What is the architecture of the Internet of Things? What protocols and standards are used? How to collect, process, transmit and receive information?

The English name of the Internet of Things is "The Internet of Things". As can be seen from the name, the Internet of Things is "the Internet where things are connected." This has two meanings: first, the core and foundation of the Internet of Things is still the Internet, which is an extension and expansion of the Internet; second, it extends to any user-end extension and any items. time for information exchange and communication. Therefore, the definition of the Internet of Things is to connect any item to the Internet through radio frequency identification (RFID) devices, infrared sensors, global positioning systems, laser scanners and other information sensing equipment according to agreed protocols for information exchange and communication. , a network that enables intelligent identification, positioning, tracking, monitoring and management.

The entire structure of the Internet of Things can be divided into two parts: radio frequency identification system and information network system. The radio frequency identification system mainly consists of tags and readers, which communicate through the 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 parsing, and then obtains various aspects of the product information through various interfaces of the EPC information service. related services. The operation of the entire information system will rely on the Internet network system and the communication protocols and description languages ??developed on the basis of 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 an application point of view, three levels in the Internet of Things deserve attention. In other words, the Internet of Things consists of three parts: First, the sensor network, which is mainly based on QR codes, RFID, and sensors to realize the detection of "things" identification. The second is the transmission network, which realizes data transmission and calculation through the existing Internet, radio and television networks, communication networks, etc. The third is the application network, that is, the input and output control terminal.

The EPC system is a very advanced, comprehensive and complex system. The ultimate goal is to establish a global, open labeling standard for every single product. As shown in Figure 2.4, it mainly consists of three parts: the global electronic product code (EPC) system, radio frequency identification system and information network system [17].

Figure 2.4 Structure diagram of the EPC system

(1) EPC coding standard

EPC coding is an important part of the EPC system. The relevant information is coded, and a global information exchange language is established through unified and standardized coding.

(2) EPC tag

EPC tag is a radio frequency tag loaded with product electronic code. Usually EPC tag is installed on the identified object and stores information related to the identified object. The information in the tag memory can be read/written non-contactly by the reader/writer.

3.2 EPC system characteristics

(1) Open architecture

The EPC system adopts the world's largest public TERNET network system. 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 greatest value of a network is that the system should be open to users and its structural system is far more valuable than complex multiple structures.

(2) Independent platform and high interactivity

The object recognized by the EPC system is a very wide range of entity objects. Therefore, it is impossible for one technology to be suitable for all Identify objects. At the same time, radio frequency identification technology standards in different regions and countries are also different. Therefore, the open architecture system 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 together with all possible components of the INTERNET network

(3) Flexible and sustainable development system

The EPC system is a flexible An open and sustainable development system allows system upgrades without replacing the original system. The overall EPC network operation relies on the intervention of RFID systems and network application systems to effectively disseminate product information.

Interpreters installed in different demand chain environments can read the product data stored in the tags. Therefore, supply chain data can be checked, updated or exchanged in a timely manner through the network.

3.3 EPC coding standard

EPC code is a new generation of coding standard compatible with EAN/UPC code. In the EPC system, EPC coding is combined with the current GTIN, so EPC is not Instead of the current barcode standard, the current barcode standard will gradually transition to the EPC standard or EPC and EAN in the future supply chain. UCC system *** deposit. The allocation of code segments in EPC is carried out by EAN. It is managed by UCC. In our country, EAN. The GTIN code in the UCC system is assigned and managed by the China Article Coding Center. Similarly, ANCC is about to launch EPC services to meet the needs of domestic enterprises for using EPC.

The EPC code is a set of numbers consisting of a version number plus three other pieces of data (domain name administrator, object classification, and serial number in order). The version number identifies the version number of the EPC, which allows the subsequent code segments of the EPC to have different lengths; domain name management describes the information of the manufacturer related to this EPC.

Chapter 4 Application of Internet of Things in Home

With the development of the times, China has gradually entered an aging society. In the future, the status quo our society will face will be a pair of young people. A couple, while taking care of their own children, also has to take care of 2 to 6 pairs of elderly people, which poses a problem for the whole society. It is obviously unrealistic for every family to hire a nanny; then, this problem can only be solved through technological means, by improving the quality of life of the family, facilitating information interaction between the family and the outside world, and using sensor nodes to sense what is happening at home, etc. This lays a social foundation for the realization of the home Internet of Things.

The concept of the Internet of Things is becoming popular, and it also allows people to see the future development trend of society. However, most of the Internet of Things remains in the conceptual stage, and it will take time for real-scale application. The home area is relatively small and the needs are relatively clear, so it is most likely to give priority to the application of the Internet of Things. It is not only a practical need of modern families (taking care of the elderly and children), but also people’s increasing family security

4.1 Application field of home Internet of Things

In the cold winter, the heating system uses Families in northern cities are full of warmth, and when most people leave home to go to work during the day, the empty rooms are still as warm as spring. We need an intelligent heating control system. In the field of production safety, in the field of food hygiene, in the field of engineering control, in the field of urban management, in all aspects of people's daily life, and even in people's entertainment activities, it is necessary to establish intelligent systems that can communicate with objects at any time. Through electronic tags (RFID) installed on various objects, sensors, QR codes, etc. are connected to wireless networks through interfaces, thereby endowing objects with intelligence, enabling communication and dialogue between people and objects, and enabling objects to communicate with each other. communication and dialogue. By installing sensors on the electricity meter, the power supply department can know the user's electricity consumption at any time, and realize efficient integrated management such as electricity inspection, power quality monitoring, load management, line loss management, and demand side management, reducing electricity losses over the past year. . Install sensors in the elevator. When the elevator fails, there is no need for passengers to call the police. The elevator management department will use the network to obtain information as soon as possible and go to the scene to deal with the fault as quickly as possible.

4.2 Development History

In 1999, the concept of the Internet of Things was proposed. In the past 10 years, countries around the world have been intensifying research. The development of the Internet of Things is divided into four stages: the first stage is the networking of mainframes and hosts, the second stage is the connection of desktops and laptops to the Internet, and the third stage is the connection of some mobile devices such as mobile phones. The fourth stage of the Internet is the rise of the embedded Internet. More application equipment closely related to people's daily lives, including washing machines, refrigerators, TVs, microwave ovens, etc., will join the ranks of interconnection, eventually forming a globally unified "Internet of Things" .

For the Internet, the 1980s was a golden age. During this period, a well-known figure emerged - Bob Kahn, who is known as the father of the Internet (known as the father of the Internet). There are several people who have been given the same title). While making outstanding contributions to the Internet, he also laid the foundation for another project that started in the 1980s - Distributed Sensor Network (DSN).

In those days, sensors were much larger than the one I have on hand and required a truck to pull them. Such large sensors are organized as nodes and connected to each other through microwaves to form a sensor network.

The size of the huge sensor cannot keep up with people's expectations for its functionality, so researchers began to think about whether they could make it smaller and smaller. Therefore, in the 1990s, the very interesting concept of "smart dust" emerged, proposed by KrisPister, a professor at the University of California, Berkeley. This concept believes that computing and communication can be integrated into ultra-miniature sensors of about 1 to 2 square millimeters to detect parameters of the surrounding environment. Its core component is a micro-electro-mechanical system (MEMS for short; this concept caused a great sensation at the time), which can integrate many mechanical-related sensors.

At that time, people like KrisPister had a fantasy - hanging a sensor chip on a dandelion, detecting the signal wherever the dandelion flew, and then transmit the signal back. Although it was just a hypothesis, there were scientists who invested in it with full confidence at that time and even calculated the required data. For example, aerodynamics experts have calculated the weight of the chip and so on. In 2001, the laboratory at the University of California, Berkeley, actually produced the prototype of this ideal chip, which was smaller than a grain of rice and could be described as "as thin as a hair and as thin as a cicada's wing." They gave me one and I packaged it carefully. It's a pity that I can't find it recently, which is very regrettable. If there is still electricity left in the chip, maybe I can locate its "resting place" through the network.

During this period, three universities and research institutions were leaders in the field of sensors. One was the University of California, Berkeley (represented by KrisPister, who proposed the "smart dust" theory), and the other two The first is UCLA (who proposed "microwireless technology") and Xerox PARC. The team at Xerox PARC is mainly led by me. What we do is sensor information processing and "smart matter" (SmartMatter). We hope to put computing and micro-motor systems into the physical world, which is also very similar to "smart dust". Close connection.

Since the beginning of this century, research on sensing has attracted more and more attention. Many schools and R&D institutions of large companies have begun to conduct similar research, and many emerging companies have taken advantage of this. A sudden rise. Connecting sensors into a "net" or "system" becomes a sensor network. In addition to sensor networks, similar concepts have also been proposed, such as "CyberPhysicalSystem" and "Internet of Things" (IOT for short). In comparison, the concept of IOT was closer to daily life when it was first proposed. For example, the common RFID (Radio Frequency Identification) technology is a part of it.

Regarding the history of sensor networks and the Internet of Things, if we start from the big sensors, it has been 30 years since the sensor network was born; and if we start from the MicroWireless Sensor Network, It should only be 15 to 20 years ago: micro-sensor networks began in the 1990s. At that time, people had just proposed the concept of "micro-electromechanical systems", trying to integrate sensors and computer processing and communication on one chip, that is, "Wisdom Motes".

In fact, the history of sensors can be summed up in eight words - from large to small, from point to surface. These eight words seem simple, but they are very difficult to implement - if you want the sensor to truly "fly into the ordinary world", it must be "downsized" in terms of size, cost, energy consumption, etc., so that it can truly Able to enter the physical world.

However, the reduction of shape is not the only condition for sensors to enter daily life. The cooperation of Internet technology is also needed to realize Internet connection from point to surface. As far as IP addresses are concerned, the Internet of Things should use IPv6 (IPv4 is certainly not enough). It has a 128-bit binary IP address number, which is equivalent to giving an IP address to every grain of sand in the world.

Only when all objects have their own IP can the Internet of Things be truly realized. All in all, the implementation of the Internet of Things requires these two aspects to complement each other: one is to use micro-fabrication to improve the level of integration; the other is to use IP technology to provide a sufficiently rich network.

4.3 Problems faced

There are many problems in the domestic smart home market. 1. The entry threshold is high. Generally, a one-time investment of 10,000 to 20,000 yuan is required, which greatly limits the purchase demand of people with lower middle income. 2. The functions are flashy, many of them are remote control lights and sounds, and the demand is not proportional to the investment. 3. Copying many things that were originally used in industry directly into the home lacks humanization and cannot fully meet the needs of home life. 4. Many smart home companies lack core technologies and patch together a system to promote it, resulting in increased costs and reduced corporate competitiveness.

The application of RFID ultra-high frequency technology in my country is still in its infancy. The applications of some projects are only pilot projects and have not been widely used, nor have they been applied in the supply chain. For example, only apply it in a certain warehouse, or only apply it on the production line. It should be said that these pilot projects are all closed-loop applications, and there have been no cases of applications in the supply chain in China.

The development potential of the Internet of Things is unlimited, but the realization of the Internet of Things is not just a technical issue. The process of building the Internet of Things will involve many issues in planning, management, coordination, cooperation, etc., as well as standards. and security protection issues, which requires the formulation and improvement of a series of corresponding supporting policies and norms.

The first is the issue of technical standards. A standard is a communication rule that relates to communication between IoT items. Countries have different standards, so cooperation between countries needs to be strengthened to find a standard that can be universally accepted.

The second is the issue of security. Things in the Internet of Things are more closely connected, and things and people are also connected, resulting in the extensive use of information collection and exchange equipment, and data leakage has become an increasingly serious problem. How to protect large amounts of data and user privacy has become a problem to be solved.

Third, the issue of agreement. The Internet of Things is an extension of the Internet. At the core level of the Internet of Things, it is based on TCP/IP. However, at the access level, there are various protocol types, such as CPRS, SMS, sensors, TD-SCDMA, cable and other channels. The Internet of Things needs a unified Basis of agreement.

Fourth, terminal problem. In addition to its own functions, IoT terminals also have functions such as sensors and network access, and different industries have different needs. How to meet the diverse needs of terminal products is a major challenge for operators.

Fifth, address issue. Every item that needs to be addressed in the Internet of Things needs an address. The Internet of Things requires more IP addresses, and IPv4 resources are about to be exhausted, so IPv6 is needed to support them. The transition from IPv4 to IPv6 is a long process, so once the Internet of Things uses IPv6 addresses, there will inevitably be compatibility issues with IPv4.

Sixth, the issue of cost. At present, the cost of chips and other components required for the Internet of Things is relatively high. It will naturally cost a lot to implant identification chips into all items. How to effectively solve this problem still needs to be considered.

Seventh, the issue of scale. Scale is an important indicator of operator performance. The price of terminals, product diversity, and the depth and breadth of industry applications will all have an impact on the scale of users. How to achieve scale is an issue to be discussed.

Eighth, business model issues. The business model of the Internet of Things in commercial applications is not yet clear, and the business model issue deserves further discussion.

Ninth, industrial chain issues. 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, and downstream applications also exist in a single form. The development of the Internet of Things requires the joint efforts of the industry chain to achieve linkage between upstream and downstream industries and cross-professional linkage, thereby driving the entire industry chain and jointly promoting the development of the Internet of Things.

To build an effective Internet of Things, there are two major difficulties that must be solved: one is scale, only with scale can the intelligence of items work; the other is liquidity, items are usually not static , but in a state of motion. Items must be kept in motion, and items can be monitored and tracked at any time even in high-speed motion.

To realize the Internet of Things, storage media such as electronic tags must first be embedded in all items, and numerous reading devices and huge information processing systems must be installed, which will inevitably lead to a large amount of capital investment. Therefore, the development of the Internet of Things will be limited before the cost is reduced enough to be popularized. Existing facts have proven that at this stage, the technical efficiency of the Internet of Things has not been transformed into economic efficiency of scale, and none of the current so-called Internet of Things applications has achieved great commercial success. For example, smart meter reading systems can transmit meter readings to the power system data center through commercial wireless systems (such as GSM short messages). However, the power system still does not use this technology on a large scale because it is not economically efficient.

The key to the Internet of Things lies in the fields of RFID, sensors, embedded software and transmission data computing, including "cloud computing", expansion and optimization of wireless networks, etc., which are all problems that need to be solved for the popularization of the Internet of Things. Only through the application of "cloud computing" technology can real-time dynamic management of hundreds of millions of types of items become possible. Judging from the current level of domestic industrial development, the level of personnel in the sensor industry is relatively low, and high-end products are monopolized by foreign manufacturers.