Application of 4G LTE Modem in Traffic Signal Control: Which Option for Low-Latency Communication? Unlock New Solutions for Traffic Scenario Optimization
In today's era of accelerated urbanization, traffic congestion has become a core pain point restricting urban development. According to statistics, the average speed of vehicles on congested road sections during morning and evening rush hours in China's first-tier cities is less than 20 kilometers per hour, and the economic losses caused by traffic delays account for 1.5% to 2.5% of GDP. As the "nerve center" of urban traffic management, traffic signal control directly affects road traffic efficiency through its response speed and decision-making accuracy. With breakthroughs in 5G and Internet of Things technologies, low-latency 4G LTE modems (data transmission units) are becoming key devices for reconstructing traffic signal control systems, providing core support for the construction of smart transportation.
1.Low-Latency Communication: The "Lifeline" of Traffic Signal Control
1.1 Why is Low Latency a Necessity?
The essence of traffic signal control is a real-time decision-making system. When a vehicle is traveling at 60 kilometers per hour, every 100 milliseconds of delay may cause the vehicle to travel an additional 1.67 meters, easily triggering a chain reaction in dense traffic. Traditional signal control systems rely on wired networks or 4G communication, with delays generally exceeding 300 milliseconds, making it difficult to meet the needs of complex scenarios. Low-latency communication technologies (such as 5G) can compress delays to within 10 milliseconds, achieving the following breakthroughs:
?Emergency Response: When a traffic accident or pedestrian intrusion occurs at an intersection, the system can adjust the traffic lights within 0.1 seconds to prevent secondary accidents.
?Vehicle-Infrastructure Coordination Control: Real-time interaction with autonomous vehicles enables "green wave passage," reducing sudden braking and starts and stops, and improving traffic efficiency.
?Dynamic Timing Optimization: Dynamically adjust the traffic light cycle based on real-time traffic flow, such as extending the green light time on main roads and shortening the waiting time on side roads during morning rush hours.
1.2 The Practical Value of Low-Latency Technology
Take a pilot project in a certain city as an example. After deploying low-latency 4g lte Modems, the average passage time at intersections was shortened by 23%, the congestion index decreased by 18%, and tailpipe emissions were reduced by 15%. More crucially, the system can support multi-modal data fusion—processing data from cameras, radars, geomagnetic sensors, and other devices simultaneously, achieving a closed loop for the entire process of "perception-decision-making-execution." For example, when a camera detects that a bus is about to enter the station, the system can extend the green light time of the bus lane in advance to ensure priority passage for the bus.
1.Core Application Scenarios of 4G LTE Modem in Traffic Signal Control
2.1 Real-Time Control of Intersection Traffic Lights
Traditional traffic lights adopt fixed timing plans and cannot adapt to real-time traffic changes. By deploying 4G LTE modems, a distributed intelligent control system can be constructed:
?Edge Computing Nodes: The 4g lte Modem is equipped with an edge computing module that can process sensor data locally, reducing cloud transmission delays. For example, the USR-DR154 supports Modbus TCP/RTU protocols and can directly connect to geomagnetic sensors to collect real-time traffic flow data.
?Multi-Protocol Conversion: It is compatible with protocols of devices from different manufacturers (such as OPC UA and MQTT), enabling "heterogeneous device interconnection." For example, converting the RS485 interface of old traffic lights to IP protocol for integration into the new system.
?Remote Operation and Maintenance: Through the 4G/5G module of the 4g lte Modem, operation and maintenance personnel can remotely modify the timing parameters of traffic lights without on-site operations, reducing maintenance costs.
2.2 Vehicle-Infrastructure Coordination (V2X) System
Vehicle-infrastructure coordination is the core direction of future transportation, with real-time communication between vehicles and infrastructure at its heart. The 4G LTE modem plays the role of a "data transfer station" in this scenario:
?Low-Latency Transmission: It supports 5G Cat.1/Cat.4 modules to ensure that the data interaction delay between vehicles and roadside units (RSUs) is less than 20 milliseconds. For example, when an autonomous vehicle approaches an intersection, the 4g lte Modem can transmit real-time information such as traffic light status and pedestrian positions to assist the vehicle in decision-making.
?Multi-Device Access: It can simultaneously connect to cameras, radars, lidars, and other devices to achieve "multi-source data fusion." For example, the USR-DR154 supports dual-channel MQTT protocols and can transmit data to two cloud platforms (such as traffic command centers and vehicle enterprise platforms) simultaneously.
?Security Protection: It is equipped with built-in SSL/TLS encryption and two-way certificate verification to prevent data tampering or interception and ensure the security of vehicle-infrastructure communication.
2.3 Traffic Flow Monitoring and Prediction
Traffic flow prediction is the basis for optimizing traffic lights. 4G LTE modems can connect to various traffic flow monitoring devices to build a big data analysis platform:
?Real-Time Data Collection: It can connect to geomagnetic sensors, radar speed detectors, etc., through RS485/Ethernet interfaces to collect data such as traffic flow, vehicle speed, and lane occupancy.
?Cloud Collaborative Analysis: The data is uploaded to cloud platforms (such as Alibaba Cloud and Huawei Cloud), and AI algorithms are used to generate prediction models. For example, predicting the traffic flow at a certain intersection in the next 15 minutes to adjust traffic light timing in advance.
?Visual Monitoring: Through the 4g lte Modem's HTTP/WebSocket protocols, the data is pushed to a monitoring large screen to achieve "one-map" management. For example, a traffic command center in a certain city uses the USR-DR154 to display the status of intersections across the city in real time and supports drag-and-drop timing adjustments.
1.Cellular Modem USR-DR154: An "All-Round Player" for Low-Latency Traffic Signal Control
Among numerous 4G LTE modem products, the USR-DR154 launched by USR IoT has become the preferred solution for traffic scenarios due to its low latency, high reliability, and easy deployment. The following are its core advantages:
3.1 Ultra-Low-Latency Communication
?5G Cat.1 Module: It has a theoretical downlink rate of up to 10Mbps and a latency of less than 50 milliseconds, meeting the real-time requirements of vehicle-infrastructure coordination.
?Dual-Channel MQTT Protocol: It supports simultaneous connection to two cloud platforms (such as traffic command centers + vehicle enterprise platforms) to ensure data redundancy backup.
?Edge Computing Capability: It is equipped with an independent hardware watchdog. Even if the network is interrupted, it can store data locally and automatically resend it when the network is restored.
3.2 Flexible Deployment and Operation and Maintenance
?WeChat Mini Program Configuration: By scanning the device QR code, parameters such as server address and subscription topic can be set up using the WeChat app on a mobile phone, eliminating cumbersome PC-end operations.
?Multi-Protocol Support: It is compatible with industrial protocols such as Modbus TCP/RTU, OPC UA, and SNMP, enabling seamless integration with existing traffic equipment.
?Remote Firmware Upgrade (FOTA): Device firmware can be updated without on-site operations, reducing operation and maintenance costs.
3.3 High-Reliability Design
?Industrial-Grade Protection: It supports a wide temperature range of -40°C to 85°C and an IP30 protection level, adapting to harsh outdoor environments.
?Power Redundancy: It supports dual power inputs and automatically switches to the backup power supply when the main power fails, ensuring continuous device operation.
?Security Encryption: It supports SSL/TLS 1.3 encryption and two-way certificate verification to prevent data theft or tampering.
Application Case:
The traffic department of a second-tier city deployed USR-DR154 4g lte Modems at 10 key intersections, connecting geomagnetic sensors and traffic light controllers. After the system went online, the average passage time at intersections was shortened by 18%, and the congestion index during morning rush hours decreased by 12%. Operation and maintenance personnel can remotely view device status through the WeChat mini program, and the fault response time was shortened from 2 hours to 15 minutes.
1.Customized Traffic Scenario Optimization Solutions: From Requirement Analysis to Implementation
To achieve deep integration of 4G LTE modems with traffic signal control systems, customized optimization solutions are required. The following are the key steps:
4.1 Requirement Analysis and Scenario Planning
?Define Objectives: Determine the optimization priorities (such as reducing congestion, improving bus priority, and ensuring pedestrian safety).
?Identify Pain Points: Analyze the problems with the existing system (such as high communication latency, poor device compatibility, and high operation and maintenance costs).
?Scenario Planning: Design differentiated solutions according to the type of intersection (such as cross intersections, T-junction intersections, and roundabouts).
4.2 Device Selection and Protocol Configuration
?4g lte Modem Selection: Select the appropriate model according to communication distance, data volume, and power consumption requirements (for example, the USR-DR154 is suitable for high-speed and low-latency scenarios; NB-IoT 4g lte Modems are suitable for remote and low-power consumption scenarios).
?Protocol Configuration: Unify the communication protocols between terminal devices, 4g lte Modems, and traffic light controllers (for example, prioritize the MQTT protocol due to its lightweight nature and low bandwidth usage).
?Edge Computing Deployment: Deploy edge computing nodes at intersections to achieve local data preprocessing and reduce cloud transmission pressure.
4.3 System Integration and Testing and Verification
?Integration Development: Develop data collection modules, protocol conversion middleware, and control instruction issuance interfaces to ensure smooth data flow between systems.
?Testing and Verification: Conduct functional testing (such as data collection accuracy and control instruction response speed), performance testing (such as system stability under high-concurrency scenarios), and security testing (such as data encryption strength and access control effectiveness).
?Simulation Exercises: Simulate scenarios such as morning and evening rush hours and traffic accidents in a test environment to verify the system's response capabilities.
4.4 Deployment and Launch and Continuous Optimization
?Phased Deployment: First conduct pilot projects in a small area (such as 2-3 intersections) to verify the feasibility of the solution before full-scale promotion.
?Operation and Maintenance Monitoring: Establish an operation and maintenance monitoring platform to view the running status of 4g lte Modems and traffic light controllers in real time and set abnormal alarm thresholds.
?Iterative Optimization: Continuously adjust traffic light timing strategies according to changes in traffic flow (such as holidays and construction road sections) to improve system adaptability.
1.Contact Us: Start a New Chapter in Smart Transportation
The deep integration of 4G LTE modems with traffic signal control is a core step in building a smart transportation system. Whether you aim to alleviate urban congestion, improve bus priority, or achieve vehicle-infrastructure coordination, we can provide you with customized low-latency communication solutions and traffic scenario optimization suggestions.
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