Downlink DTMF Signal Shielding in Radio Networks
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Solution Overview
Problem
In radio communication networks, downlink Dual Tone Multi-Frequency (DTMF) signals can be maliciously used, posing safety hazards, and existing solutions either compromise network quality or fail to effectively prevent such misuse.
Innovation Solution
A method and device for processing downlink signals in a radio communication network that detect and shield DTMF signals by modifying or discarding DTMF frames in the PCM code stream, preventing them from being recognized by called terminals without affecting network quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If radio interference is implemented to eliminate malicious downlink DTMF signals, then safety hazards are eliminated, but network quality deteriorates
Solution Approach 1:
The patent extracts and removes only the harmful DTMF signal components from the downlink PCM stream while preserving the legitimate voice communication content. The system detects DTMF frames using frequency domain analysis and selectively discards only those frames containing malicious DTMF signals, rather than blocking all downlink traffic, thus maintaining network quality while eliminating safety hazards.
Solution Approach 2:
The patent changes the parameter of signal processing by introducing frequency domain analysis to detect DTMF signals within the PCM stream. By monitoring frequency characteristics (detecting row and column frequencies corresponding to DTMF tones), the system can identify and remove only the harmful signals without affecting the overall network quality and communication reliability.
2Object-affected harmful factors
If downlink DTMF signals are blocked entirely, then malicious use is prevented, but legitimate DTMF signaling is also prevented
Solution Approach 1:
The patent applies local quality by treating different parts of the downlink signal differently. Instead of blocking all downlink DTMF signals uniformly, the system selectively processes only those frames that contain detected DTMF patterns, while allowing other legitimate signal frames to pass through unchanged. This selective approach prevents malicious use while preserving legitimate DTMF signaling functionality where appropriate.
Solution Approach 2:
The patent implements feedback through continuous monitoring of the downlink PCM stream for DTMF signal patterns. The system detects DTMF frames, determines whether they should be blocked based on the harmful use criteria, and adjusts the processing accordingly. This feedback mechanism ensures that legitimate DTMF signaling is not unnecessarily blocked while preventing malicious usage.
Data Source
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AI summary
The present invention provides a method, device, and system for processing a downlink signal. A method for processing a downlink signal includes: receiving a downlink signal; detecting whether a dual tone multi-frequency (DTMF) signal exists in the downlink signal; and when a DTMF signals exists in the downlink signal, performing shielding processing on the DTMF signal in the downlink signal. With the method for processing a downlink signal provided in the embodiments of the present invention, the downlink DTMF signaling in the downlink message and the downlink DTMF frame in the downlink PCM frame can be detected, and the downlink DTMF signaling and the downlink DTMF frame can be shielded, so as to prevent the malicious use of the downlink DTMF signal.