A brief analysis of Internet of Things technology for public safety monitoring

introduction

With the continuous deepening of the research on the concept, connotation, technology and application of the Internet of Things, many typical cases of the application of the Internet of Things have emerged in the fields and industries of environment, electricity, logistics, public safety, etc. Among them, the public safety field, as a key field of the application of the Internet of Things, has different characteristics and a special status from other Internet of Things applications. It is necessary to conduct in-depth research on the application of the Internet of Things in the public safety field (hereinafter referred to as the secure Internet of Things) as an independent concept.

1 Background and connotation of secure IoT

At present, China is in a period of rapid industrialization and urbanization. Various traditional and non-traditional, natural and social risks and contradictions coexist, and the situation facing public security and emergency management is more severe. There are mainly three problems: 1) Natural disasters are in a period of frequent occurrence. In recent years, extreme climate events have occurred frequently, and medium-strong earthquakes have been active. The suddenness and harmfulness of natural disasters and their derivative and secondary disasters have further increased; 2) The safety production situation is severe. my country's safety production foundation is weak. Some local governments and enterprises have not fulfilled their responsibilities and have not implemented supervision. The total number of production safety accidents remains high, and major accidents occur from time to time. The task of preventing accidents and implementing effective rescue is heavy and arduous; 3) Social security faces new challenges. my country's reform and development has entered a critical stage. Various interest relations are complicated and the task of maintaining social stability is arduous.

Faced with frequent public safety accidents that cause large numbers of casualties and property losses, there is an urgent need to build a public safety monitoring Internet of Things to perceive public safety hazards and solve problems such as how to interconnect various departments after an emergency occurs.

The Internet of Things for public safety monitoring is an information system project consisting of a perception layer, a network layer, and an application layer. It is built by applying Internet of Things technology, especially sensor network technology, to target the public safety monitoring field, which has a wide coverage, many monitoring indicators, high continuity requirements, an environment that is not suitable for manual monitoring, and the perceived information content is closely related to the lives of the people. The monitoring of public safety mainly includes monitoring to ensure the safety of various production scenarios, monitoring the safety of producers, monitoring the safety of specific items, monitoring crowded places, monitoring important equipment and facilities, and collecting information on scenes, people, and items during emergency response to accidents.

2 The role of secure IoT in the development of IoT

Public security is the cornerstone of national security and social stability. In order to effectively resist the threats of various man-made or natural disasters, China will strengthen public security measures as a key focus of government work. The public security monitoring Internet of Things provides a new way to solve the public security problems facing my country, which is in line with my country's strategic requirements to promote scientific and technological innovation and take the path of innovative national development.

Establishing a sound public safety monitoring Internet of Things will provide a practical and effective prevention mechanism for the safety issues that my country is currently facing, such as bridge and tunnel collapses and dangerous goods leakage. The interconnection of public safety monitoring Internet of Things across the country will enable major safety incidents to be resolved in a timely, effective and transparent manner. Therefore, as the Internet of Things application in the field of public safety that is most closely related to daily life and is of greatest concern to the country and the people, the public safety monitoring Internet of Things should be given attention and priority development by the entire society. Adhere to the principle of "government-led, enterprise participation, social support, and mass benefit", and promote the progress of the Internet of Things in technology, application, industry, and standards through the development of the public safety monitoring Internet of Things, so that the entire society can personally feel the advantages of the public safety monitoring Internet of Things in the reliable prevention of public safety hazards and emergency response to emergencies, and enhance people's awareness of the value of the Internet of Things.

3 Architecture and key technologies of secure IoT

Figure 1 describes the network architecture of the public safety monitoring Internet of Things. Its overall architecture is similar to that of the Internet of Things, consisting of three parts: the perception layer, the network layer, and the application layer. However, due to the particularity of the application scenario of the public safety monitoring Internet of Things, it has some technical features that other Internet of Things applications do not have, which are summarized as follows:

1) At the perception layer, the types of information being perceived are diverse and require high real-time performance. The perception of most information (such as the safety status of bridges and buildings, monitoring of dangerous goods, etc.) requires high precision and is difficult to detect by manual means. Due to the high uncertainty of the types of information on potential safety hazards, a large number of different types of sensors should be deployed for a long time in crowded places or high-risk production sites, which puts higher requirements on the networking strategy, energy management, transmission efficiency, QoS, sensor coding, address, frequency and electromagnetic interference of the perception layer. These issues are also the key to the mature application of the public safety monitoring Internet of Things.

2) At the network layer, since the information perceived by the public security monitoring Internet of Things involves key national industries and the daily lives of the masses, once this information is leaked or used improperly, it may endanger national security, social stability and the privacy of the people; therefore, it is necessary to transmit the information content of the public security monitoring Internet of Things through a dedicated network or after taking security precautions on the 3G mobile network to ensure the security, authenticity and integrity of the information.

3) At the application layer, in order to address the serious hazards that may be caused by massive amounts of data and security risks, it is necessary to establish dedicated public security IoT service platforms of different levels. The service platform should not only have powerful information processing and integration capabilities, but also have the ability to identify and warn of security risks. At the same time, when public security incidents occur, it should promptly link up with relevant functional departments for emergency response, and strive to minimize losses and impacts. In addition, interconnecting public security IoT platforms of different levels is conducive to maximizing the allocation of resources according to the degree of harm caused by security incidents, and facilitates the timely, effective and transparent resolution of public security incidents.

Figure 1 Public safety monitoring IoT architecture

According to the characteristics of the public safety monitoring Internet of Things architecture, the key technologies involved are mainly:

a Research and development of special sensors for public safety monitoring, including increasing the types of monitoring information of sensors, improving monitoring accuracy, reducing size, resisting damage, and enhancing the anti-interference and confidentiality capabilities of perceived information.

b. Perception layer network technologies such as self-organizing networks of large-scale sensor nodes, collaborative sensing technology, and secure access technology.

c Issues such as coding, addressing, frequency allocation and electromagnetic interference of large-scale sensor nodes.

d Network layer: the structure, communication protocols, heterogeneous network access technology and network security technology of the public safety monitoring dedicated network.

The e application layer mainly involves technologies such as intelligent processing, analysis, and integration of massive information and the architecture of a unified public safety monitoring Internet of Things service platform.

Figure 2 describes the overall structure of the public safety monitoring IoT service platform. The system platform processes and analyzes the massive amount of information received and then processes it through the corresponding service modules. The service platform can add different service modules according to different public safety monitoring applications. The public safety incident emergency response department linkage system is responsible for mobilizing resources for emergency management in a timely manner when sudden safety incidents occur, so as to reduce losses and impacts.

Figure 2 Overall structure of the public safety monitoring IoT service platform

4 Application Status of Secure IoT

There are already many application cases of public safety monitoring IoT at home and abroad, which have played a significant role in the field of public safety, such as:

Material Technologies, a US company, has developed a crack diagnostic sensor system that has been used to check cracks on three bridges in Pennsylvania and one in Massachusetts. Its sensors can detect cracks that expand at a rate of several molecules per minute, thereby detecting cracks that could pose a safety hazard several years in advance. In addition, early diagnosis means that road repair crews can perform repairs more economically because it is easier to repair cracks when they are still small.

In order to protect the lives and property of citizens and curb crime, terrorist attacks, and fires, South Korea has begun to install sensor systems in potential safety areas within the city. Many attempts have been made to ensure the safety of citizens and build safe cities, as shown in Figure 3.

Figure 3 Application of public security IoT in urban security

At present, the Xuanwu Lake Tunnel, with a total length of about 2.66 kilometers, is the largest shallow-buried open-cut lakebed tunnel in my country, of which the lakebed section is about 1.66 kilometers long. Due to the complex geological conditions, stress conditions, and environmental influences, the tunnel is likely to be affected by factors such as temperature, load, and groundwater, resulting in uneven settlement, lateral cracking, and water seepage.

The Optoelectronic Sensing Engineering Monitoring Center of Nanjing University "implanted" special continuous distributed optical fibers into the concrete layer. From the beginning of construction until the opening to traffic, these optical fibers have been monitoring the "health" of the tunnel in real time.