LMR Adapter Using Mobile Phone Headset for Hands-Free PTT
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Solution Overview
Problem
Conventional land mobile radio equipment requires continuous hand use for transmit operations, is bulky, and expensive, and receive operations necessitate costly and intrusive speaker installation, which can cause operator distraction and increase costs.
Innovation Solution
A portable land mobile radio transceiver system that uses a standard mobile phone headset adapter to convert the 'answer/end' switch into a push-to-talk signal, allowing for hands-free operation and compatibility with vehicle audio systems, eliminating the need for dedicated speakers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional push-to-talk microphone and external speaker accessories are used, then transmit operation can be performed, but continuous hand use is required causing operator distraction
Solution Approach 1:
The patent introduces an intermediary device (adapter) that connects the LMR transceiver to a standard mobile phone headset. This adapter captures audio from the headset's microphone and converts the headset's answer/end switch actuation into PTT signals, enabling hands-free operation without requiring the operator to manually depress a microphone switch while driving.
Solution Approach 2:
The patent makes the LMR transceiver compatible with standard mobile phone headsets, which are universally used devices. By adapting to the headset's existing answer/end switch mechanism rather than requiring a dedicated PTT switch, the system achieves multi-functionality and ease of operation using familiar interfaces.
2Device complexity
If conventional microphone systems are used, then transmit operation can be performed, but the equipment is relatively bulky and expensive
Solution Approach 1:
The patent extracts the microphone functionality from a separate bulky conventional microphone system and integrates it into the existing mobile phone headset. This eliminates the need for dedicated radio microphone hardware, reducing equipment size and cost while maintaining transmit operation capability.
Solution Approach 2:
The patent uses the existing answer/end switch mechanism from the mobile phone headset as a functional copy or substitute for the traditional PTT switch. This approach avoids manufacturing and installing expensive dedicated PTT hardware while achieving the same transmit control function.
3Ease of operation
If dedicated radio speaker installation is performed, then receive operation can be performed, but costly and intrusive installation is required
Solution Approach 1:
The patent makes the LMR transceiver compatible with standard mobile phone headsets, which are universally used devices. By adapting to the headset's existing answer/end switch mechanism rather than requiring a dedicated PTT switch, the system achieves multi-functionality and ease of operation using familiar interfaces.
Solution Approach 2:
The patent introduces an intermediary device (adapter) that connects the LMR transceiver to a standard mobile phone headset. This adapter captures audio from the headset's microphone and converts the headset's answer/end switch actuation into PTT signals, enabling hands-free operation without requiring the operator to manually depress a microphone switch while driving.
Data Source
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AI summary
An adapter (400) for a portable land mobile radio (LMR) transceiver system (414) where the LMR includes a push-to-talk (PTT) transmitter control system. The adapter includes a tip-ring-sleeve (TRS) type interface connector (402) configured to accept a plug (101) from a standard mobile phone headset. An adapter circuit (401) is configured to detect a momentary actuation of an answer/end switch (201) of a standard mobile phone headset when a TRS plug of the standard mobile phone headset is inserted in the interface connector (402). The adapter circuit alternately latches a PTT input of the LMR transmitter control system in either a transmit active state, or a transmit inactive state, in response to actuation of the answer/end switch of the mobile phone handset.