H-ARQ Process Assignment for Priority-Based E-DCH Retransmission
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently managing uplink transmissions, particularly in assigning and prioritizing data blocks for automatic repeat request (ARQ) and hybrid automatic repeat request (H-ARQ) processes to enhance uplink coverage, throughput, and reduce latency, as the Radio Network Controller (RNC) has limited capability to manage short-term radio resources effectively.
Innovation Solution
A method and apparatus for assigning H-ARQ processes in a wireless transmit/receive unit (WTRU) that configures parameters for enhanced uplink operations, prioritizes data transmission based on medium access control (MAC) flow, and manages retransmissions by allocating available H-ARQ processes, incrementing transmission counts, and discarding data when the maximum number of retransmissions is reached.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the RNC manages uplink radio resources, then overall cell control and congestion control are maintained, but short-term radio resource management efficiency deteriorates
Solution Approach 1:
The patent segments the resource management functions by creating a separate MAC-e entity in the WTRU that handles short-term uplink resource management (transmission power control, resource allocation) independently from the RNC's overall cell control. This segmentation allows the WTRU to autonomously manage its uplink transmissions while the RNC maintains macro-level control, resolving the contradiction between short-term efficiency and architectural complexity.
2Adaptability or versatility
If multiple independent uplink transmissions are processed within a common time interval, then transmission flexibility increases, but proper assignment of data blocks to ARQ/H-ARQ processes becomes more complex
Solution Approach 1:
The patent applies preliminary action by pre-configuring multiple ARQ/H-ARQ processes with specific parameters (priority levels, maximum retransmission counts, data block sizes) before transmission occurs. The MAC-e entity in the WTRU uses these pre-configured processes to immediately assign incoming data blocks to appropriate ARQ processes based on priority and resource availability, eliminating the need for complex real-time assignment decisions and enabling flexible multi-transmission processing.
3Reliability
If data prioritization based on MAC-d flow priority is implemented, then quality of service is improved, but transmission scheduling complexity increases
Solution Approach 1:
The patent implements local quality by assigning different priority levels and QoS parameters to different MAC-d flows and their corresponding ARQ processes. Each ARQ process is configured with specific priority characteristics matching the data flow it serves, allowing the MAC-e entity to make simple local scheduling decisions (assign highest priority available data to available ARQ processes) rather than complex global optimization, thus achieving QoS differentiation with minimal scheduling complexity.
Data Source
AI summary
A method and apparatus for assigning a hybrid-automatic repeat request (H-ARQ) process in a wireless transmit/receive unit (WTRU) to support enhanced uplink (EU) data transmission. Configuration parameters for enhanced uplink (EU) operation are received. The configuration parameters include a priority associated with a medium access control for dedicated channel (MAC-d) flow and a maximum number of H-ARQ transmissions associated with the MAC-d flow. Data is selected for transmission over an enhanced dedicated channel (E-DCH) based on a priority of the MAC-d flow, wherein data with the highest priority is selected. On a condition that the selected data is new data that was not previously transmitted, an available H-ARQ process is assigned for supporting transmission of the selected data, and the selected data is transmitted over the E-DCH using the assigned H-ARQ process. On a condition that the selected data was previously transmitted, the selected data is retransmitted over the E-DCH using the same H-ARQ process that was assigned to previously transmit the selected data. A transmission count is incremented in response to transmitting or retransmitting the selected data. A determination is made of whether the transmission count is at least equal to the maximum number of H-ARQ transmissions. The selected data is discarded in response to a determination that the transmission count is at least equal to the maximum number of H-ARQ transmissions.