Flexible RLC PDU Byte-Count Window Management
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Solution Overview
Problem
Existing RLC protocols in HSPA+ systems face inefficiencies with flexible PDU sizes, leading to potential buffer overflows and underflows due to fixed PDU size-based window management, which is not suitable for variable PDU operations.
Innovation Solution
Implementing byte-count based methods for RNC/Node-B flow control, RLC flow control, and status reporting to manage window sizes efficiently, allowing for flexible RLC PDU sizes by using metrics like number of bytes, blocks, or sequence numbers, and signaling these during RRC setup to ensure accurate window configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If fixed PDU size-based window management is used, then RLC operations are simple to manage, but buffer overflows and underflows occur with flexible PDU sizes
Solution Approach 1:
The patent changes the fundamental parameter used for window management from fixed PDU size to variable byte-count based sizing. This allows the window management mechanism to adapt to flexible PDU sizes by using byte-based metrics (such as byte-based sequence numbers and window size indicators) instead of assuming fixed PDU sizes, thereby preventing buffer overflows and underflows while maintaining operational simplicity.
2Measurement precision
If byte-count based methods are implemented for flow control, then buffer management accuracy improves, but system complexity increases
Solution Approach 1:
The patent introduces dynamic byte-count based window management where window sizes and sequence numbers are adjusted based on actual PDU sizes. The system dynamically calculates window boundaries and manages buffer allocations based on variable PDU lengths, enabling accurate buffer management for flexible sizes. This dynamic approach replaces static fixed-size assumptions with adaptive byte-based control.
Solution Approach 2:
The patent transitions from one-dimensional PDU count-based management to two-dimensional management by introducing byte-count as an additional dimension. This allows simultaneous tracking of both PDU sequence numbers and byte offsets, enabling precise buffer management. The byte-based sequence numbers and window size indicators provide an extra layer of granularity for managing flexible PDU sizes.
3Productivity
If flexible RLC PDU sizes are supported, then data transfer efficiency improves, but existing RLC protocols become incompatible
Solution Approach 1:
The patent creates a universal byte-count based window management mechanism that can handle both fixed and flexible PDU sizes. By using byte-based sequence numbers and window size indicators, the system becomes multi-functional, supporting variable PDU sizes while maintaining compatibility with existing RLC protocol structures. The byte-based approach serves as a universal framework that subsumes both fixed and flexible size scenarios.
Data Source
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AI summary
A method for polling and an associated transmitting entity configured to support flexible packet data unit size are disclosed. A byte count mechanism is maintained, wherein the byte count mechanism maintains a count associated with a number of bytes transmitted. It is determined that the count is equal to or exceeds a Poll_Bytes value, and a packet data unit is configured to include a poll.