Wireless Receiver BlockAck Timeout Detection and NormalAck Switching
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Solution Overview
Problem
The IEEE 802.11e standard lacks specifications for the order of data frame transmission during a NormalAck scheme switch from BlockAck scheme, leading to issues with unreceived data frames being considered valid for extended periods, causing delays in passing subsequent data frames to the upper layer and resource allocation problems due to undetected BlockAck scheme terminations.
Innovation Solution
Implementing rules to ensure data frames with Sequence Numbers less than x are retransmitted before x in the NormalAck scheme during BlockAck scheme communications, and detecting BlockAck Timeout by not receiving a data frame or BlockAckReq frame within a predetermined period to release resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the BlockAck scheme is used to send acknowledgements for multiple frames together in one frame, then bandwidth efficiency is improved, but transmission delay increases
Solution Approach 1:
The patent dynamically switches between BlockAck scheme and NormalAck scheme based on buffer status and transmission conditions. The receiving station adaptively selects which acknowledgment mode to use, allowing the system to optimize between bandwidth efficiency and transmission delay depending on current network conditions and buffer states.
2Ease of operation
If the NormalAck scheme is switched from BlockAck scheme without proper sequencing rules, then individual frame acknowledgements are improved, but data frame transmission order and validity detection deteriorate
Solution Approach 1:
The patent establishes preliminary rules for sequence number management before NormalAck switching occurs. The receiving station pre-defines the relationship between sequence numbers in BlockAck and NormalAck modes, ensuring that when switching schemes, the transmission order and validity of data frames are maintained through pre-established sequencing conventions.
Solution Approach 2:
The patent implements feedback mechanisms where the receiving station monitors sequence numbers and provides acknowledgment information that helps the transmitting station understand which frames have been received and in what order. This feedback loop ensures reliable transmission order maintenance even when switching between acknowledgment schemes.
3Duration of action of stationary object
If BlockAck Timeout detection is not implemented, then resource allocation continues without interruption, but resource release and efficiency deteriorate
Solution Approach 1:
The patent implements periodic timeout detection mechanisms where the receiving station regularly checks whether BlockAck acknowledgments are being received within expected time intervals. This periodic monitoring allows the system to maintain resource allocation during normal operation while automatically detecting when resources should be released due to timeout conditions, balancing continuity with efficiency.
Data Source
AI summary
A receiver capable of switching between a NormalAck scheme that includes an acknowledgement for a single frame in one frame and a BlockAck scheme that includes an acknowledgement for a plurality of frames in one frame. The receiver regards the use of the BlockAck scheme to have been terminated and releases resource being used for the BlockAck scheme and switches to the NormalAck scheme if a data frame requesting the BlockAck scheme is not received within a predetermined period regardless of whether the receiving station has or has not received a data frame requesting the NormalAck scheme.