Vehicle Relay Timing Assignment for Unsynchronized Communication Frames
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Solution Overview
Problem
Existing communication systems in vehicles lack an efficient method to assign transmission times to frames when the transmitting devices do not have the capability to do so, leading to inconsistencies and potential deviations in time synchronization.
Innovation Solution
A relay device mounted on a vehicle assigns a pseudo transmission time to frames based on reception time, using a processor and memory to determine and add the pseudo transmission time when the original transmission time is not assigned, ensuring consistent time synchronization across devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If transmitting devices do not have time synchronization or transmission time stamping units, then device complexity is reduced, but time synchronization accuracy deteriorates
Solution Approach 1:
The relay device acts as an intermediary that performs transmission time assignment on frames it relays. When the relay device receives a frame without an assigned transmission time, it determines the reception time and assigns this as the transmission time, thereby enabling time synchronization without requiring the original transmitting device to have time synchronization capabilities
Solution Approach 2:
The relay device creates a copy of the transmission time information by using the reception time as a substitute for the original transmission time. This copied time information is then attached to the frame, allowing downstream devices to perform time synchronization even though the original transmitting device did not provide accurate transmission time
2Measurement precision
If pseudo transmission time is assigned based on reception time, then time synchronization accuracy is improved, but device complexity increases
Solution Approach 1:
The relay device uses its own reception time as the basis for assigning transmission time to relayed frames. This self-service approach eliminates the need for complex coordination with external time synchronization systems, as the relay device independently provides the time assignment function using its own internal clock
3Reliability
If transmission time assignment is performed at the relay device, then communication reliability is improved, but processing time increases
Solution Approach 1:
The relay device performs transmission time assignment as a preliminary action when receiving the frame, before relaying it to the next device. By determining the reception time and assigning it as the transmission time at the moment of reception, the relay device ensures time synchronization is established in advance, improving communication reliability without adding significant processing delay
Data Source
AI summary
A relay device is mounted on a vehicle and relays a communication in a communication system of the vehicle. The relay device includes at least one of (i) a circuit and (ii) a processor with a memory storing computer program code executed by the processor, and the at least one of the circuit and the processor may be configured to: receive a frame transmitted from a first communication device; determine whether a transmission time of the frame is assigned to the frame; assign, as the transmission time, a pseudo transmission time, which is determined based on a reception time of the frame at which the frame is received, to the received frame when the transmission time is determined to be not assigned to the frame; and transmit the frame, to which the pseudo transmission time is assigned, to a second communication device.