Adaptive Locality Check Timeline for Wireless Content Protection
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Solution Overview
Problem
High-bandwidth Digital Content Protection (HDCP) locality checks fail in wireless networks due to unpredictable random access delays, leading to long setup delays in wireless local area networks like Wi-Fi, where multiple users access the same communication medium, making it difficult to enforce the required Round Trip Time (RTT) of 7 milliseconds for content protection.
Innovation Solution
A method and system that dynamically adjust the locality check timeline by accounting for processing delays and wireless channel access delays, allowing a locality check response to be marked as valid if it arrives after the original time period but before an adjusted timeframe, ensuring successful content protection key exchange in wireless communication systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed locality check time period is used in wireless networks, then content protection can be enforced, but random access delays cause locality check failures and long setup delays
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed locality check time period to a dynamic, adaptive time period. The transmitter adjusts the locality check time period based on measured round-trip times and estimated random access delays, allowing the system to adapt to varying wireless network conditions. This resolves the contradiction by making the time parameter flexible rather than rigid, enabling successful locality checks despite random access delays while maintaining security requirements.
Solution Approach 2:
The patent changes the parameter of locality check time period from a constant value to a variable that is adjusted based on network conditions. Specifically, the transmitter modifies the time period parameter by adding estimated random access delays to the base round-trip time, allowing the system to accommodate variable wireless access delays while maintaining content protection integrity.
2Reliability
If the locality check time period is extended to account for random access delays, then locality check success rate improves, but content protection security may be compromised
Solution Approach 1:
The patent implements feedback by continuously measuring the actual round-trip time for locality check messages and using this information to adjust the locality check time period. The transmitter receives feedback from the receiver's response messages and adapts the time period accordingly, ensuring that the extended time period is only as long as necessary to accommodate actual network conditions, not arbitrary extensions that would compromise security.
Solution Approach 2:
The patent applies preliminary action by estimating random access delays before conducting the locality check and pre-adjusting the time period accordingly. This allows the system to proactively account for expected delays without waiting for failures to occur, ensuring both success rate and security by setting an appropriate time period in advance based on measured network characteristics.
Data Source
AI summary
A method and system for data communication in a wireless network is provided. A wireless transmitter transmits a locality check message from a wireless transmitter to a wireless receiver over a wireless communication medium. Upon receiving a locality check response message from the wireless receiver, the wireless transmitter marks the locality check response message as valid even if it arrives after an original locality check time period since transmission of the locality check message, but before the end of an adjusted locality check time period. The adjusted locality check time period comprises said original locality check time period adjusted by delays in processing layers at the transmitter and wireless communication medium access delays in data communication between the wireless transmitter and the wireless receiver.