelligent dust".
In fact, the history of sensors comes down to eight words-from small to large, from point to surface. These eight words seem simple, but they are difficult to do-if the sensor really "flies into the ordinary world", it must "slim down" in terms of volume, cost and energy consumption before it can really enter the physical world.
However, the restoration of modeling is not the only condition for sensing to enter life, but also the cooperation of internet technology to realize point-to-point internet connection. As far as IP address is concerned, the Internet of Things should adopt IPv6(IPv4 is definitely not enough), and it has 128 binary IP addresses, which is equivalent to giving every grain of sand in the world an IP address. Only when all objects have their own IP can the Internet of Things be truly realized. In short, the realization of the Internet of Things needs these two aspects to complement each other: first, using micro-manufacturing technology to improve integration; The second is to use IP technology to provide enough rich websites.
4.3 Problems faced
There are many problems in the domestic smart home market. 1, the entry threshold is high, and the general one-time investment is 1 and 20,000 yuan, which greatly limits the purchase demand of people below middle income. 2, the function is flashy, many of them are remote control of a sound and light, and the demand and input are out of proportion. 3, copy mechanically, copy a lot of industrial things directly into the family, lack of humanization, can not fully meet the needs of home life. 4. Many smart home enterprises lack core technologies, patchwork and form a system promotion, which leads to higher costs and lower competitiveness.
The application of RFID UHF technology in China is still in its infancy, and the application of some projects is only a pilot, which has not been widely used or applied in the supply chain. For example, it is only used in a warehouse, or it is only used in the production line. It should be said that these pilot projects are all
All of them belong to closed-loop applications, and the case of serial application in supply chain has not appeared in China.
The development potential of the Internet of Things is infinite, but the realization of the Internet of Things is not only a technical issue. The construction process of the Internet of Things will involve many issues such as planning, management, coordination and cooperation, standards and security protection, and a series of corresponding supporting policies and norms need to be formulated and improved.
The first is the issue of technical standards. Standard is a communication rule, which is related to the communication between Internet of Things items. Different countries have different standards, so it is necessary to strengthen cooperation between countries in order to find a universally accepted standard.
Second, security issues. Articles in the Internet of Things are more closely linked, and articles and people are also linked together, which makes information collection and exchange equipment widely used, and data leakage has become an increasingly serious problem. How to protect a large amount of data and users' privacy has become an urgent problem.
Third, the issue of agreement. The Internet of Things is an extension of the Internet, which is based on the core layer of TCP/IP. However, at the access level, there are various types of protocols, such as CPRS, SMS, sensor, TD-SCDMA, wired, etc., and the Internet of Things needs a unified protocol foundation.
Fourth, the terminal problem. In addition to its own functions, IOT terminals also have functions such as sensors and network access, and different industries have different requirements. How to meet the diversified needs of terminal products is a big challenge for operators.
Fifth, the address problem. Everything in the Internet of Things needs to be addressed, so it needs an address. The Internet of Things needs more IP addresses, and IPv4 resources are about to run out, so it needs IPv6 to support it. The transition from IPv4 to IPv6 is a long process, so once the Internet of Things uses IPv6 address, there will inevitably be compatibility problems with IPv4.
Sixth, the cost problem. At present, the cost of chips and other components required by the Internet of Things is relatively high. If all items are implanted with identification chips, it will naturally cost a lot of money. How to effectively solve this problem still needs to be considered.
Seventh, the issue of scale. Scale is an important indicator of operators' performance. Terminal price, product diversity, and the depth and breadth of industry applications will all affect the scale of users. How to achieve scale is a problem to be discussed.
Eighth, the business model. The business model of Internet of Things in business application is not very clear, and it is worth further discussion.
Ninth, the industrial chain problem. The upstream technologies and industries such as automatic control, information sensing and radio frequency identification required by the Internet of Things are mature or basically mature, while the downstream applications also exist in a single form. The development of the Internet of Things needs the concerted efforts of the industrial chain to realize the linkage of upstream and downstream industries and interdisciplinary linkage, so as to drive the whole industrial chain and promote the development of the Internet of Things.
To establish an effective Internet of Things, there are two major difficulties that must be solved: first, scale, only with scale can the intelligence of goods play a role; Second, mobility, goods are usually not static, but in a state of motion, so it is necessary to keep the goods in motion, even at a high speed, and monitor and track them at any time.
To realize the Internet of Things, we must first embed electronic tags and other storage bodies in all items, and install many reading devices and huge information processing systems, which will inevitably lead to a large amount of capital investment. Therefore, under the premise that the cost is not reduced to universal, the development of the Internet of Things will be limited. All the facts have proved that the technical efficiency of the Internet of Things has not been transformed into economies of scale at this stage, and none of the so-called Internet of Things applications have achieved great success in business. For example, intelligent meter reading system can transmit the readings of electric meters to the data center of power system through commercial wireless system (such as GSM short message), but this technology has not been widely used in power system because it is not economical and efficient.
The key of the Internet of Things lies in RFID, sensors, embedded software, transmission data calculation and other fields, including "cloud computing" and the expansion and optimization of wireless networks, which are all problems to be solved in the popularization of the Internet of Things. Only through the application of "cloud computing" technology can the real-time dynamic management of hundreds of millions of commodities become possible. Judging from the current domestic industrial development level, the sensor industry is at a low level, and high-end products are monopolized by foreign manufacturers.