Ground Device Dynamic Download Switching for Train Data
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Solution Overview
Problem
Conventional ground-onboard communication systems experience prolonged communication times, especially in regions with low wireless communication quality, due to the inefficiency of transmitting difference data across varying periods.
Innovation Solution
A ground device equipped with a difference-communication determiner that evaluates communication times for both batch and difference downloading methods, determining the optimal approach based on the ratio of already acquired data and the number of data divisions to minimize total communication time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If difference downloading is used to reduce data transmission amount, then data transmission efficiency is improved, but communication time increases when multiple difference data pieces are located in different periods
Solution Approach 1:
The system dynamically switches between difference downloading and batch downloading modes based on real-time evaluation of communication conditions, data characteristics, and network status. The determination unit selects the optimal downloading method by evaluating multiple factors including the time span of requested data, current network quality, and data change frequency, thereby resolving the contradiction between transmission efficiency and communication time.
Solution Approach 2:
The system changes the downloading mode parameter (from fixed difference downloading to variable selection between difference and batch downloading) based on evaluated conditions. When evaluation indicates that difference downloading would result in excessive communication time due to multiple time-period divisions, the system switches to batch downloading mode, thus adapting the parameter to resolve the contradiction.
2Loss of information
If data is acquired every time a request is received, then data freshness is improved, but data acquisition time becomes very long in regions with low wireless communication quality
Solution Approach 1:
The system performs preliminary evaluation of the requested data characteristics and communication conditions before executing data acquisition. By pre-assessing factors such as the time span of requested data, data change frequency, and network quality, the system determines the optimal acquisition strategy in advance, avoiding unnecessary sequential requests and reducing overall data acquisition time while maintaining data freshness.
Solution Approach 2:
The system dynamically adjusts the data acquisition strategy based on real-time conditions. Instead of always acquiring data on every request, the determination unit evaluates current needs and selects between difference downloading, batch downloading, or other strategies, thereby reducing acquisition time in poor network conditions while still providing timely data when needed.
3Productivity
If batch downloading is used to acquire all data at once, then communication frequency is reduced, but communication time increases when data amount is large
Solution Approach 1:
The system dynamically selects between batch downloading and difference downloading based on evaluation of data characteristics and communication conditions. When the requested data spans a long time period or exhibits high change frequency, the system determines that difference downloading is more efficient despite higher communication frequency, thereby resolving the contradiction between reducing communication frequency and minimizing communication time.
Solution Approach 2:
The system segments the data acquisition process into multiple targeted difference downloads rather than a single batch download when conditions favor this approach. By dividing the acquisition into smaller, focused requests for specific time periods or data types, the system reduces the communication time for each transaction while accepting increased communication frequency, thus resolving the contradiction.
Data Source
AI summary
An object is to obtain a ground device capable of reducing a communication time of train information from an onboard device to the ground device. A ground device, which is capable of communicating with an onboard device and acquiring unreceived data from the onboard device by difference downloading or batch downloading, includes a difference-communication determiner to determine whether to acquire the unreceived data from the onboard device by difference downloading or to acquire all data to be acquired from the onboard device including the unreceived data by batch downloading. The difference-communication determiner includes a communication-time evaluator to evaluate a total communication time when data in a specified period is acquired by the batch downloading and that by the difference downloading, and a communication switch to output a download instruction based on a result of evaluation by the communication-time evaluator.