DTMF Signaling Reliability via Unique Tone Sequences
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
DTMF signaling between mobile devices and servers is unreliable and inefficient, particularly when the data channel is unavailable, leading to challenges in reliable communication and user experience due to errors and slow communication speeds.
Innovation Solution
A method is implemented where messages are encoded with unique DTMF tone sequences that can be identified even if only a subset of tones are received, and error correction mechanisms are used to ensure message integrity, including re-sending important messages and utilizing 'acknowledge' and 'negative acknowledgement' messages to manage transmission errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DTMF signaling is used over the voice channel when the data channel is unavailable, then communication can continue, but reliability and transmission speed deteriorate due to errors and inefficiency
Solution Approach 1:
The system performs preliminary actions by encoding messages with unique DTMF tone sequences that contain built-in error detection capabilities before transmission. The server prepares acknowledge and negative acknowledgement message templates in advance, enabling rapid error handling without complex real-time processing when transmission errors occur over the voice channel.
Solution Approach 2:
The system implements feedback mechanisms where the mobile device sends acknowledge messages upon successful message reception and negative acknowledgement messages when errors occur. The server receives these feedback signals and automatically re-sends important messages if negative acknowledgements are received, creating a closed-loop communication system that continuously monitors and corrects transmission errors.
2Reliability
If error correction mechanisms and re-transmission protocols are implemented, then message delivery reliability improves, but system complexity increases
Solution Approach 1:
The system extracts and separates the error handling functionality into distinct acknowledge and negative acknowledgement message types. By isolating error detection and correction logic into specific message protocols rather than embedding complex error correction algorithms throughout the entire communication stack, the system achieves reliable message delivery while maintaining relative simplicity in the overall architecture.
Solution Approach 2:
The system uses simple, easily generated DTMF tone sequences with basic unique identification patterns rather than complex error correction codes. These lightweight signaling elements can be quickly generated and processed, providing sufficient error detection capability without requiring sophisticated algorithms or extensive computational resources, thus keeping the system simple while maintaining reliability.
3Measurement precision
If unique DTMF tone sequences with error detection capabilities are used, then error detection ability improves, but the number of tones required increases
Solution Approach 1:
The system applies partial error detection by using unique DTMF tone sequences that provide sufficient discrimination between different messages without implementing complete and exhaustive error correction. The unique tone sequences contain just enough information to detect transmission errors and identify messages, balancing error detection capability with efficient use of signaling resources and minimizing the number of tones required.
Data Source
Figure 1A
Figure 1B
Figure 2~4
AI summary
A method of communicating, at a mobile communications device server (14), with a mobile communications device (11) served by the server is provided. The method comprises upon receipt of an indicator indicating receipt by the mobile communications device (11) of an unrecognized message, determining if a first message was sent to the mobile communications device (11) in a previous pre-determined window of time; and re-sending the first message if the determining determines that the first message was sent to the mobile communications device (11) in the previous pre-determined window of time.