VoIP Spam Detection via Audio Analysis During Ringing

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Solution Overview

Problem

VoIP systems face challenges in detecting and counteracting spam calls, known as SPIT, which utilize the Session Initiation Protocol to deliver unsolicited messages, as traditional spam filters are ineffective in this context due to the nature of VoIP communications over IP networks.

Innovation Solution

A method is implemented to detect spam calls by analyzing audio data received during a voice communication session, identifying potential spam sources through the presence of audible messages during a ringing tone, and managing sessions accordingly, with the option to add spam sources to a blacklist for future blocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional spam filters are used in VoIP systems, then email and instant messaging spam can be blocked, but SPIT (spam over internet telephony) cannot be detected or counteracted

Engineering Contradiction:
Improvespam filtering effectivenessVSAvoidapplicability to different spam types
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces an audio analysis intermediary that sits between the VoIP call establishment and the user. This intermediary captures and analyzes the audio stream during the call, specifically looking for characteristics of spam messages. The intermediary translates audio data into analyzable formats and applies detection algorithms, effectively bridging the gap between traditional spam filtering and VoIP-specific requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional text-based spam filtering mechanisms with audio-based detection mechanisms. Instead of analyzing text content, the system analyzes audio waveforms, frequency spectra, and temporal patterns of voice communications. This substitution enables the system to detect SPIT by examining acoustic characteristics of spam calls rather than relying on text-based filtering rules.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If audio analysis is performed during every voice communication session to detect spam, then SPIT can be detected, but system complexity and processing overhead increase

Engineering Contradiction:
Improvespam detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary audio analysis during the ringing phase of a VoIP call, before the actual communication begins. By analyzing audio characteristics during this preliminary period, the system can identify spam callers early in the call establishment process. This preliminary action allows the system to terminate spam calls before they consume significant resources or reach the user, reducing overall system complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies partial audio analysis by focusing only on specific time windows and frequency ranges that are most indicative of spam messages. Rather than analyzing the entire audio spectrum throughout the entire call duration, the system concentrates computational resources on critical detection periods and frequencies, reducing processing overhead while maintaining detection accuracy.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If spam calls are terminated immediately upon detection, then unwanted communications are reduced, but legitimate calls may be incorrectly blocked

Engineering Contradiction:
Improvecall filtering efficiencyVSAvoidcall legitimacy verification
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where detected spam characteristics are recorded and used to refine detection algorithms. The system learns from confirmed spam patterns and adjusts its detection criteria accordingly. This feedback loop allows the system to improve its accuracy over time, reducing false positives while maintaining high spam detection rates. User feedback on misclassified calls further refines the system's ability to distinguish legitimate from spam calls.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS8953471B2Counteracting spam in voice over internet protocol telephony systems
Publication Date: 2015.02.10 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US8953471B2 patent drawing
  • US8953471B2 patent drawing
  • US8953471B2 patent drawing

AI summary

An approach is provided to detect a spam message transmitted over a packetized, network-based telephony system. A request to initiate a first voice communication session is received from a requestor. A voice communications session is established with the requestor over the computer network. An audible ringing tone is sent to the requestor over the established voice communications session. While the audible ringing tone is being sent, audio data that is received from the requestor is analyzed. If the analysis detects an audible message in the audio data, then the requestor is identified as a possible spam source. On the other hand, if the analysis fails to detect the audible message in the audio data then the established voice communications session is handled as a non-spam event.