Intermediate Node Cache Threshold for Fountain Code Data Streams
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multipath transmission systems face challenges in ensuring low-delay reliable data stream transmission due to network congestion, which requires complex closed-loop feedback mechanisms and additional network bandwidth, increasing implementation complexity.
Innovation Solution
The method involves using fountain codes for data streams, where intermediate nodes drop encoded packets when cache queue usage exceeds a threshold, ensuring reliable transmission without closed-loop feedback, thereby reducing network congestion and implementation complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If closed-loop feedback mechanism is used to monitor congestion situation on each path, then transmission reliability is improved, but implementation complexity increases and extra network bandwidth resource is occupied
Solution Approach 1:
The patent extracts the feedback mechanism from the system by using fountain codes that do not require acknowledgment packets or retransmission protocols. The encoding scheme itself provides error correction capabilities, eliminating the need for complex closed-loop feedback while maintaining transmission reliability.
Solution Approach 2:
The fountain code encoding provides self-service error correction capabilities at the receiver end without requiring feedback from the receiver to the transmitter. The receiver can reconstruct the original data from enough encoded packets received, making the system self-sufficient and eliminating feedback complexity.
2Loss of time
If closed-loop feedback control is used for congestion avoidance, then transmission delay is reduced, but network bandwidth resource is occupied and implementation complexity increases
Solution Approach 1:
The patent removes the feedback control mechanism entirely by using fountain codes with systematic encoding. The first k encoded packets contain all necessary information for reconstruction, eliminating the need for acknowledgment packets and retransmission requests that consume bandwidth and increase delay.
Solution Approach 2:
The fountain code encoding is performed in advance at the transmitter, creating k encoded packets that already contain all necessary information for reconstruction. This preliminary encoding action eliminates the need for real-time feedback control during transmission, reducing both delay and bandwidth consumption.
3Reliability
If retransmission mechanism is used to ensure transmission reliability, then packet loss is recovered, but transmission delay increases and implementation complexity increases
Solution Approach 1:
The patent uses disposable encoded packets that can be independently decoded. Each encoded packet contains redundant information, and the receiver can reconstruct the original data from any k packets without needing retransmission. This eliminates the time-consuming retransmission process while maintaining reliability.
Solution Approach 2:
The patent changes the fundamental parameter of error recovery from active retransmission to passive redundancy. By encoding k original packets into n encoded packets (n>k), the system transforms the recovery mechanism from time-dependent retransmission to space-dependent redundancy, eliminating delay increases.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
This application provides a method and a device for transmitting data streams. In the method, the data streams are transmitted between a source node and a destination node by using an intermediate node; the data streams include a first data stream whose encoded form is fountain code; and the method includes: receiving, by a first intermediate node, an encoded packet sent by the source node or at least one second intermediate node, where the encoded packet is a packet obtained after an original packet of the first data stream is encoded by using a fountain code technology; and dropping, by the first intermediate node, the encoded packet when usage of a first cache queue exceeds a threshold, where the first cache queue is a cache queue allocated to the first data stream by the first intermediate node, and the threshold indicates maximum allowed usage of the first cache queue. Therefore, in the present invention, on a premise that no closed-loop control loop needs to be used, reliable transmission of a data stream can be ensured, network congestion can be reduced, and implementation complexity can be reduced compared with the prior art.