Timing Advance for Wireless Link Establishment Beyond 100 km
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Solution Overview
Problem
Air-to-ground (ATG) communication systems face challenges in establishing communication links between moving aircraft and ground stations, particularly when using modern telecommunications standards like 4G (LTE), as the maximum supported separation distance is limited, leading to failed connections beyond 100 km due to timing window constraints.
Innovation Solution
The system employs an antenna system with communication control circuitry that adjusts the timing of connection setup signals based on separation distance, applying a timing advance if necessary to ensure the signal is received within the identified timing window, and schedules sub-frames for uplink communication to avoid receive/transmit timing constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the connection setup signal is issued at the default time, then the timing procedure is simple, but the signal cannot be received within the identified timing window when separation distance exceeds the threshold
Solution Approach 1:
The system performs preliminary distance calculation between the aircraft and ground station before issuing the connection setup signal. Based on this pre-computed distance, the system determines whether to apply timing advance and calculates the appropriate advance value, ensuring the signal arrives within the timing window while maintaining procedural simplicity through automated decision-making.
Solution Approach 2:
The system dynamically adjusts the timing parameter of the connection setup signal based on the calculated separation distance. When the distance exceeds the threshold, the transmission time is advanced by a calculated amount, changing the temporal parameter to compensate for propagation delay and ensure reliable reception within the identified timing window.
2Length of stationary object
If the timing advance is applied to extend the communication range, then the connection can be established beyond 100 km, but the timing window constraint may be violated
Solution Approach 1:
The system uses feedback from the identified timing window information provided by the ground station to adjust the timing advance value. By monitoring whether the connection setup signal arrives within the timing window and receiving feedback on timing alignment, the system optimizes the timing advance to extend communication range while maintaining precision within the timing constraints.
Data Source
AI summary
A mechanism is provided for performing timing adjustment within a wireless communication system for a moving vehicle. The wireless communication system has an antenna system for communicating with a further antenna system, and communication control circuitry for performing a sign-on procedure to seek to establish a communication link with the further antenna system. During the sign-on procedure, the communication control circuitry issues via the antenna system a connection setup signal for receipt by the further antenna within an identified timing window. The wireless communication system also has location specifying circuitry for identifying a current location of the wireless communication system, and distance computation circuitry for obtaining location information specifying a location of the further antenna system, and for determining a separation distance between the antenna system and the further antenna system. The communication control circuitry is arranged to issue the connection setup signal at a default time unless the separation distance exceeds a setup threshold distance that indicates that use of the default time would prevent the connection setup signal being received within the identified timing window. In that event, the control circuitry instead applies a timing advance in order to issue the connection setup signal prior to the default time so as to cause the connection setup signal to be received by the further antenna system within the identified timing window. This facilitates successful establishment of a communication link even in situations where the separation distance between the antenna system and the further antenna system exceeds that supported by modern telecommunications Standards.