# A Multi-Layer Secure Sharing Framework for Aviation Big Data Based on Blockchain
## 3 Analysis of ATM Big Data Sharing
### ATM System Concepts
#### 3.1.2 ATM System Structure  
ATM is analyzed temporally and spatially, with data-sharing implications. Temporal dimension. The ATM system can be temporally divided into three distinct phases--strategic, pre-tactical, and tactical [23]--each exhibiting significant differences in functional implementation and data-sharing mechanisms. The strategic phase spans months to years, with core functions including airspace design and traffic flow prediction. By analyzing historical data and macroeconomic trends, this phase forecasts future traffic distribution and optimizes air route networks and sector configurations to accommodate long-term traffic growth. A representative example is the Dynamic Airspace Configurations (DAC) tool developed by Europe's SESAR project, which dynamically adjusts route networks and sectors by integrating multi-source data from various stakeholders including ANSPs, airline operators (AOs), airspace users (AUs), and network managers (NMs). Data shared during this phase encompasses airline flight plans, airport throughput capacity, airspace utilization metrics, and external socioeconomic data. The pre-tactical phase operates on timescales ranging from hours to days, focusing on establishing flow management strategies and dynamic route adjustments to address real-time variables such as adverse weather and temporary airspace restrictions. This phase requires sharing real-time operational data including aircraft performance parameters, live weather conditions, and current airspace status [1]. The FAA's System Wide Information Management (SWIM) exemplifies this through standardized interfaces enabling real-time data exchange between ATC, airlines, and airports, covering aircraft positions (ADS-B), meteorological radar data, and airspace status updates [23]. The tactical phase (operational layer) functions within minute-to-hour timeframes, emphasizing the execution of control instructions and conflict resolution under shared situational awareness. Controllers monitor operations in real time using surveillance technologies (ADS-B), issuing altitude and heading adjustments via voice communications (VHF) or data links (CPDLC), while coordinating with onboard collision avoidance systems (TCAS II) and the ground-based Short-Term Conflict Alert (STCA) to resolve aircraft conflicts. Tools like Electronic Flight Bags (EFBs) enhance situational awareness synchronization between pilots and controllers through features like route weather synchronization. In summary, the strategic phase primarily relies on cross-institutional historical data sharing and multi-source data fusion modeling to improve prediction accuracy. The pre-tactical phase achieves dynamic resource allocation through real-time data synchro  
Figure 1: Seven components of ATM system. nization and promotes collaborative decision-making (CDM) through multi-party data exchange. The tactical phase accomplishes situational awareness synchronization between controllers and pilots via immediate data sharing. This hierarchical data-sharing model across different time dimensions reflects the evolving operational requirements of ATM from macro-planning to micro-execution. * Spatial dimension. In terms of spatial architecture, air traffic management (ATM) constitutes a three-dimensional system that deeply integrates space-based (space), aerial (air), and ground (ground) components through multimodal communication technologies including satellite data links and aeronautical data links. The space-based system incorporates navigation satellites (GPS, GLONASS, Galileo, BeiDou, etc. ), communication satellites (Inmarsat, Iridium, etc. ), meteorological satellites (NOAA, Fengyun series), and space-based ADS-B (e.g., Aireon system). These collectively provide positioning/navigation, wide-area communication, weather monitoring, and transoceanic aircraft tracking capabilities. The aerial layer employs onboard data links such as ACARS and CPDLC to enable real-time trajectory management and dynamic airspace allocation.