HARQ Process Management for Dynamic Uplink Downlink Configuration Changes
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Solution Overview
Problem
In wireless communication systems, dynamic changes in radio resource configurations can lead to inefficiencies in HARQ processes, resulting in average packet throughput loss and packet delay due to the inability to continuously use existing HARQ processes.
Innovation Solution
A method is introduced where predetermined information about HARQ processes is received from a lower layer to change the uplink/downlink configuration, allowing for the termination or retransmission of HARQ processes that cannot be linked to the new configuration, using a specific timer value and flushing service data units from buffers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ processes are maintained during uplink/downlink configuration changes, then packet throughput is preserved, but packet delay increases due to inability to terminate outdated processes
Solution Approach 1:
The patent applies preliminary action by flushing service data units from HARQ buffers before configuration changes take effect. The network device determines which HARQ processes are affected by the upcoming configuration change and proactively clears their buffers, preventing packet delay while maintaining throughput by ensuring clean state transition.
Solution Approach 2:
The patent uses parameter changes by modifying the HARQ process state parameters (buffer status, process validity) in response to configuration changes. The network device changes the operational parameters of HARQ processes based on the new uplink/downlink configuration, enabling efficient resource reallocation without compromising packet throughput.
2Loss of time
If HARQ processes are rapidly terminated during configuration changes, then packet delay is reduced, but packet throughput is lost due to interrupted retransmissions
Solution Approach 1:
The patent applies local quality by selectively flushing only the service data units associated with HARQ processes that are affected by the configuration change, rather than terminating all HARQ processes. This localized approach maintains throughput for unaffected processes while reducing delay for affected ones.
Solution Approach 2:
The network device performs preliminary identification of which HARQ processes need to be flushed before the configuration change takes effect, allowing for targeted buffer clearing that minimizes throughput impact while achieving delay reduction.
3Productivity
If dynamic resource allocation is implemented, then radio resource efficiency is improved, but HARQ process management complexity increases
Solution Approach 1:
The patent uses feedback by having the network device monitor and determine which HARQ processes are affected by configuration changes, then automatically flushing the appropriate buffers. This feedback mechanism simplifies management complexity by providing automated decision-making based on configuration state.
Solution Approach 2:
The system applies self-service by automatically identifying and flushing HARQ buffers that need to be cleared during configuration changes, without requiring complex external management. The network device itself manages the HARQ process state transitions based on the configuration change detection.
Data Source
AI summary
The present application discloses a method for executing a hybrid automatic repeat and request (HARQ) process from a particular layer at a receiving end in a wireless communication system. Specifically, the method comprises the steps of: receiving predetermined information regarding one or more HARQ processes from a subordinate layer so as to change a configuration of a previously configured first uplink/downlink subframe configuration to a configuration of a second uplink/downlink subframe configuration; and processing one or more HARQ processes on the basis of the predetermined information when changing to the second uplink/downlink subframe configuration, wherein the one or more HARQ processes are HARQ processes, from among the HARQ processes linked to the first uplink/downlink subframe configuration, which cannot be linked to the second uplink/downlink subframe configuration.