Network Topology Determination via Echo Channel Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In co-frequency full duplex network systems, determining the network topology is complex due to the impact of external interference and the complexity of fault locating, especially when uplink and downlink signals are transmitted at the same frequency, making it difficult to obtain connection relationships between network elements.
Innovation Solution
A method that uses echo cancellation modules and Fast Fourier Transform (FFT) to convert frequency domain characteristics of echo channels into time domain characteristics, allowing for the determination of trunk cable lengths, drop cable lengths, and correspondence between cable modems and splitters/taps based on SINR, thereby simplifying the determination of network topology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If co-frequency full duplex technology is used to transmit uplink and downlink signals at the same frequency, then spectrum efficiency is doubled, but external interference impact increases and fault locating becomes complex
Solution Approach 1:
The patent segments the network topology determination process into distinct steps: obtaining frequency domain characteristics of echo channels, converting to time domain characteristics via FFT, determining cable lengths from time domain peaks, and establishing CM-splitters/taps correspondence through SINR analysis. This segmentation transforms a complex undifferentiated problem into manageable discrete tasks.
Solution Approach 2:
The patent introduces time domain characteristics (impulse response or TDR) as an intermediary between the frequency domain echo channel characteristics and the final topology determination. This intermediary representation makes the hidden cable length and connection information visible and measurable through peak detection.
2Productivity
If co-frequency full duplex technology is used to transmit uplink and downlink signals at the same frequency, then spectrum efficiency is doubled, but fault locating complexity increases
Solution Approach 1:
The patent introduces time domain characteristics (impulse response or TDR) as an intermediary between the frequency domain echo channel characteristics and the final topology determination. This intermediary representation makes the hidden cable length and connection information visible and measurable through peak detection.
Solution Approach 2:
The patent replaces complex physical fault locating operations with signal processing operations. Instead of manually tracing cables and testing connections, the system uses FFT transformation and peak detection algorithms to automatically determine cable lengths and topology, substituting mechanical/physical measurement methods with computational methods.
3Reliability
If network topology determination is performed in FDX system to enable monitoring and fault locating, then network management capability is improved, but system complexity increases
Solution Approach 1:
The patent enables the network system to automatically determine its own topology using existing echo cancellation modules and signal processing capabilities already present in the FDX system. The system uses its own operational signals (echo channels) to generate topology information without requiring separate dedicated measurement equipment or external intervention.
Solution Approach 2:
The patent makes the echo cancellation modules serve multiple functions: their primary function of eliminating echo interference is maintained, and additionally they provide frequency domain characteristics that are transformed into topology information. This multi-functionality avoids adding separate dedicated topology measurement devices.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach efficiently and simply determines network topology, enhances fault locating, and improves network monitoring and maintenance by analyzing echo severity and sending prompt alarms for severe echo points, reducing the complexity of fault identification.
Implementation Method 1
convert the frequency domain characteristic of the echo channel of the CMTS to the first time domain characteristic of the echo channel of the CMTS through fast Fourier transform (FFT)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Embodiments of this application provide a network topology determining method, apparatus, and system. The method includes: determining a length of a trunk cable based on a first time domain characteristic of an echo channel of a cable modem termination system CMTS; determining, based on a second time domain characteristic of an echo channel of each cable modem CM, a length of a drop cable connected to the trunk cable; determining a connection relationship between each CM and the trunk cable based on a signal to interference plus noise ratio SINR between any two of the CMs; and determining a topology of a network based on the length of the trunk cable, the length of the drop cable, and the connection relationship between each CM and the trunk cable. According to the embodiments of this application, the topology of the network can be simply and quickly determined.