G-MPDU Encapsulation and Fragmentation for Wireless Data Transmission
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Solution Overview
Problem
Current data transmission methods, such as MPDU aggregation and fragmentation in 802.11 and 802.16 systems, face inefficiencies in resource utilization and data transmission speed, particularly when dealing with long MPDU sizes or poor channel conditions, leading to increased re-transmissions and signaling overhead.
Innovation Solution
The method involves encapsulating one or multiple MPDU as a G-MPDU, fragmenting MPDU when residual length is insufficient, and setting fragmentation indication information to indicate fragmentation, allowing for efficient transmission and reassembly of non-fragmented MPDU at the receiving end.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If MPDU aggregation is used to transmit data, then data transmission efficiency is improved, but when MPDU is too long or channel condition is bad, transmission failure occurs requiring re-transmission
Solution Approach 1:
The patent segments the long MPDU into multiple smaller MPDUs and transmits them as separate A-MPDU units. Each segmented MPDU has its own delimiter and length field, allowing independent transmission and reception. This resolves the contradiction by maintaining aggregation efficiency while avoiding the risks of transmitting overly long single MPDUs.
2Reliability
If fragmentation is used to transmit MPDU, then transmission reliability is improved by avoiding oversize data, but fragmentation processing consumes system resources and reduces data transmission rate
Solution Approach 1:
The patent merges multiple fragmented MPDUs into a single A-MPDU unit for transmission, while maintaining the ability to independently process each fragment. The A-MPDU structure allows multiple MPDUs to be aggregated with delimiters, combining the benefits of fragmentation (avoiding oversize issues) with aggregation (improving transmission efficiency and reducing processing overhead).
Solution Approach 2:
The patent dynamically adjusts the fragmentation strategy by evaluating residual length after each MPDU encapsulation. When residual length is insufficient for another complete MPDU, fragmentation is applied only when beneficial (when residual exceeds minimum fragmentation length). This dynamic approach optimizes the balance between reliability and transmission rate based on actual data conditions.
3Quantity of substance
If fragmentation is applied to utilize residual length, then resource utilization is improved, but fragmentation processing time increases
Solution Approach 1:
The patent applies partial fragmentation action by setting a minimum fragmentation length threshold. Fragmentation is performed only when the residual length exceeds this threshold, avoiding unnecessary fragmentation processing for small residual segments. This partial action approach maintains good resource utilization while minimizing processing time overhead.
4Productivity
If A-MPDU aggregation is used with integral MPDU, then transmission efficiency is high, but when channel condition is bad, the entire A-MPDU may fail requiring re-transmission of all data
Solution Approach 1:
The patent segments the A-MPDU into multiple independent MPDU units, each with its own delimiter and length field. When transmission errors occur, only the affected MPDUs need to be re-transmitted rather than the entire A-MPDU. This segmentation provides error resilience while maintaining the aggregation efficiency benefits.
Data Source
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AI summary
A method and apparatus for transmitting and receiving data are disclosed. The method for transmitting data, comprising encapsulating one or multiple media access control protocol data units (MPDU) as a group media access control protocol data unit (G-MPDU) based on a length of the group media access control protocol data unit G-MPDU; fragmenting a current MPDU according to a residual length to obtain a fragmented MPDU when the residual length is insufficient to encapsulate the current MPDU; encapsulating the fragmented MPDU to the G-MPDU; and transmitting the encapsulated G-MPDU. The method ensures a high data transmission rate and does not wasting excess time to execute the fragmentation processing. The method also ensures a high resource utilization rate, utilizing fully the remaining length of the data unit.