Application of wireless technology in the Internet of things: RFID positioning system based on WiFi

1. Introduction

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 system, laser scanners and other devices with the Internet, Expand communication from the communication connection between anyone at any time and anywhere to the communication connection between people to things and things to things.

By embedding electronic labels, bar codes and other marks that can store object information on items, their real-time information is sent to the background information processing system through wireless network, and the major information systems can be interconnected to form a huge network. Thus, the purpose of intelligent management such as tracking and monitoring can be achieved. Generally speaking, the Internet of things can realize information communication between people and things.

2. Intelligent life in the era of Internet of things

Imagine an intelligent life in 2020.
At the weekend, Zhang San wanted to go for an outing. After getting on the bus, the car prompted that the tire pressure was abnormal. Zhang San went to the 4S store for maintenance. During the vehicle maintenance, Zhang San flashed in front of the coffee machine with his mobile phone. A cup of coffee that met Zhang San’s daily taste was ready. After enjoying the coffee, he received the signal that the vehicle has been repaired. During the outing, Li Si received Li Si’s invitation to play. Li Si sent the location of the stadium to Zhang San’s car, and the car automatically located to the stadium. When Zhang San arrived at the garage door, the parking lot of the stadium sent out the parking space navigation information and parked in the nearest parking space from Li Si’s location. After playing the ball, the car sends Zhang San’s home information to household appliances. Fifteen minutes before he gets home, the bathtub starts to store water, the microwave oven starts to cook, five minutes before he gets home, the air conditioner starts to start, and the garage door opens automatically 20 meters before the garage.
The industrial chain of Internet of things can be divided into four links: identification, perception, processing and information transmission. The key technologies of each link are RFID, sensors, smart chips and wireless transmission networks of telecom operators. The future development of the Internet of things will go through four stages. RFID will be widely used in logistics, retail and pharmaceutical fields before 2010. Objects will be interconnected from 2010 to 2015, semi intelligent from 2015 to 2020, and fully intelligent after 2020.

3. Perception and transmission of Internet of things

The Internet of things has a wide range of uses. It can be used in urban public safety, industrial safety production, environmental monitoring, intelligent transportation, smart home, public health, health monitoring and other fields, so that people can enjoy a safer and easier life.
For example, after driving from Shenzhen to Chongqing, you can sleep and watch movies as long as you set the destination. The on-board system will drive intelligently through the signals received on the road; If you don’t live in a hospital, as long as you use a small instrument, the doctor can monitor the patient’s temperature, blood pressure and pulse for 24 hours; After work, as long as you send an instruction with your mobile phone, the rice cooker at home will automatically heat and cook, and the air conditioner will start to cool down… This is not a scene in science fiction movies. Through the gradual realization and improvement of the “Internet of things”, everyone’s life will move closer to this. The so-called Internet of things, also known as sensor network in China, refers to a huge network formed by combining various information sensing devices with the Internet.
Specifically, the Internet of things refers to a new technology that connects various sensors with the existing Internet. By installing information sensing equipment, such as radio frequency identification (RFID) device, infrared sensor, global positioning system, laser scanner, etc., all items are connected with the network to facilitate identification and management. TV, washing machine, air conditioner, even bicycle, door lock and sphygmomanometer can be used.
From the perspective of application, the fields closely related to the Internet of things and may benefit mainly include QR code and RFID, sensors, TD-SCDMA and SIM card.
Internet of things applications can be divided into three layers:

• (1) Sensor network, which is mainly composed of two-dimensional code, RFID and sensors to realize the identification of “objects”;
• (2) Transmission network, even through the existing Internet, radio and television network and communication network to realize data transmission and calculation;
• (3) Application network, i.e. input / output control terminal, can be based on existing mobile phones, personal computers and other terminals.

In the “Internet of things”, RFID tags store standardized and interoperable information. They are automatically collected to the central information system through the wireless data communication network to realize the identification of items, and then realize the information exchange and sharing through the open calculator network to realize the “transparent” management of items.
In the Internet of things, the system application process is as follows:

• (1) Identify the object attributes, including static and dynamic attributes. The static attributes can be directly stored in the tag, and the dynamic attributes need to be detected in real time by the sensor first;
• (2) The identification device completes the reading of object attributes and converts the information into a data format suitable for network transmission;
• (3) The information processing of objects may be completed by the mobile communication center (such as the mobile communication center in China), or the information processing of objects may be completed by the mobile communication center, such as the mobile communication center in China.

4. Introduction to wireless communication technology

4.1 Bluetooth Technology

Bluetooth technology is an open global standard for wireless data and voice communication. Its essential content is to establish a general short-range wireless interface for the communication environment between fixed devices or mobile devices, and further combine communication technology with computer technology, so that various devices can be connected without wires or cables, It can realize mutual communication or operation in close range. The transmission rate of its 4GHz.1mbps frequency band is universal for the public all over the world.

4.2 WiFi Technology

Wi-Fi (wireless fidelity) is also a wireless communication protocol. Its official name is IEEE 802.11b. Like Bluetooth, it belongs to short-range wireless communication technology. Up to 11mb / Wi-Fi. Although it is worse than Bluetooth technology in terms of data security, it is slightly better in terms of radio wave coverage, up to about 100m. Wi-Fi is a wireless extension of Ethernet. Theoretically, as long as users are located in a certain area around an access point, they can access the web at a maximum speed of about 11mb / s. But in fact, if multiple users access through one point at the same time and the bandwidth is shared by multiple users, the connection speed of Wi-Fi will generally be only a few hundred KB / s, and the signal will not be blocked by the wall, but the effective transmission distance in the building is less than that outdoors.

4.3 UWB Technology

UWB (ultra wideband) is a wireless carrier communication technology. It does not use sinusoidal carrier, but uses nanosecond non sinusoidal narrow pulse to transmit data, so its spectrum range is very wide. UWB can transmit signals over a very wide bandwidth. The U.S. FCC stipulates that UWB occupies a bandwidth of more than 500MHz in the frequency band of 3.1 ~ 10.6GHz. Because UWB can realize high-speed data transmission by using low-power and low complexity transmitter / receiver, it has developed rapidly in recent years. It uses low-power pulses to transmit data in a very wide spectrum range without causing large interference to the conventional narrowband wireless communication system, and can make full use of spectrum resources. The high-speed data transceiver based on UWB technology has a wide range of applications.

4.4 ZigBee Technology

ZigBee is mainly used between various electronic devices with short distance and low data transmission rate. ZigBee’s name comes from the communication mode used by bees to survive and develop. Bees share the location, distance and direction of newly discovered food sources by dancing zigzag shaped dance.
ZigBee uses 2.4GHz band and frequency hopping technology. Compared with Bluetooth, ZigBee is simpler, slower, and has lower power and cost. Its basic rate is 250kb / s. when it is reduced to 28KB / s, the transmission range can be expanded to 134m and higher reliability can be obtained. In addition, it can be networked with 254 nodes. It can better support games, consumer electronics, instruments and home automation applications than Bluetooth. People expect to expand the application of ZigBee in the fields of industrial monitoring, sensor networks, home monitoring, security systems and toys.

4.5 IrDA Technology

IrDA (infrared data association) was founded in 1993. IrDA is a point-to-point communication technology using infrared. It is the first technology to realize wireless personal area network (Pan). The main advantage of IrDA is that there is no need to apply for the right to use the frequency, so the cost of infrared communication is low. It also has the characteristics of small volume, low power consumption, convenient connection and easy to use. In addition, the infrared emission angle is small and the transmission security is high.

4.6 dedicated wireless system

Private wireless system mainly includes some wireless systems with private frequency band and public frequency band, which are mainly used for data transmission or voice transmission. The systems used for digital transmission include wireless meter reading system, remote monitoring, etc; The systems used for voice transmission include wireless paging system, walkie talkie, etc. Systems with two functions at the same time, such as special security monitoring system for public security system.

5. Application of ZTE intelligent Wi-Fi technology in the Internet of things

5.1 introduction to Wi-Fi WLAN real-time positioning system

Real time positioning system refers to a system that locates the target in real time in a designated area (office building, site and urban area) through specific technology. It mainly uses radio frequency, ultrasonic, infrared and other technologies to locate the object. The traditional real-time positioning system solution of active RFID technology is facing the challenge from the solution based on wireless LAN (Wi-Fi). The RFID real-time positioning system based on Wi-Fi is developing rapidly abroad. According to the latest report, Wi-Fi technology accounts for more and more market share in the real-time positioning system related to RFID solution. The annual growth rate of Wi-Fi technology will exceed 70%, which has stronger market advantages compared with traditional active RFID technology.

5.2 product introduction of Wi-Fi WLAN real-time positioning system

The Wi-Fi WLAN real-time system consists of the following three parts:

• (1) Location tag (Wi-Fi tag);
• (2) Wireless LAN access point;
• (3) Locating server.

System working principle:

• (1) The positioning tag or wireless device sends wireless signals periodically.
• (2) After receiving the signal, the access point transmits the signal to the positioning server.
• (3) The location server judges the location of the tag or wireless device according to the strength of the signal or the time difference of signal arrival, and displays its specific location through an electronic map.

System functions:

• The visual terminal platform displays the position and moving track of people or objects in the form of electronic map;
• Indoor and outdoor real-time positioning with an accuracy of 3 meters;
• Playback and analysis of historical operation track.

Various automatic alarm mechanisms: deviation from preset operation track alarm; Warning of trespassing into the warning area; Tag power-off alarm; Tag disappearance alarm.
Active alarm mechanism: the label is equipped with an alarm button to realize active alarm.
Wireless sensing: real-time acquisition of temperature, humidity, parent density, pressure, vibration and other parameters. The server can set the parameter limit. If the limit is exceeded, an alarm will be triggered
The design of the whole system scheme runs through the principles of advanced technology, reasonable structure, mainstream products, low cost and low maintenance. Widely used in the market, involving various industries, tracking and positioning of hospital assets and personnel; Tracking and positioning of pallets and goods in the warehouse; Tracking and positioning of containers and trailers in the yard; Tracking and positioning of valuable tools and work in progress in the production and manufacturing workshop, dynamic attendance and management of workshop employees; Coal and oil field environmental monitoring and personnel tracking and positioning; Tracking and positioning of prison prisoners and security control; Tracking management of campus, community assets, security patrol, vehicles and foreign personnel; Tracking and positioning of assets and personnel in public places; Wi-Fi mobile phone and PDA tracking and positioning.

5.3 market application of Wi-Fi WLAN real-time positioning system

The demand for RFID real-time positioning system based on Wi-Fi in the Chinese market is very considerable. Potential demand mainly comes from the following aspects:

• (1) Safety management of hospital assets and personnel: foreign hospitals are rapidly adopting RFID positioning system based on WLAN. Domestic hospitals are also very concerned about this new trend. In the dynamic working environment of hospitals or medical institutions, the “low visibility” of assets and personnel often leads to a serious waste of time and resources, and even irreparable consequences. The RFID real-time positioning system based on Wi-Fi can track patients, staff and medical equipment in real time, and monitor the regional security and environmental conditions of valuable assets. The adoption of RFID real-time positioning system based on Wi-Fi in medical and health care institutions has a very large return on investment.
• (2) Container management: there are tens of millions of containers in China, and container transportation is the main artery of the economy. The vast majority of containers are very similar in shape, which is very difficult and laborious to find. Logistics and transportation companies often reserve a lot of containers for use, so that the vast majority of containers can not be used reasonably. On the one hand, there are too many containers, resulting in idle resources; On the other hand, we can’t find a suitable container, resulting in a shortage of resources, a waste of resources and an increase in costs. The RFID real-time positioning system based on wireless LAN can accurately grasp the location and status of containers in real time, realize the dynamic tracking management of containers, reduce the searching time of containers, and improve the utilization rate and transportation efficiency of containers; Prevent the loss, theft and damage of containers and their goods, reduce costs and increase revenue.
• (3) Production plant equipment and parts management: China has a large number of processing plants, which is the largest in the world. The RFID real-time positioning system based on Wi-Fi can automatically track the real-time distribution of WIP (including components, semi-finished products, finished products, etc.), tools, equipment and key personnel, accurately monitor and follow up management, and improve asset utilization and employee production efficiency. Some large factories, such as semiconductor factories and automobile manufacturers, can know the location of tools, equipment and parts at any time after using the wireless LAN positioning system, so as to reduce the search and waiting time and improve production efficiency.
• (4) Positioning of underground coal mine personnel: China is the largest coal consumer and producer in the world. With the rapid growth of the national economy, the demand for coal is rising. In the past two years, coal safety accidents have also occurred continuously. How to strengthen the preventive measures of safety production, how to change the current management mode of coal mining enterprises for underground personnel and backward assets, how to accurately, real-time and quickly perform the coal mine safety monitoring function, and ensure the efficient operation of rescue and disaster relief and safety rescue have become the concerns of all coal mining enterprises. The real-time supervision solution of coal mine personnel based on RFID real-time positioning system based on Wi-Fi can effectively strengthen the safety management of coal mine personnel, locate underground personnel in real time, intuitively and timely reflect the on-site situation and personnel status of coal mine, and improve the strength and efficiency of safety guarantee of coal mine personnel. It is a powerful tool for safety monitoring and management of coal mine personnel.
• (5) Logistics distribution management: the logistics industry has always been a typical application field of real-time positioning technology. With the rapid development of the logistics industry, wireless logistics will become the trend of logistics development in the future. A large number of pallets and trailers enter and leave the logistics distribution center every day, which requires a lot of manpower and material resources to manage these constantly moving assets, and manual operation is easy to lead to a lot of errors. After adopting the RFID real-time positioning system based on Wi-Fi, the positions of these pallets and trailers will be automatically recorded at any time. As long as you search on the electronic map of the system, you can find them immediately. In case of wrong placement, the system will alarm immediately.

6. Conclusion

Wi-Fi wireless sensor networks can use the existing Wi-Fi network resources to deploy and implement WSN, which will save a lot of hardware costs. In addition, without considering the interoperability with other devices, various other Wi-Fi devices emerging in the market increase the ease of use of this technology and help project implementers shorten the development cycle. In addition, the industry has accumulated rich network knowledge on Wi-Fi, which can be applied to WSN to maximize the benefits of return on investment (ROI) and total cost of ownership (TCO).
Other classified assets and personnel positioning management: in some places, such as schools, prisons, military, parks, etc., for personnel safety or other special purposes, it is often necessary to know the location, whereabouts and status of personnel at any time. In addition, for valuable and secret assets, it is often necessary to provide real-time monitoring and care. The RFID real-time positioning system based on Wi-Fi can be well applied to these positioning management, which can strengthen the security management of assets and personnel.
To sum up, Wi-Fi based RFID real-time positioning system is widely used. There is a huge demand for Wi-Fi based RFID real-time positioning system in many industries. Enterprises in the above-mentioned industries such as medical care, logistics and transportation, production and manufacturing, container transportation and coal mining may be our potential users. It is expected that the Internet of things will be another wave of information industry after computer, Internet and mobile communication network. Some experts predict that the Internet of things may be popularized on a large scale within 10 years, and this technology will develop into a trillion yuan high-tech market.

Source: China RFID Positioning Solutions Provider – Actility Technologies Company Limited (www.tractility.com)

Actility provides powerful security solutions for retail store management to prevent asset and property losses, improve transaction security, and provide intelligent analysis. We produce AM/EM/RFID systems, EAS tags, EAS soft tags, EAS safer, lanyards, detachers and all kinds EAS accessories products. Infrared people counter and camera people counter is available. If you want to have more information about the article or you want to share your opinion with us, contact us at [email protected]