Key Issues and Implementation Pathways for Digital Low‑Altitude Infrastructure Construction Empowered by 5G‑A ISAC

Key Issues and Implementation Pathways for Digital Low‑Altitude Infrastructure Construction Empowered by 5G‑A ISAC

Research Authors: Buckhouse Intelligent Technology (Suzhou) Co., Ltd., Buckhouse Low‑Altitude Economy Research Institute, Buckhouse Global Low‑Altitude Economy Industrial Network, Buckhouse China Low‑Altitude Economy Industrial Network, Buckhouse International Low‑Altitude Economic Cooperation Network, Buckhouse Low‑Altitude Manufacturing Platform, Buckhouse Low‑Altitude Flight Platform, Buckhouse Low‑Altitude Support Platform, Buckhouse Low‑Altitude Infrastructure Platform, Buckhouse Low‑Altitude Industry Supporting Platform, Buckhouse Low‑Altitude Cross‑Boundary Integration Platform

Abstract

As a vital carrier of new‑quality productive forces, the low‑altitude economy has become an emerging industry prioritized for national cultivation. Digital low‑altitude infrastructure serves as the underlying foundation for large‑scale commercial operation of the low‑altitude economy. The traditional low‑altitude infrastructure system suffers from practical drawbacks including incomplete communication coverage, insufficient sensing capacity, fragmented multi‑source data, and high construction‑operation costs, failing to satisfy the demands of high‑density and wide‑area flight operations for massive UAVs and eVTOL aircraft. 5G‑A Integrated Sensing and Communication (ISAC) technology leverages one set of hardware and spectrum resources to deliver broadband communication, target detection, velocity measurement, angle measurement and positioning concurrently. It can reuse existing mobile communication base‑station sites to build an integrated digital low‑altitude base featuring “communication‑sensing‑navigation‑computing”, delivering a brand‑new technical paradigm for intensive construction of digital low‑altitude infrastructure. This report sorts out the technical connotation of 5G‑A ISAC and the development status of digital low‑altitude infrastructure. It analyzes key challenges in technical implementation, standard system, network networking, industrial business models and cross‑entity collaboration. Drawing on domestic pilot practices, it puts forward implementation pathways including hierarchical‑graded networking deployment, multi‑source sensing data fusion, iterative standard coordination, diversified business‑model innovation, scenario‑based pilot demonstration and safety‑risk control. It provides research references for high‑quality development of domestic digital low‑altitude infrastructure and sustainable growth of the low‑altitude economy.

Keywords: 5G‑A; Integrated Sensing and Communication; Digital Low‑Altitude Infrastructure; Low‑Altitude Economy; Low‑Altitude Intelligent Network; eVTOL

1. Introduction

1.1 Research Background

In recent years, China’s policy system for the low‑altitude economy has kept improving. The newly revised Civil Aviation Law of the People’s Republic of China has been formally implemented, and the classified‑graded management mechanism for low‑altitude airspace has been gradually rolled out. All 31 provincial‑level administrative regions have incorporated the low‑altitude economy into local development plans, bringing the low‑altitude industry into a new stage of legalized and systematic development. By the end of 2025, the total number of real‑name‑registered UAVs in China exceeded 3.28 million, with cumulative annual flight hours reaching 45.3 million. The market size of China’s low‑altitude economy keeps expanding. Industry institutions forecast that its overall market scale will surpass RMB 3.5 trillion by 2035.

Equipment manufacturing is undergoing rapid iteration. Heavy‑load UAVs and eVTOL manned aircraft continue to complete airworthiness certification. Application scenarios such as urban air mobility, low‑altitude logistics distribution, power‑grid inspection, emergency rescue and urban security are evolving from pilots to small‑scale commercial use, triggering explosive demand for digital low‑altitude infrastructure.

Digital low‑altitude infrastructure consists of six components: low‑altitude communication network, full‑domain sensing‑monitoring system, high‑precision positioning‑navigation network, low‑altitude flight service platform, vertical‑takeoff‑and‑landing supporting facilities, and computing‑data base. It undertakes core functions including aircraft network access and communication, target‑situation perception, flight‑mission scheduling, air‑situation management‑and‑control, as well as operation‑data storage and analysis, serving as a prerequisite for safe operation of low‑altitude aircraft.

In the past, low‑altitude monitoring mainly relied on traditional air‑traffic‑control radars, ADS‑B broadcasting and optoelectronic monitoring devices. Traditional radar equipment entails high costs and scarce site resources, with limited detection capability for “low‑slow‑small” targets. Optoelectronic devices are severely constrained by weather conditions such as rain, fog and darkness. ADS‑B is highly dependent on active reporting from aircraft and cannot effectively detect non‑cooperative “unauthorized flights”. The whole system features high construction costs and difficult deployment, making full‑scale urban‑wide coverage hard to achieve.

As a critical evolution phase of 5G, Integrated Sensing and Communication represents the landmark capability of 5G‑A. Leveraging large‑scale MIMO antenna arrays, it reuses communication signals as sensing signals. While delivering large‑bandwidth and low‑delay communication transmission for low‑altitude aircraft, it can detect and track the distance, velocity, angle and trajectory of low‑altitude targets. The single‑station sensing range can reach 1000‑1200 meters with sub‑meter‑level positioning accuracy. China’s three major telecom operators have carried out 5G‑A ISAC low‑altitude networking pilots in Beijing, Xiongan, Hangzhou, Hengqin and other locations, verifying the technical feasibility of ISAC in low‑altitude management‑and‑control and flight support scenarios, and opening up a new intensive‑construction path for digital low‑altitude infrastructure. Nevertheless, for large‑scale commercial roll‑out, 5G‑A ISAC‑enabled digital low‑altitude infrastructure still faces multiple practical constraints including technical bottlenecks, spectrum‑resource restrictions, inconsistent cross‑industry standards, great difficulties in network‑engineering implementation and unproven business models. It is urgent to clarify core contradictions and formulate replicable and promotable implementation pathways.

1.2 Research Significance

Theoretically, this report clarifies the technical coupling logic between 5G‑A ISAC and digital low‑altitude infrastructure, sorts out full‑chain key contradictions in digital low‑altitude infrastructure construction, enriches theoretical research on low‑altitude intelligent networks and digital low‑altitude bases, and provides references for subsequent academic research and standard formulation. Practically for industry, combined with domestic pilot cases, this report puts forward phased implementation pathways. It delivers decision‑making references for telecom operators, low‑altitude‑operation enterprises, local governments and equipment manufacturers in planning, project construction and business‑model design for new digital low‑altitude infrastructure, helping address the practical challenges of “detection, management and connectivity” in low‑altitude space and promoting large‑scale and sound development of the low‑altitude economy.

1.3 Domestic and International Development Status

1.3.1 Domestic Status

At the national level, the Guidelines for the Construction of Low‑Altitude Economy Standard System has been issued, explicitly proposing to accelerate the construction of low‑altitude communication‑sensing networks, promote the application of new technologies such as ISAC in low‑altitude‑economy scenarios, and encourage cross‑industry standard joint research between the telecommunications sector and civil‑aviation air‑traffic‑control sector. 3GPP has completed Phase‑1 technical standards for low‑altitude communication, and standards for 5G‑A ISAC keep iterating and improving. Domestic communication‑equipment manufacturers have developed and realized mass production of prototype ISAC base‑station equipment. The three major domestic operators are accelerating pilot network deployment: large‑scale 4.9G ISAC networking has been deployed in Yanqing, Beijing to complete multi‑UAV management‑and‑control tests; Xiongan New Area has built an ISAC low‑altitude network targeting airspace below 120 meters to achieve sub‑meter‑level positioning capability; urban low‑altitude ISAC networking tests have been conducted in Hengqin (Zhuhai), Hangzhou and other cities to test key commercial indicators including false‑alarm rate, missed‑detection rate and trajectory continuity.

On the industrial side, domestic low‑altitude flight service platforms are developing rapidly. Platforms such as China Telecom Tianyi Nebula and China Unicom Wotianyu have accessed ISAC sensing data into low‑altitude management‑and‑control platforms to realize aircraft‑trajectory tracking and electronic‑fence cross‑border alarms. Overall, however, domestic 5G‑A ISAC low‑altitude applications remain in the pilot‑demonstration stage. Large‑scale full‑domain networking cases are limited, equipment costs stay high, indicator systems of the telecommunications industry and civil‑aviation air‑traffic‑control industry have not been fully aligned, and commercial‑operation models are still under exploration.

1.3.2 International Status

European and American countries carry out research on sensing and communication‑network technologies targeting urban air mobility. The EU has incorporated communication‑sensing technologies into the technical roadmap for urban air mobility under the SESAR Programme. North America focuses on exploring broadband‑communication links for low‑altitude aircraft, mostly relying on dedicated aeronautical‑communication links. The roll‑out pace of cellular ISAC pilots lags behind China. Foreign solutions mainly focus on dedicated aeronautical communication and dedicated radars, with few practices of reusing public‑network base stations for ISAC networking, resulting in high overall construction costs and difficulty in large‑scale deployment. Globally, ISAC‑empowered digital low‑altitude infrastructure has not entered large‑scale commercial use, with numerous unresolved issues in technology, standards and business models.

1.4 Research Methodology and Framework

This report adopts literature research, industrial‑case analysis and technical‑comparative analysis. It sorts out open‑access policy documents, industry whitepapers, technical papers and public test data from pilots. Combined with multiple domestic urban low‑altitude ISAC networking pilots, it analyzes the internal mechanism of 5G‑A ISAC empowering digital low‑altitude infrastructure, identifies full‑chain key problems, and proposes implementation pathways from dimensions including technical research, standard development, network construction, data platforms, business‑model innovation and security governance. The research framework goes in the order: introduction, theoretical connotation of 5G‑A ISAC and digital low‑altitude infrastructure, value analysis of 5G‑A ISAC empowering digital low‑altitude infrastructure, analysis of key construction‑phase problems, implementation pathways, typical‑scenario practice, and conclusions & prospects.

2. Theoretical Connotation of 5G‑A ISAC and Digital Low‑Altitude Infrastructure

2.1 Core Technical Principles of 5G‑A Integrated Sensing and Communication

The core of 5G‑A ISAC lies in the sharing of hardware resources, spectrum resources and signal‑processing resources. One base‑station hardware device and one set of waveform signals simultaneously support communication services and radar‑sensing functions. On the communication side, it delivers large‑bandwidth, low‑delay and high‑reliability wireless‑communication links for low‑altitude aircraft to support UAV image‑and‑data transmission, eVTOL airborne‑service‑data backhaul and flight‑control‑command transmission. On the sensing side, the base station transmits wireless signals and receives target echo signals. It calculates target distance via time delay, obtains target azimuth via beam angle, and measures target velocity via Doppler effect to detect, track, measure velocity and direction for low‑altitude targets and output target‑trajectory data.

ISAC can achieve deep integration with BeiDou high‑precision positioning. ISAC base stations can be retrofitted into BeiDou CORS enhancement stations to build integrated “communication‑sensing‑navigation” capability, making up for positioning failures caused by satellite‑navigation signal blockage in urban‑canyon and high‑building‑occlusion scenarios and realizing continuous high‑precision positioning‑navigation for aircraft in complex urban environments. Two main technical routes are available: Sub‑6GHz ISAC and millimeter‑wave ISAC. The Sub‑6GHz solution delivers long propagation distance and strong coverage capability yet faces tight spectrum‑resource constraints. Millimeter‑wave boasts sufficient bandwidth and higher sensing precision yet suffers large propagation loss, requiring higher base‑station deployment density. The two routes have respective strengths and weaknesses for different scenarios. Large‑scale MIMO antenna arrays, integrated waveform design, multi‑station cooperative sensing, clutter‑suppression algorithms and multi‑source‑data fusion constitute core key technologies for ISAC.

2.2 System Architecture of Digital Low‑Altitude Infrastructure

Differentiated from physical facilities such as traditional physical take‑off‑and‑landing sites, digital low‑altitude infrastructure is new‑type infrastructure centered on digital networks, sensing and computing platforms. Its overall architecture is divided into terminal layer, network‑sensing layer, platform‑computing layer and application‑service layer.
‑ Terminal Layer: various UAVs, eVTOL manned aircraft, airborne communication‑positioning modules, as well as ground‑based optoelectronic and radar‑sensing equipment.
‑ Network‑Sensing Layer: the core of the base, including 5G‑A ISAC base stations, traditional low‑altitude radars, ADS‑B receiving stations and BeiDou ground‑based enhancement networks, undertaking communication transmission and full‑domain situational awareness.
‑ Platform‑Computing Layer: low‑altitude flight service platforms, air‑situation management‑and‑control platforms, big‑data and AI computing bases, responsible for convergence, cleaning, fusion and parsing of multi‑source sensing data, trajectory calculation, conflict‑alarm generation and task scheduling.
‑ Application‑Service Layer: oriented towards government regulatory authorities, aircraft‑operation enterprises and industrial clients, delivering services including air‑space management‑and‑control, flight‑approval processing, safety‑alarm notification and industry‑specific applications.

The core objective of digital low‑altitude infrastructure is to realize “clear detection, reliable connectivity, effective management and fast computation” for airspace below 300‑600 meters. It shall serve both regulatory authorities for low‑altitude‑safety governance and commercial low‑altitude operators by providing standardized public‑service capabilities.

2.3 Positioning of 5G‑A ISAC within Digital Low‑Altitude Infrastructure

Under traditional construction modes, the low‑altitude communication network and low‑altitude monitoring‑sensing network are independently planned and constructed, with separate procurement and installation of two sets of equipment. Site, power and transmission resources are repeatedly invested, leading to long construction cycles, huge overall investment and difficulties in large‑scale promotion. The biggest advantage of 5G‑A ISAC is the full reuse of existing mobile‑communication resources including sites, transmission, machine rooms and power‑supporting facilities. One single base station fulfills both communication and sensing functions to realize “one station for multiple purposes and one network for multiple functions”, greatly reducing hardware investment and site‑coordination costs for infrastructure construction. It serves as the core technical path for intensive construction of digital low‑altitude infrastructure.

Nevertheless, 5G‑A ISAC is not a replacement for traditional radar and optoelectronic detection equipment; instead, it forms complementary coordination with them. ISAC is suitable for wide‑area continuous coverage and continuous tracking of targets over broad areas. Traditional low‑altitude radars feature long detection range and strong detection capacity for key‑area major targets. Optoelectronic devices implement target image identification. The ideal pattern for the low‑altitude sensing system is a multi‑source‑fusion architecture of “5G‑A ISAC + dedicated radar + optoelectronics + ADS‑B”. Multiple types of sensing data converge into low‑altitude platforms to realize full‑target monitoring capability for both cooperative and non‑cooperative targets.

3. Core Value of 5G‑A ISAC for Digital Low‑Altitude Infrastructure Construction

3.1 Cost Reduction and Efficiency Improvement for Intensive Infrastructure Deployment

Building a brand‑new dedicated low‑altitude radar‑monitoring network requires large‑scale site coordination and supporting machine‑room‑and‑transmission facilities. Site‑resource acquisition within cities is extremely difficult with high overall construction costs. China has built a massive 5G base‑station network, with numerous sites distributed on urban high‑rises and poles, naturally adapting to deployment requirements for low‑altitude sensing. 5G‑A ISAC retrofitting can reuse existing site resources without massive new land and tower deployment. Sensing capability is superimposed on existing communication networks to reduce redundant construction, shorten construction cycles and significantly cut overall construction costs for digital low‑altitude infrastructure. It facilitates coverage extension to county‑level and township‑level regions and alleviates the current unbalanced pattern of “dense deployment in cities and sparse coverage in rural areas; dense deployment in hot‑spot zones and sparse coverage in ordinary zones” for low‑altitude infrastructure.

3.2 Concurrent Communication and Sensing to Support High‑Density Flight Operations

With the development of the low‑altitude industry, numerous UAVs and eVTOLs will operate simultaneously in future urban airspace. Aircraft need stable communication links for business‑data backhaul and flight‑control‑command reception, as well as continuous tracking by management‑and‑control systems. Under traditional schemes, communication networks and sensing systems operate independently. Data must be collected separately before time‑and‑space alignment, posing great challenges for data synchronization. 5G‑A ISAC base stations output communication‑service data and sensing‑trajectory data simultaneously with natural time synchronization, greatly lowering backend data‑fusion‑processing difficulty and supporting high‑density concurrent operation of massive aircraft in the same airspace to meet operational requirements of future urban air mobility.

3.3 Dual Support for Regulation and Industrial Services to Build a Public Digital Base

Low‑altitude situational data output by 5G‑A ISAC can be supplied to government air‑traffic‑control, public‑security and other regulatory departments to detect non‑cooperative unauthorized flights, generate cross‑border alarms and trigger low‑altitude‑safety‑risk early warnings, improving urban low‑altitude‑safety governance capacity. On the other hand, after desensitization and standardization, standardized service interfaces can be opened to low‑altitude‑operation enterprises, providing air‑situation and environmental‑sensing services for commercial flight entities engaged in logistics, inspection, cultural tourism and other sectors. One set of infrastructure undertakes dual values of public‑safety governance and industrial empowerment, improving comprehensive utilization efficiency of infrastructure.

3.4 Adaptation to Complex Urban Scenarios to Make Up for “Low‑Slow‑Small” Target Detection Deficiencies

In high‑rise‑dense urban environments, traditional radars suffer from building‑caused signal occlusion and numerous detection blind zones. Small consumer‑grade UAVs feature tiny radar‑cross‑section areas, posing high detection difficulty for traditional radars and easily triggering missed detections. With networking of widely distributed base stations, multi‑station cooperative detection of 5G‑A ISAC can compensate for single‑point detection blind zones, sustain monitoring of small low‑altitude targets in urban environments, and make up for capability deficiencies of traditional air‑traffic‑control facilities in urban low‑altitude‑space scenarios.

4. Key Issues in Digital Low‑Altitude Infrastructure Construction Empowered by 5G‑A ISAC

4.1 Key Technical Issues

4.1.1 Sensing‑Performance Deficiencies in Complex Urban Environments

High‑rise buildings in cities generate massive multipath‑reflection clutter. Building‑reflected signals produce false‑alarm targets and increase pressure on backend‑algorithm processing. Signal occlusion by buildings creates sensing blind zones, resulting in broken target‑tracking trajectories in partial areas and disabling continuous tracking. ISAC equipment delivers excellent performance in open‑suburb scenarios, yet in megacity downtowns with dense high‑rises, missed‑detection and false‑alarm rates still fall short of full commercial‑use requirements. Meanwhile, adaptive‑processing algorithms for detection thresholds targeting low‑altitude aircraft of varying sizes and materials require continuous optimization, and detecting small consumer‑grade UAVs remains technically challenging.

4.1.2 Technical Challenges in Dynamic Allocation of Communication‑Sensing Resources

Spectrum and power resources of one base‑station hardware need to be dynamically allocated between communication services and sensing services. Fluctuations in communication‑service traffic and variations in the number of sensed targets create resource competition. Excessive resource allocation for sensing will impair service experience for ground mobile‑communication users; priority given to ground communication will degrade low‑altitude‑sensing performance. Designing intelligent dynamic‑resource‑scheduling algorithms to balance ground public‑communication services and low‑altitude‑sensing services constitutes a practical engineering‑deployment challenge.

4.1.3 High Technical Barriers for Multi‑Station Cooperative Sensing and Multi‑Source‑Data Fusion

The detection range of a single ISAC base station is limited. Multi‑base‑station networking collaboration is mandatory for continuous air‑space coverage. Multi‑station time synchronization and spatial‑coordinate registration impose high requirements. Point‑trace data output from different base stations needs target association: when one aircraft is detected by multiple base stations simultaneously, duplicate targets must be eliminated. Moreover, ISAC‑sensing data shall be fused cross‑device with data from traditional radars, optoelectronic equipment and ADS‑B. Data formats, time granularities and precision indicators of different devices vary greatly. Data cleaning, target association and trajectory‑fusion algorithms feature high complexity, with numerous practical engineering problems pending resolution.

4.1.4 Great Engineering Difficulty for Integrated “Communication‑Sensing‑Navigation” Implementation

To construct a complete digital low‑altitude base, deep integration of communication, sensing and BeiDou high‑precision navigation is required. Integrating BeiDou CORS enhancement capability into ISAC base stations brings engineering challenges including hardware retrofitting, time‑synchronization and positioning‑solution computation. Under urban‑canyon scenarios with satellite‑signal occlusion, multi‑mode‑fusion‑positioning algorithms combining 5G‑A sensing‑positioning, inertial navigation and satellite navigation require continuous iteration to guarantee continuous high‑precision positioning for aircraft throughout flights.

4.2 Spectrum and Hardware‑Cost Issues

ISAC services impose high requirements on spectrum resources. The Sub‑6GHz band features favorable propagation properties suitable for wide‑area networking, yet existing spectrum resources are largely occupied by ground mobile‑communication services, bringing high spectrum‑coordination difficulty. The millimeter‑wave band provides sufficient bandwidth and favorable sensing performance yet suffers severe propagation loss. Continuous low‑altitude‑space coverage requires greatly increased base‑station deployment density, significantly raising equipment‑procurement and engineering‑construction costs. Currently, dedicated 5G‑A ISAC equipment customized for low‑altitude scenarios has not achieved large‑scale mass production, and per‑unit‑equipment costs remain high. Large‑scale full‑domain networking will incur huge overall investment, and equipment‑cost reduction depends on industrial‑scale expansion.

4.3 Cross‑Industry Coordination Challenges for Standard Systems

The telecommunications industry and civil‑aviation air‑traffic‑control industry belong to different industrial systems with divergent technical indicators, safety requirements and evaluation systems. The telecommunications sector prioritizes spectrum efficiency and network throughput; the civil‑aviation air‑traffic‑control system attaches paramount importance to flight safety with stringent requirements for detection reliability, missed‑detection rate and system availability. While 3GPP has finalized communication‑layer standards, standards for sensing indicators, data interfaces, data formats and safety‑reliability of ISAC targeting low‑altitude‑economy scenarios have not been fully unified. Huge cross‑industry‑standard‑alignment coordination work is required to specify how ISAC‑output low‑altitude‑sensing data can meet data‑access specifications of civil‑aviation regulatory systems, restricting technical deployment.

Meanwhile, numerous subdivided standards are still under research and formulation, including ISAC‑base‑station construction, network‑planning, testing‑evaluation and operation‑maintenance specifications, as well as standards for low‑altitude‑platform data security, data desensitization, interface opening and aircraft‑network interaction protocols. A complete standard system has not yet taken shape.

4.4 Practical Contradictions in Network‑Networking Engineering Construction

Original 5G‑base‑station planning and design target ground mobile‑phone users, with antenna beams mainly oriented downwards for ground coverage, rather than optimized for low‑altitude‑space ranging from tens to hundreds of meters. Direct reuse of existing base stations for low‑altitude‑sensing results in antenna tilt angles and beam shapes mismatched for low‑altitude‑space, leaving many sites insufficient sensing capacity for overhead airspace. Large‑scale antenna adjustment and hardware retrofitting will trigger massive retrofitting projects for existing base stations, with high difficulty in site‑property coordination and huge retrofitting workload. Building‑density discrepancies across cities lead to the absence of unified mature paradigms for network‑planning schemes for megacities, plain‑terrain cities and mountain‑type cities. Network‑planning models require continuous iteration and optimization oriented towards low‑altitude scenarios.

4.5 Data‑Governance and Platform‑System Issues

5G‑A ISAC networking generates massive raw low‑altitude‑target point‑trace and trajectory data. Full‑domain networking will produce enormous‑volume data, imposing pressure on storage, computing and bandwidth resources. Low‑altitude data involves public‑safety, air‑space‑management‑and‑control and corporate commercial‑flight data. Mechanisms for data classification‑grading, desensitization, data‑sharing boundaries and data‑privacy‑security protection have not been fully defined. Mature operational mechanisms are absent for data circulation among government regulatory authorities, telecom operators, low‑altitude‑platform enterprises and aircraft‑operation entities, including rules for data open‑access scopes and access‑permission management. Divergent data protocols for low‑altitude platforms built by different cities block cross‑city data circulation for cross‑city aircraft flights and constrain cross‑city flight‑service development.

4.6 Contradictions in Business‑Models and Industrial Ecosystems

Digital low‑altitude infrastructure features both public‑infrastructure attributes and industrial‑service attributes, with large upfront‑construction investment and long return cycles. Mature patterns for investment entities, paying entities and benefit‑distribution mechanisms have not been formed. Full reliance on government fiscal investment will impose heavy fiscal pressure for large‑scale construction. Reliance on market‑oriented investment by telecom operators encounters limited revenue from commercial scenarios in the early‑stage low‑altitude‑industry development, making rapid investment‑return difficult and dampening social‑capital‑participation motivation. Most current pilot projects are driven by project subsidies, with sustainable commercial‑closed‑loop mechanisms yet to be established, giving rise to the practical dilemma of “infrastructure ahead of industrial development”.

Insufficient collaboration exists across industrial‑chain links. Communication‑equipment vendors, telecom operators, civil‑aviation‑air‑traffic‑control authorities, aircraft‑manufacturing enterprises and low‑altitude‑operation enterprises lack sufficient joint coordination. Heavy adaptation‑and‑debugging workload exists among equipment, networks, aircraft and platforms, and a complete industrial ecosystem remains to be fostered.

4.7 Safety‑Risk‑Control Issues

5G‑A ISAC relies on wireless signals and faces security risks including wireless interference and signal spoofing. Malicious interference may trigger sensing failure and communication interruption, directly threatening low‑altitude‑flight safety. Cybersecurity protection for ISAC networks themselves to prevent network attacks from tampering with flight‑trajectory data constitutes another inevitable challenge. Furthermore, large‑scale deployment of low‑altitude‑sensing networks enables continuous detection of various overhead urban flying targets, bringing privacy‑security risks for air‑detection data. A comprehensive safety‑risk‑prevention‑and‑control mechanism must be established.

5. Implementation Pathways for Digital Low‑Altitude Infrastructure Construction Empowered by 5G‑A ISAC

Based on domestic industrial status and pilot‑practice experience, digital low‑altitude‑infrastructure construction shall adhere to the general principles of “pilot‑first strategy, hierarchical construction, multi‑source fusion, standard coordination, diversified investment and controllable safety”. A complete implementation pathway shall be constructed from seven dimensions: core‑technology research, standard development, network‑networking planning, platform‑data system, business‑model innovation, phased implementation and security governance.

5.1 Intensify Core‑Technology Research and Improve Multi‑Source‑Fusion Technical System

First, optimize ISAC clutter‑suppression and false‑alarm‑filtering algorithms targeting complex‑downtown urban scenarios. Conduct special‑algorithm optimization for high‑rise‑induced multipath interference to improve detection‑and‑tracking performance in dense‑urban‑area scenarios and reduce missed‑detection and false‑alarm rates. Develop multi‑station‑cooperative‑sensing algorithms and optimize multi‑base‑station point‑trace‑association and trajectory‑fusion algorithms to resolve duplicate‑target and trajectory‑breakage problems in multi‑station networking.

Second, research intelligent dynamic‑resource‑scheduling technology for communication‑sensing integration, realizing intelligent dynamic allocation of resources between ground mobile‑communication services and low‑altitude‑sensing services. Maximize low‑altitude‑sensing performance while ensuring no obvious deterioration of ground‑public‑communication‑service quality to achieve balanced performance for both categories of services.

Third, promote iterative upgrading of integrated “communication‑sensing‑navigation” technology, drive deep integration between ISAC base stations and BeiDou ground‑based enhancement, and optimize multi‑mode‑fusion‑positioning algorithms to address positioning‑drift problems under urban‑canyon‑occlusion scenarios and realize continuous high‑precision positioning for aircraft under complex conditions.

Fourth, uphold the multi‑technical‑route‑integration mindset. 5G‑A ISAC shall not function as a standalone solution. Build a multi‑source‑fusion‑sensing system of “5G‑A ISAC + low‑altitude radar + optoelectronic detection + ADS‑B”, leveraging respective strengths of different technologies. ISAC undertakes wide‑area continuous monitoring; radars deliver long‑distance detection for key targets; optoelectronic devices implement image‑identification verification. Multiple technologies complement each other to deliver all‑weather and full‑target monitoring capability, rather than relying solely on ISAC to resolve all low‑altitude‑sensing challenges.

Fifth, advance research‑and‑development of lightweight and low‑cost ISAC equipment. Develop low‑cost lightweight ISAC hardware for county‑level and township‑level regions, and reduce equipment‑procurement costs through large‑scale mass production to support wider‑scope promotion.

5.2 Promote Cross‑Industry Standard Collaboration to Build a Complete Standard System

Promote joint standard development among the telecommunications industry, civil‑aviation air‑traffic‑control industry and low‑altitude‑industry entities to break cross‑industry‑standard barriers.
First, improve technical‑indicator standards for 5G‑A ISAC targeting low‑altitude scenarios. Define core indicators including detection range, false‑alarm rate, missed‑detection rate, trajectory continuity and system reliability for low‑altitude‑scenarios, balancing technical capabilities of the telecommunications industry and civil‑aviation‑flight‑safety requirements.
Second, formulate unified data‑interface and data‑format standards. Standardize target‑point‑trace and trajectory‑data formats output by ISAC to ensure data output from equipment of different vendors can access various low‑altitude‑flight‑service platforms and resolve equipment‑interconnection‑and‑interoperability challenges.
Third, compile networking‑planning, engineering‑construction, testing‑evaluation and operation‑maintenance specifications for 5G‑A ISAC low‑altitude networks to provide standardized guidelines for engineering construction.
Fourth, improve standards related to data security, data desensitization and data sharing. Define classification‑grading of low‑altitude data, distinguish public‑safety data and corporate commercial‑business data, clarify data‑access permissions and desensitization rules, and strike a balance between regulatory‑safety demands and industrial‑data‑opening‑access requirements.

5.3 Adopt Hierarchical‑Graded Networking Planning for Scientific Network Construction

Abandon the idea of one‑step full‑domain‑coverage deployment. Carry out networking construction hierarchically following the principle of “priority for key‑area deployment, point‑to‑surface expansion and gradual scaling‑up”.
‑ Tier‑1: Prioritize construction of core pilot zones: urban core districts, airport peripheries, low‑altitude‑flight‑test zones, low‑altitude‑logistics‑operation zones and large‑event‑security zones. Prioritize 5G‑A ISAC‑network deployment in high‑risk and high‑frequency‑flight zones. For existing base stations, optimize antenna‑beam tilt angles and beam shapes according to site conditions to adapt to low‑altitude‑space‑coverage requirements. Prioritize retrofitting of high‑quality existing sites, prudently add new towers, and maximize reuse of existing communication‑infrastructure resources.
‑ Tier‑2: Expand industrial‑cluster zones: low‑altitude industrial parks, industrial zones and key county‑level towns. Gradually expand network coverage following business‑development progress of the low‑altitude industry.
‑ Tier‑3: Wide‑area peripheral zones. Deploy networks on‑demand in light of low‑altitude‑business‑development progress in townships, and avoid blind pursuit of one‑time full‑domain coverage.

Select technical routes distinguishing Sub‑6GHz and millimeter‑wave schemes: adopt the Sub‑6GHz solution for urban downtowns to balance coverage range and construction costs; superimpose millimeter‑wave ISAC equipment for small‑scale high‑security‑control key zones to obtain higher sensing precision. In the network‑planning phase, conduct channel‑simulation‑modeling combined with urban‑building height and landform features, scientifically plan base‑station‑site spacing and avoid blind large‑scale‑construction investment.

5.4 Build a Unified Base‑Platform and Improve the Data‑Governance System

Construct a digital low‑altitude integrated computing‑power platform as the data‑convergence hub for ISAC networks. The platform receives raw point‑trace‑and‑trajectory data output by 5G‑A ISAC networks, as well as multi‑source‑device data from radars, optoelectronic equipment and ADS‑B. It performs data cleaning, target association and trajectory‑fusion to generate a unified full‑domain low‑altitude‑situation view.

Improve the data‑governance mechanism and implement data classification‑grading: raw detection data related to public‑safety and air‑space‑management‑and‑control shall be mainly used by regulatory authorities. Service‑oriented data opened to commercial enterprises shall be desensitized to remove sensitive information, and air‑situation services shall be provided via standardized interfaces. Establish strict permission‑control systems with differentiated data‑access permissions assigned to different entities. Promote standardization of cross‑platform interfaces, explore regional‑level data‑interoperability mechanisms to support continuous data circulation for cross‑regional aircraft flights. Meanwhile, improve cybersecurity‑protection systems for platforms and implement network‑attack prevention and data backup to guarantee stable operation of low‑altitude‑platform systems.

5.5 Innovate Diversified Business Models and Build Sustainable‑Operation Mechanisms

In view of large‑investment and long‑return‑cycle characteristics of digital low‑altitude infrastructure, build a hybrid business model of “government guidance and multi‑entity participation”, avoiding sole reliance on fiscal investment or pure market‑oriented investment.

‑ Model 1: Co‑construction model combining special‑purpose government bonds and telecom‑operator participation. Local governments incorporate digital low‑altitude infrastructure into special‑purpose‑bond support scope for new‑type infrastructure and provide partial construction funds. Telecom operators invest in network equipment and site resources for joint network construction. Network services support government low‑altitude‑safety‑regulation demands on one hand, and charge fees for platform‑service and air‑situation‑service value‑added‑services targeting low‑altitude‑industry‑business entities on the other hand to generate long‑term operating revenue.
‑ Model 2: Investment‑construction‑operation‑in‑one model. Industrial consortia undertake project investment, construction and operation. Governments purchase basic public‑safety‑related services, while commercial value‑added‑services adopt market‑oriented charging for low‑altitude‑logistics, inspection and eVTOL‑operation enterprises.
‑ Model 3: Pilot‑project‑driven model. Centered on low‑altitude‑logistics and urban‑air‑mobility demonstration zones, deploy ISAC‑infrastructure on‑demand combined with specific landing projects. Drive infrastructure construction via business‑scenario development and avoid excessive large‑scale investment unsupported by business activities.

Meanwhile, explore diversified models including infrastructure franchise operation and industrial‑fund‑participated investment. Clarify the boundary between public attributes of infrastructure and commercial value‑added‑services. Basic air‑space‑safety‑regulation capabilities are opened as public‑services for regulatory authorities; advanced situation‑services and route‑scheduling‑services for commercial enterprises operate as value‑added‑businesses to gradually foster a sound commercial closed loop.

5.6 Phased‑Implementation Roadmap

‑ Phase‑1 (Pilot‑Verification Period): Focus on low‑altitude‑economy test zones in key cities. Complete small‑scale 5G‑A ISAC‑networking pilots, conduct technical verification, test end‑to‑end‑system performance under complex environments, polish equipment, algorithms and platforms, complete cross‑industry‑connection tests, accumulate engineering‑practice experience, and advance research and formulation of key standards simultaneously.
‑ Phase‑2 (Large‑Scale‑Promotion Period): In tandem with low‑altitude‑industry‑development progress, carry out large‑scale networking construction in key zones of a group of low‑altitude‑economy‑focused cities. Realize stable access of multi‑source‑sensing data into low‑altitude‑flight‑service platforms, form replicable construction schemes and business models, gradually implement relevant industry standards, and achieve equipment‑cost reduction via large‑scale mass production.
‑ Phase‑3 (Deep‑Popularization Period): Expand coverage to more cities, form a multi‑city‑collaborative national‑level digital low‑altitude‑infrastructure network. ISAC becomes a vital component of the digital low‑altitude base, business models mature, and it fully empowers large‑scale commercial‑application deployment of various low‑altitude businesses.

5.7 Improve a Full‑Dimensional Safety‑Risk‑Governance System

‑ Cybersecurity: Deploy full‑link safety protection for 5G‑A ISAC base stations, transmission networks and low‑altitude platforms. Implement network‑intrusion detection, access‑control and data‑encryption to guard against network attacks tampering with low‑altitude‑flight data.
‑ Wireless‑safety: Research wireless‑interference‑monitoring‑and‑identification technologies targeting ISAC systems, establish interference‑alarm‑disposal mechanisms to guard against flight‑safety risks caused by malicious wireless‑signal spoofing and interference.
‑ Data‑safety: Comply with data‑safety laws and regulations. Strictly control storage, utilization and circulation of raw low‑altitude‑detection data, implement data desensitization and guard against data‑leakage risks.
‑ Operational‑safety: Establish emergency‑disposal plans for system failures. When ISAC‑networks malfunction, rapidly switch to backup‑sensing means to ensure uninterrupted low‑altitude‑management‑and‑control services. Treat ISAC as an important rather than exclusive sensing means, and guarantee operational safety via multi‑source redundancy.

6. Analysis of Typical‑Application‑Scenario Practices

6.1 Urban Low‑Altitude‑Safety‑Regulation Scenario

Numerous small‑UAV flights in urban downtowns bring safety risks including unauthorized flights interfering with aviation and intrusions into sensitive zones. Supported by 5G‑A ISAC networking, continuous detection is conducted over urban airspace. It can receive identity‑and‑trajectory reports from cooperative aircraft and detect non‑cooperative unauthorized‑flight UAVs, output target trajectories, implement cross‑border alarms combined with electronic‑fence technology, and support disposal by public‑security and air‑traffic‑control regulatory authorities. The Yanqing (Beijing) pilot deployed ISAC base stations to realize UAV‑detection‑and‑tracking within designated zones and verify capability for urban‑security‑scenarios. Key construction priorities for this scenario include optimization of dense‑urban‑area algorithms and false‑alarm filtering to reduce invalid alarms for regulatory systems.

6.2 Low‑Altitude‑Logistics and Urban‑Air‑Mobility Scenario

Low‑altitude‑logistics‑distribution and future eVTOL manned‑operation impose high requirements for continuous communication guarantee and persistent aircraft monitoring. 5G‑A ISAC‑networks provide communication links for aircraft while continuously sensing aircraft‑operation trajectories. Data are accessed into flight‑service platforms for trajectory‑monitoring and conflict resolution to guarantee high‑density operation of multiple flight routes. This scenario demands high network‑latency‑performance and trajectory‑continuity of sensing, requiring deep integration between ISAC and BeiDou high‑precision positioning to build an integrated “communication‑sensing‑navigation” base.

6.3 Industrial‑Inspection and Emergency‑Rescue Scenario

UAVs for power‑grid inspection, river‑course inspection, forest‑fire‑prevention inspection and disaster‑emergency‑rescue often operate in suburbs and mountainous regions. Leveraging existing base‑station networks, 5G‑A ISAC delivers communication links for inspection UAVs and monitors aircraft‑flight status. Abnormalities such as UAV disconnection and yaw deviation can be rapidly detected. In disaster‑site scenarios, when public‑network base stations remain intact, ISAC‑networks can rapidly provide communication‑and‑sensing capabilities to support emergency‑rescue operations. Suburban scenarios feature minimal building occlusion, enabling superior ISAC‑sensing‑performance and serving as priority‑deployment targets.

6.4 Low‑Altitude‑Safety‑Guarantee for Large‑Scale Events

During large‑scale sports tournaments and public events, low‑altitude‑safety‑guarantee for event‑related airspace is required. 5G‑A ISAC can rapidly complete zone‑coverage and implement 7×24‑hour monitoring of event‑related airspace, timely detecting illegally intruding aircraft and fulfilling low‑altitude‑safety‑guarantee tasks. Relevant technical tests have been carried out for events such as the Harbin Asian Winter Games.

7. Conclusions and Prospects

Booming development of the low‑altitude economy generates urgent demands for digital low‑altitude infrastructure. Featuring unique integrated‑communication‑and‑sensing capabilities, 5G‑A ISAC technology can fully reuse existing mobile‑communication‑base‑station resources to realize multi‑purpose single‑station deployment. It delivers a brand‑new technical path for intensive construction of digital low‑altitude infrastructure, effectively making up for deficiencies of traditional low‑altitude‑monitoring systems and satisfying dual demands for regulatory governance and industrial development.

Nevertheless, for large‑scale commercial roll‑out, 5G‑A ISAC‑empowered digital low‑altitude‑infrastructure construction still faces multiple key challenges covering complex‑environment‑sensing performance, spectrum‑hardware costs, cross‑industry‑standard coordination, networking‑engineering retrofitting, data governance, business models and safety risks. ISAC shall not be regarded as an all‑purpose solution. It is mandatory to uphold multi‑technology‑integration thinking, achieve deep coordination with traditional radars, optoelectronic equipment and BeiDou navigation, follow the implementation route of pilot‑first and phased construction, strengthen cross‑industry joint‑standard‑development, continuously conduct core‑algorithm research, innovate diversified‑investment‑and‑operation models, and improve full‑chain safety‑governance systems.

Looking ahead, with continuous industrial maturation of 5G‑A, declining equipment costs and gradual improvement of cross‑industry‑standard systems, ISAC will be deeply integrated into the digital low‑altitude‑infrastructure base. It will keep iterating together with satellite‑ground‑integrated networks and 6G technologies, supporting steady and sound development of China’s low‑altitude‑economy industry and boosting the growth of new‑quality productive forces.

Data Sources

[1] Multiple ministries including Ministry of Industry and Information Technology, State Administration for Market Regulation. Guidelines for the Construction of Low‑Altitude Economy Standard System (2025 Edition)
[2] China Academy of Information and Communications Technology. Thoughts on Intensive Construction of “Communication‑Sensing‑Navigation‑Computing‑Air‑Control” Integrated Low‑Altitude‑Intelligent‑Network, Information and Communications Technology and Policy, 2026
[3] China Mobile Research Institute. 5G‑A Integrated Sensing and Communication Evaluation Methodology Whitepaper (2025)
[4] Civil Aviation Administration of China. 2025 Civil Aviation Industry Development Statistical Bulletin
[5] CCID Consulting. Research Report on China’s Low‑Altitude‑Economy Industry Development (2026)
[6] Telecommunications Science. Research on 5G‑A/6G + BeiDou “Communication‑Sensing‑Navigation” Integration Empowering the Low‑Altitude Economy, 2026
[7] ZTE Corporation. 5G‑A Integrated Sensing‑Computing‑Intelligence Fusion Technology Whitepaper
[8] Public pilot‑test data and public‑technology whitepapers from various telecom operators
[9] Local‑government‑issued low‑altitude‑economy‑related policy documents and open‑access special‑purpose‑bond information
[10] Open‑access academic literatures and 3GPP low‑altitude‑communication‑related technical reports

Disclaimer

This report is jointly compiled by Buckhouse Intelligent Technology (Suzhou) Co., Ltd. and its joint‑research platforms. All analyses, viewpoints and conclusions in this report are for academic‑research and industrial‑reference purposes only and do not constitute any suggestion for project investment, engineering construction or commercial‑operation decision‑making. Cited public‑data in this report are sourced from open‑access industry reports, government‑released documents and corporate‑public‑disclosure materials. The research team does not guarantee the absolute accuracy or completeness of third‑party original data. Partial contents of this report are subject to timeliness limitations due to rapid technological iteration and industrial‑environment changes. Without written permission from the research team, tampering, cropping or distorted dissemination of report contents is prohibited. Complete citation of report sources and research entities shall be implemented when quoting contents from this report. The viewpoints expressed in this report do not represent the official positions of any government department, equipment vendor or operator enterprise..................................................................................