NFC Collision Resolution for SDD-Unsupported Devices
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Solution Overview
Problem
Existing NFC collision resolution mechanisms fail to effectively handle multiple NFC-A devices, particularly when one or more devices do not support Single Device Detection (SDD), leading to inefficiencies in communication and collision resolution processes.
Innovation Solution
A communications device or apparatus equipped with a collision resolution module that determines which remote NFC devices support SDD, resolves those that do, and identifies those that do not, using a flag or RID message to manage unresolved devices, thereby improving collision resolution efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the collision resolution logical loop continuously sends NFC-A SDD commands to all detected devices, then the collision resolution process follows the standard specification, but devices that do not support SDD cannot be properly resolved leading to communication failures
Solution Approach 1:
The patent inverts the traditional approach by first attempting to resolve devices using SDD commands, then detecting which devices remain unresolved, and finally sending RID commands to those specific unresolved devices. This inversion allows the system to adapt to both SDD-supported and SDD-unsupported devices without requiring prior knowledge of device capabilities.
Solution Approach 2:
The patent implements a feedback mechanism where the system monitors the responses to SDD commands to determine which devices support SDD and which do not. Based on this feedback, the system dynamically adjusts its collision resolution strategy by sending RID commands only to devices that did not respond to SDD commands, thereby achieving universal compatibility.
2Adaptability or versatility
If the system sends RID messages to all unresolved devices, then compatibility with SDD-unsupported devices is improved, but unnecessary messages are sent to devices that already support SDD reducing efficiency
Solution Approach 1:
The patent extracts and identifies the subset of devices that did not respond to SDD commands by analyzing the collision resolution loop responses. Instead of sending RID commands to all devices, the system selectively sends RID commands only to the extracted subset of unresolved devices, thereby improving efficiency while maintaining compatibility.
Solution Approach 2:
The patent applies partial action by sending RID commands only to the necessary subset of devices that require it, rather than sending commands to all devices. This partial approach optimizes the collision resolution process by avoiding unnecessary communications with devices that already support SDD.
3Measurement precision
If the collision resolution loop is executed multiple times to differentiate each device, then device identification accuracy is improved, but the time required for collision resolution increases
Solution Approach 1:
The patent introduces dynamic adaptability into the collision resolution process by adjusting the communication strategy based on device responses. The system dynamically switches between SDD commands for resolved devices and RID commands for unresolved devices, allowing for accurate device identification while reducing the overall time required compared to executing the full logical loop multiple times for all devices.
Data Source
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AI summary
Aspects disclosed herein relate to providing an improved collision resolution mechanism for handling multiple NFC-A devices where one or more of the NFC-A devices may not support SDD. In one example, a communications device is equipped to determine that a remote NFC device of two or more remote NFC devices supports SDD, resolve the remote NFC device of the two or more remote NFC devices using SDD, and determine whether a remaining remote NFC device of the two or more remote NFC devices supports SDD. In an aspect in which the remaining remote NFC device does not support SDD, the communications device may be equipped to set a flag indicating that unresolved remote NFC devices are present and/or send a read identifier (RID) message to the remaining remote NFC device.