Discussion on planning solutions for smart light poles in fully enclosed highway scenarios

0. Introduction

As the basic carrier and sensing terminal of the new smart city, the smart pole is oriented by "Beautiful China, Digital China, Smart Society" and requires the construction of a "resource-saving, environment-friendly" society and new smart city. The basic purpose is to save land, energy and raw material consumption, protect the urban environment and ecological landscape, reduce duplication of construction, and improve infrastructure utilization. With poles and common poles as the core and carrier, on the basis of realizing smart lighting and green lighting, it selectively integrates communications, municipal administration, environmental protection, public security, transportation, urban management and many other fields. Intelligent sensing equipment realizes the integration of multiple functions such as charging piles, wireless communications, video surveillance, streaming media, emergency alarms, environmental monitoring, parking detection, manhole cover and water accumulation monitoring, public broadcasting and information interaction. It combines industrial design with Internet of Things technology to meet functional needs while paying attention to the harmony of the ecological environment. It has miniaturization, aesthetics, concealment and powerful composite functions, thereby maximizing resource utilization, providing healthy, applicable, efficient, convenient and harmonious coexistence infrastructure for the city, and fully supporting the construction of new smart cities.

1. The inherent advantages of smart light poles as 5G base station carriers

Smart light poles integrate wireless base stations, Wi-Fi equipment, sensors, video surveillance, RFID, public broadcasting, information release and other types of sensing equipment on the basis of street light poles. Like the nerve endings of the city, they can fully collect, publish and transmit information to form a smart sensing network, which can realize many applications such as smart lighting, smart security, wireless cities, smart sensing, smart transportation, smart municipal administration, etc.

The industry has reached a consensus on the future 5G network architecture: 5G must be a heterogeneous multi-layer network, and ultra-dense networking (UDN) has become an inevitable development trend of 5G networking. The essence of ultra-dense networking is to double the frequency reuse efficiency through quantitative changes in the density of micro base stations deployed per unit area, thereby meeting the thousand-fold capacity growth demand of 5G. Therefore, the application of 5G micro base stations will become more common. It is expected that the number of micro base stations will reach more than 10 times that of 4G networks, which will be a huge challenge for 5G network deployment.

Looking at the world, in the planning and construction of smart cities, smart light poles have become a key application field of the Internet of Things in cities because of their advantages of electrification, networking, and wide distribution. They also pay attention to the aesthetic appearance while meeting the application functions. These characteristics coincide with the supporting needs of 5G micro-station construction.

2. Planning solutions for smart light poles in fully enclosed highway scenarios

Urban road lighting is an important part of urban public facilities. With the advancement of urbanization, the number of urban road lighting street lamps is increasing. At the same time, smart light poles have also begun to be installed on fully enclosed highways and equipped with smart lighting, video surveillance, 5G base stations, WIFI, emergency broadcast and other intelligent communication and sensing equipment systems to achieve multi-pole integration, integrating big data, Internet of Things, artificial intelligence and other emerging technologies to monitor and release traffic conditions, safety hazards, weather disasters and other information in real time to build smart highways.

2.1 Issues that need to be paid attention to when planning smart light poles in highway scenarios

(1) "Shadow" problem of road lighting

1) "Shadow" of lighting between longitudinal street lights

Due to unreasonable design, the spacing between lamps is too large or the maximum illumination angle of the light distribution curve along the road is too small, resulting in too low illumination between lamps. In this way, the road surface will be "bright and dark", which brings a lot of visual fatigue to driving.

2) "Shadow" between horizontal street lights

Due to unreasonable design, the height of the light pole and the elevation angle of the lamp are not enough, or the maximum illumination angle of the light distribution curve of the lamp along the road is too small, resulting in too low illumination in the center of the road, which will also bring a lot of inconvenience to driving.

The way to solve the above lighting "shadow" problems is mainly based on the basic rules of lamp spacing and lamp height, road width and lamp height in road lighting design, and then combined with the light distribution curve of lamps to layout the lamps.

(2) Illumination problem on fully enclosed highways

The main problem that highway lighting needs to solve is how to enable the driver to quickly and accurately receive necessary visual information (such as whether there are obstacles on the road, the relative position of the front and rear vehicles, speed, road brightness and linear shape, etc.) when the car is driving at high speed at night, so that it can respond in time to prevent traffic accidents due to insufficient sight distance in advance and increase the sense of security and comfort when driving at night. However, there is an important problem in common lighting design, which is the waste of resources caused by excessive illumination. We know that expressways are fully closed roads with no pedestrians or non-motorized vehicles. Except for key sections and bridges where the illumination can be appropriately increased, other locations do not require too high illumination to meet the needs of safe driving.

The best way to solve the above illumination problems is to choose smart light poles equipped with intelligent lighting systems and capable of dynamically adjusting illumination.

(3) Smart light pole 5G micro base station site selection planning

As the most widely distributed and densest municipal facilities, smart light poles can meet the site requirements of 5G ultra-dense networking. The distance between street light poles is generally between 20 and 30 meters, and the site distance of 5G micro stations is required between 100 and 200 meters. Each light pole integrates a 5G system. The number of street light poles can fully meet the site construction needs of three telecom operators.

The construction of smart light pole 5G base stations needs to be combined with the layout of surrounding base stations, comprehensively consider the needs of operators, and plan the layout reasonably. It is recommended to reserve a smart light pole every 200 meters for use by telecommunications companies. Since communication operators have their own independent communication networks, they only need to provide optical fiber to the comprehensive computer room, and use the power terminals provided by the smart light poles for power supply.

(4) "Multiple regulations into one" planning issue

Smart light pole planning involves government departments' urban and rural control planning, land and space planning, etc. With the preparation of the current "14th Five-Year Plan" and the adjustment of other urban planning documents, it is necessary to consider the planning and deployment of smart light poles in a systematic and multi-level manner to avoid urban planning risks. In addition, since smart light poles contain many cross-field and cross-professional functional modules, involving the planning of functional modules such as 5G, video surveillance, and smart transportation, it is necessary to comprehensively consider the technical characteristics and standards of different functional modules, combined with urban regional differences and development characteristics, and have a certain forward-looking awareness to integrate them into the urban planning system.

(5) Obtaining basic data

The data that needs to be processed for smart light pole planning involves a wide range of data, including not only basic databases such as urban geographical status map layout, planning layout, urban building layout, pipe gallery distribution status and planning, but also information on construction projects of different departments or enterprises, construction standards and technical indicators of each functional module, information security, etc. Therefore, the preparation unit needs to have in-depth communication with the planning leading department at the beginning of the planning stage, obtain more basic data within the scope of the law, and obtain the approval of the planning leading department, so as to avoid the delay of the planning project due to basic data factors in the later stage.

2.2 Difficulties in the design of smart light poles in fully enclosed highway scenarios

(1) Sky design

Base station equipment is generally installed on the upper part of smart light poles. The calculation of the load-bearing load of the pole needs to consider the equipment size, installation space, windward area and specific installation form of the equipment. In order to make the environment harmonious and beautiful, 5G equipment generally needs to be camouflaged as necessary, most of which will be achieved by adding a beautifying cover. The pole load calculation mainly considers the windward area of ​​the beautifying cover.

The wind load calculation of smart poles should comply with the requirements of the current building structure load specifications. The calculation of wind load should consider the windshielding area of ​​other accessories such as pole components, antenna equipment, lighting equipment and functional equipment, and the ground roughness should be determined based on the area where the pole tower is located.

The windward area and weight of commonly used equipment are shown in the table below:

Table 2.1 The windward area and weight of commonly used equipment

At the same time, the specific weather conditions and geological conditions of the project location need to be combined with the calculation and design based on the "Design Standards for Towering Structures", "Design Standards for Building Foundations", "Steel Structure Design Standards" and other standards.

(2) Cabling design

The wiring of the base station equipment should be laid from inside the smart light pole body. The types of cables that need to be connected to the equipment in the equipment cover at the top of the pole include power cables, optical fibers, MON interface cables, grounding wires, etc. The number of cables is determined based on the number of deployed devices. At the same time, cabling holes need to be reserved at the interface flange at the top of the pole.

(3) Power supply design

Base station equipment requires 24-hour power supply. Since the power supply time and load capacity of base station equipment are different from other pole-mounted equipment, a separate power supply should be provided for the base station equipment and the power supply capacity should not be less than 2000W. There are currently two relatively mature power supply solutions for base station equipment: one is centralized remote power supply, which is mainly suitable for power supply of AC base station equipment; the other is -48V local power supply, which is mainly suitable for power supply of DC base station equipment. Both power supply methods have their own advantages and disadvantages. Centralized and remote power supply facilitates the centralized acquisition of mains power, reduces the number of power systems, and facilitates unified construction and management, but the line loss is large and increases operating costs; -48V local power supply requires the introduction of outdoor -48V power supply. The equipment is small and flexible in installation, but each base station needs to independently introduce mains power. The power introduction cost is high, the power supply equipment is decentralized, the initial construction cost is high, and daily maintenance management is cumbersome.

(4) Transmission design

Transmission is divided into wired transmission and wireless transmission. Wired transmission signals are stable, but there are line limitations during use, and the flexibility is relatively poor. Wireless transmission is highly flexible and has certain convenience, but it is susceptible to interference from other factors during use.

When smart light poles use wired transmission, a splice box needs to be configured at the bottom of each light pole. The optical fiber requirements for the introduction of optical cables for 5G equipment deployed on smart street lights are generally 2 to 6 cores. Considering the reservation for other services, it is recommended to lay out 12-core or 24-core introduction optical cables. When smart street lights use wireless transmission, the transmission equipment is generally deployed above the 5G equipment. At this time, smart light poles must also consider the load increase caused by the installation of wireless transmission equipment, and conduct calculations and designs based on relevant standards and specifications for pole design based on the meteorological conditions and geological conditions of the project location.

(5) Lightning protection and grounding design

Each smart light pole needs to be equipped with a lightning protection grounding system. The design of the pole grounding system can be implemented with reference to the relevant standards and specifications of the "Communications Bureau (Station) Lightning Protection and Grounding Engineering Design Specifications". The equipment and the pole body can share the grounding system, and a grounding bar is set inside the equipment beautification cover at the top of the pole.

2.3. Construction key points of smart light poles in fully enclosed highway scenarios

(1) Since most expressways are in closed and independent viaduct sections, the construction of smart light poles must meet the relevant requirements for high-altitude operations. For example, materials used in construction must be stacked smoothly and not hinder traffic, loading and unloading. Tools should be placed in the tool bag; walkways, channel boards and climbing equipment during operation should be cleaned at all times; disassembled objects and remaining materials and waste materials should be cleaned and transported away in time, and should not be randomly littered or discarded downwards. It is prohibited to throw objects while passing them.

(2) During the construction process, relevant highway construction regulations must be implemented, regular construction safety education should be carried out, and the "speed mark diagram" should be improved, that is, 500 meters, 1000 meters, 1600 meters of construction ahead, signboards, traffic zones, roads becoming larger and smaller, construction signs for cars, and detour warning posts. At the same time, construction must be carried out within the red line, and warning and highway warning slogans and signs must be set up. Closed access signs and closed road speed signs must be erected on adjacent roadsides before construction can begin.

(3) All personnel entering the construction site should wear safety helmets and luminous clothing. Personnel working at heights above 2 meters where reliable protective facilities cannot be used must wear seat belts. Personnel engaged in electrical welding operations must use masks or goggles. Special operators must hold certificates to work and wear corresponding labor protection supplies.

3. Conclusion

As one of the new infrastructures of smart cities, smart light poles are in a period of accelerated construction. We should give full play to the guiding role of planning in the construction of smart cities, seize the wave of the new generation of information technology revolution, complete forward-looking, scientific and operable planning, meet the needs of the era of "Digital China, Smart Society", and improve urban planning and construction capabilities and modern governance capabilities.

References

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