Header Compression Feedback for Wireless Packet Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication networks, the existing ROHC mechanism fails to effectively handle packet errors, leading to frequent state retreats and a drastic decrease in compression rate, especially when the packet error rate is high, resulting in wasted wireless network resources and reduced quality of service.
Innovation Solution
A method and apparatus that utilize feedback information from the retransmission mechanism to determine the state of the header compressor, allowing it to perform header compression based on the transmission state, thereby improving the reliability and efficiency of packet transmission by correlating the ROHC mechanism with automatic retransmission technologies like HARQ.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If header compression mechanism (ROHC) is used to reduce packet header overhead, then bandwidth utilization is improved, but packet transmission reliability deteriorates under high error rates
Solution Approach 1:
The patent introduces feedback mechanisms where the receiver sends acknowledgments and error information back to the transmitter. This enables the ROHC compressor to adapt its compression state based on actual transmission outcomes, improving reliability while maintaining bandwidth efficiency through dynamic adjustment of compression aggressiveness.
Solution Approach 2:
The patent implements dynamic state transition in the ROHC compressor, allowing it to move between different compression states (IR, FO, SO) based on transmission conditions. This dynamic adaptation enables the system to maintain high compression ratios when conditions are good while switching to more robust modes when errors occur, resolving the contradiction between compression efficiency and reliability.
2Loss of energy
If ROHC compressor operates in high compression state to save bandwidth, then bandwidth efficiency is improved, but system robustness against packet errors deteriorates
Solution Approach 1:
The patent applies preliminary actions by sending reference packets (IR packets) that contain complete header information before transitioning to high compression states. This prepares the decompressor with necessary context information in advance, enabling it to recover from errors more effectively while maintaining high compression ratios for subsequent packets.
Solution Approach 2:
The patent implements cushioning mechanisms by maintaining multiple compression states and allowing transitions to less aggressive compression modes when errors are detected. This beforehand cushioning provides a safety buffer that protects the system from complete failure under high error conditions while maintaining high efficiency during normal operation.
3Reliability
If retransmission mechanism is introduced to improve packet reliability, then transmission reliability is improved, but transmission delay increases
Solution Approach 1:
The patent implements skipping mechanisms where the receiver can operate with incomplete or partially corrupted header information by using previously stored context from the ROHC state machine. This allows the system to skip the retransmission step for certain packets and continue processing, reducing delay while maintaining reliability through selective recovery rather than universal retransmission.
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
A method for transmitting a header-compressed packet based on a retransmission mechanism is disclosed according to the present invention. The method mainly includes: a header compressor of a sending device obtains feedback information of a header-compressed packet in a transmission process; and the header compressor determines a state of the header compressor according to the feedback information, performs header compression for the packet according to the state of the header compressor, and sends the packet to a decompressor of a receiving device. According to the present invention, a header compression mechanism is combined with an automatic retransmission mechanism, so that the header compressor obtains feedback information of an automatic retransmission technology, and estimates the decompression information of the decompressor correctly, so as to change a state machine of the header compressor at proper time and improve transmission efficiency of the packet.