Sequence Number Expansion in Wireless Frame Headers
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Solution Overview
Problem
Current IEEE 802.11 standards have a limited 12-bit sequence number space, which is insufficient for supporting higher throughput wireless communications, leading to challenges in efficiently managing retransmissions of data packets due to imperfect channel conditions.
Innovation Solution
The method involves expanding the sequence number space by embedding a unique sequence number greater than 12 bits in the control field and sequence number field of the frame header, using techniques such as adding bits to the MPDU delimiter, repurposing bits in the CCMP or GCMP headers, and incorporating sequence number extensions in the HE control field, allowing for a larger sequence number space without altering existing MPDU configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the sequence number space is expanded to support higher throughput wireless communications, then the capacity to manage retransmissions is improved, but the complexity of the frame header structure increases
Solution Approach 1:
The sequence number is divided into two parts: the original 12-bit sequence number field in the MAC header and an additional sequence number extension field. This segmentation allows the sequence number space to be expanded from 4096 to 16384 values while maintaining the original frame structure for legacy compatibility and adding only the necessary extension bits for enhanced throughput support.
Solution Approach 2:
The sequence number extension is nested within the existing frame header structure by utilizing available bits in the MAC header. The patent embeds the extended sequence number information within the existing frame format, specifically using the A-Control field or other header fields, thereby expanding functionality without requiring a completely new frame structure.
2Quantity of substance
If bits are added to the MPDU delimiter or headers to expand sequence number space, then the sequence number capacity is improved, but the modification complexity of existing MPDU formats increases
Solution Approach 1:
The patent makes existing header fields multi-functional by using them to carry both original control information and extended sequence number information. For example, the A-Control field is used to carry additional sequence number bits, allowing the same field to serve dual purposes: maintaining legacy control functionality while enabling expanded sequence number capacity.
Solution Approach 2:
The patent changes the parameter configuration of existing fields by repurposing certain bits in the MAC header to carry sequence number extension information. This parameter change allows the sequence number space to be expanded from 12 bits to 16 bits without fundamentally altering the MPDU format, thereby reducing modification complexity.
3Productivity
If the sequence number field is expanded beyond 12 bits, then the support for higher throughput is improved, but the compatibility with legacy devices may be affected
Solution Approach 1:
The patent implements a dynamic approach where the sequence number extension is conditionally applied. Legacy devices that do not support the extension can process frames using the original 12-bit sequence number, while newer devices capable of handling the expanded format can utilize the full 16-bit sequence number space. This dynamic compatibility ensures backward compatibility while enabling enhanced throughput support.
Solution Approach 2:
The patent uses the A-Control field or other header fields as an intermediary to carry the extended sequence number information. This intermediary approach allows the extended sequence number to be transmitted without directly modifying the core sequence number field that legacy devices rely on, thereby maintaining compatibility while enabling extended functionality.
Data Source
AI summary
This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for identifying frames or packets of data that were received in error (such as incorrectly decoded or not received at all) by a receiving device for purposes of retransmission. In one aspect, a wireless device may form a number of frames for wireless transmission. Each of the frames may include a frame header and may be associated with a unique sequence number. In some implementations, for each of the frames, the wireless device may embed at least a portion of the unique sequence number into a portion of a control field or a delimiter field of the frame header. In some other implementations, for each of the frames, the wireless device may signal at least a portion of the unique sequence number using bit locations unassociated with a sequence number field of the frame header.