MAC PDU Length Encoding for Extended Header Decoding
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Solution Overview
Problem
The 14-bit length field in MAC PDUs is not contiguous, making processing complex and affecting wireless communication system efficiency, especially for high data rate connections where the length information exceeds the encoding capacity of the EH length field.
Innovation Solution
A method and system for encoding and decoding MAC PDUs that include a first field indicating the presence of extended headers and a second field indicating the length of the extended header group, allowing for efficient transmission and reception without needing to parse the extended headers to determine the length, using a combination of fields in the MAC header and extended header group to convey length information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the 14-bit length field is split into two parts (11 bits in GMH and 3 bits in LEH), then the encoding capacity is increased to accommodate large MAC PDUs, but the processing complexity increases and receiver performance deteriorates
Solution Approach 1:
The 14-bit length field is segmented into two parts: an 11-bit length field in the GMH and a 3-bit extension length field in the LEH. This segmentation allows the system to accommodate MAC PDU lengths up to 16383 bytes while maintaining backward compatibility with existing standards
Solution Approach 2:
The EH field acts as an intermediary indicator that triggers the inclusion of the LEH. When the EH field is set to a specific value, it signals the receiver that a LEH is present and contains additional length information, simplifying the receiver's decision-making process
2Adaptability or versatility
If the EH group field carries variable size EHs, then the adaptability is improved, but the encoding capacity of the EH length field is exceeded for high data rate connections
Solution Approach 1:
The solution adds another dimension to the length encoding by introducing the LEH that is conditionally included based on the EH field value. This allows the system to extend the encoding capacity beyond the original 8-bit EH length field limitation without changing the basic variable-size EH structure
3Measurement precision
If the receiver must parse the EH group field to decode the LEH, then the length information can be accurately determined, but the processing time increases and system efficiency decreases
Solution Approach 1:
The GMH length field provides preliminary length information that allows the receiver to quickly determine the basic MAC PDU length without parsing the EH group. The 3-bit extension in the LEH only needs to be processed when the EH field indicates its presence, reducing the average processing time
Data Source
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AI summary
Methods and apparatuses are provided for transmitting and receiving a MAC PDU. The MAC PDU including a MAC header, an extended header group and a payload is generated. The MAC PDU is transmitted to a receiving device. The extended header group includes a first field that indicates whether at least one extended header is included in the extended header group, and a second field that indicates a length of the extended header group.