Dynamic Soft Buffer Allocation for HARQ Processes

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Solution Overview

Problem

The Next Generation Mobile Network (NGMN) requires larger soft buffer sizes in user equipment (UE) for hybrid automatic repeat request (HARQ) processes due to wider channel bandwidths, leading to increased costs and potential buffer insufficiency, especially with carrier aggregation and multi-subframe scheduling.

Innovation Solution

Implementing a method where UE dynamically reports data processing capabilities, including soft buffer size and signal processing delay, to enable efficient scheduling of HARQ data, allowing for the reuse of soft buffers and increased buffer utilization by releasing buffers when data is decoded successfully, thereby supporting more HARQ processes with reduced buffer size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If wider channel bandwidth is used in NR systems, then transmission speed and bandwidth requirements are met, but soft buffer size requirement increases significantly

Engineering Contradiction:
Improvetransmission speedVSAvoidsoft buffer size
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The patent implements dynamic soft buffer allocation where the buffer size for each HARQ process is adjusted based on the actual transport block size of scheduled transmissions. Instead of allocating fixed maximum buffer size to each HARQ process, the buffer size dynamically adapts to the actual data volume, allowing efficient utilization of limited buffer resources while supporting wide bandwidth transmissions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the buffer size parameter dynamically based on scheduling decisions and transport block sizes. The network device determines the soft buffer size for each HARQ process according to the scheduled transport block size, and the UE configures its soft buffer accordingly. This parameter adaptation allows the system to support variable bandwidth requirements without requiring maximum buffer size for all processes simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If more HARQ processes are supported, then scheduling flexibility and throughput are improved, but soft buffer memory requirement increases

Engineering Contradiction:
Improvescheduling flexibilityVSAvoidsoft buffer memory
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent makes soft buffers universal by allowing the same physical buffer memory to serve multiple HARQ processes at different times. The soft buffer is not permanently assigned to a specific HARQ process but is allocated dynamically based on scheduling needs. This multi-functional use of buffer resources allows the system to support more HARQ processes than the number of physical buffers available.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically reallocates soft buffer resources among HARQ processes based on current scheduling requirements. When a HARQ process is scheduled for transmission, the corresponding soft buffer size is activated; when not scheduled, the buffer resources are effectively released for potential reuse by other processes. This dynamic resource sharing enables high scheduling flexibility with limited buffer memory.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If fixed soft buffer size is allocated to each HARQ process, then buffer management is simplified, but buffer utilization efficiency decreases

Engineering Contradiction:
Improvebuffer managementVSAvoidbuffer utilization efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent changes the buffer size parameter from a fixed value to a dynamically determined value based on the transport block size of scheduled transmissions. The network device calculates the required soft buffer size for each HARQ process according to the actual data volume, and this information is signaled to the UE for buffer configuration. This approach maintains operational simplicity through automated calculation while dramatically improving utilization efficiency.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If larger soft buffer is provided in UE, then more HARQ processes can be handled, but UE cost increases

Engineering Contradiction:
ImproveHARQ process capacityVSAvoidUE cost
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system implements dynamic soft buffer sizing where the UE only allocates buffer memory for HARQ processes that are currently scheduled for transmission. Instead of provisioning buffer memory for all possible HARQ processes simultaneously, the UE dynamically activates buffer resources based on actual scheduling needs. This reduces the peak buffer memory requirement and associated cost while maintaining the capability to handle multiple HARQ processes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The UE adapts its soft buffer size parameter based on network scheduling decisions and capability indications. The network device determines appropriate buffer sizes and signals them to the UE, which then configures its buffer resources accordingly. This parameter adaptation allows the UE to operate with smaller, more cost-effective buffer memory while still supporting the required HARQ process capacity through time-multiplexed buffer usage.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3326314B1Method for hybrid automatic repeat request process, network device and terminal device
Publication Date: 2020.01.08 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3326314B1 patent drawingFigure 1~2
  • EP3326314B1 patent drawingFigure 3a~3b
  • EP3326314B1 patent drawingFigure 4~5

AI summary

The present disclosure provides a method in a network device for hybrid automatic repeat request (HARQ) processes; the method comprising receiving from a terminal device one or more data processing capacity indications indicating one or more data processing capabilities of the terminal device; estimating the number of available soft buffers in the terminal device; and scheduling hybrid automatic repeat request (HARQ) data according to the estimated number.