Wireless Display Back Channel for Bidirectional User Input
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Solution Overview
Problem
Current wireless display systems lack efficient methods for bidirectional communication between wireless source and sink devices, particularly in transmitting user inputs from sink devices back to source devices, which limits user control and seamless content management across devices.
Innovation Solution
A system where a wireless sink device generates and transmits data packets with user input data to a wireless source device, including a data packet header identifying the user input data, allowing for bidirectional communication and control of content transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless display systems use unidirectional communication from source to sink device, then the system structure is simple, but user control capability is limited
Solution Approach 1:
The patent implements a feedback mechanism by establishing a back channel that allows the sink device to send user input data back to the source device. This enables bidirectional communication where the sink device can forward user inputs (such as remote control signals, keyboard inputs, or touch screen gestures) to the source device, allowing users to control the content playback on the source device through the sink device's interface.
2Adaptability or versatility
If wireless display systems implement bidirectional communication for user control, then user control capability is enhanced, but data transmission complexity increases
Solution Approach 1:
The sink device acts as an intermediary between the user and the source device. It receives various types of user inputs from external devices (remote controls, keyboards, touch screens), processes and formats them into standardized data packets, and forwards them to the source device. This intermediary role simplifies the overall system architecture by consolidating the control functionality at the sink device while maintaining versatility in supporting multiple input device types.
Solution Approach 2:
The sink device is designed with multi-functionality, serving both as a display/output device and as a control input device. It can receive and process multiple types of user inputs from different external devices, format them uniformly, and transmit control commands to the source device, thereby providing universal control capability across different input device types without requiring separate control mechanisms for each device.
3Productivity
If user input data is transmitted from sink to source device, then seamless interaction is achieved, but communication protocol complexity increases
Solution Approach 1:
The patent extracts the control signal transmission function from the existing wireless display protocol and implements it as a separate back channel. This allows user input data to be transmitted independently from the audio/video data stream, using a simplified protocol specifically designed for control commands. The extraction of this functionality reduces the complexity of the overall communication protocol by separating control and media data transmission paths.
Data Source
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AI summary
As part of a communication session, a wireless source device can transmit audio and video data to a wireless sink device, and the wireless sink device can transmit user input data received at the wireless sink device back to the wireless source device. In an aspect, this includes receiving, by the wireless source device, a data packet from the wireless sink device, the data packet comprising a data packet header and payload data, parsing, by the wireless source device, the data packet header for a four-bit input category field and a timestamp flag that indicates whether the data packet header includes a sixteen-bit timestamp field, in response to the timestamp flag indicating that the data packet header does include the timestamp field, parsing, by the wireless source device, the data packet header to identify, based on a representation of a timestamp included in the timestamp field, a particular frame of video data that was displayed by the wireless sink device while user input data was captured and processing, by the wireless source device, the payload data based at least in part on the identified particular frame of the video data.