Semi-Persistent Grant Collision Resolution via Priority Selection

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Solution Overview

Problem

In V2x communications, multiple semi-persistent grants can cause collisions at terminal devices, leading to inefficient use of network resources, as existing technologies lack effective methods to handle these collisions, particularly in device-to-device (D2D) sidelink and cellular uplink scenarios.

Innovation Solution

A method where wireless devices and network nodes use predefined selection criteria, such as index, size of radio resource grants, and priority, to select one semi-persistent configuration when multiple configurations grant the same radio resource, ensuring efficient transmission and reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple semi-persistent grants are allocated to a terminal device, then the device can support multiple services or traffic types simultaneously, but resource collisions occur when multiple configurations grant the same radio resource

Engineering Contradiction:
Improvemulti-service supportVSAvoidresource collision
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the selection criteria parameters (priority values, resource indices, grant sizes) to resolve collisions. When multiple semi-persistent configurations collide on the same radio resource, the terminal device compares parameters such as priority levels assigned to each configuration and selects the configuration with the highest priority, thereby resolving the collision while maintaining multi-service support capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of preventing collisions from occurring in the first place through complex resource allocation, the patent inverts the approach by allowing collisions to occur and then resolving them through a standardized selection process. The terminal device and network node both apply the same selection criteria (comparing priority parameters, resource indices) to independently determine which configuration should use the contested resource, ensuring consistent resolution without requiring complex coordination

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If selection criteria are used to resolve collisions, then resource allocation is simplified, but processing overhead increases due to comparison operations

Engineering Contradiction:
Improveresource allocationVSAvoidprocessing overhead
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring priority values and selection criteria parameters before collisions occur. The network node assigns priority levels to different semi-persistent configurations in advance, and the terminal device stores these parameters for quick comparison. When a collision occurs, the device simply compares the pre-configured parameters rather than performing complex real-time analysis, reducing processing overhead while maintaining ease of operation

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3510818B1Systems and methods of handling collisions between multiple semi-persistent grants
Publication Date: 2021.04.21 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3510818B1 patent drawingFigure 1
  • EP3510818B1 patent drawingFigure 2
  • EP3510818B1 patent drawingFigure 3

AI summary

Systems and methods of handling collisions between multiple semi-persistent grants are presented herein. In one exemplary embodiment, a method performed by a wireless device (211, 311, 400, 500a-b, 700, 800a-b, 1000, 1411, 2200) in a wireless communications system (200, 300, 1400) comprises obtaining (607) selection criteria (207, 307, 1407) that is predefined or configured as being the criteria by which both the wireless device and a network node (201, 301, 1100, 1200a-b, 1401, 1500, 1600a-b, 2100) or another wireless device (313, 1413) selects one of multiple activated semi-persistent configurations (233, 243, 333, 343, 1433, 1443) assigned to the wireless device responsive to determining that the multiple configurations have granted a same radio resource (247, 347, 1447). Further, the method includes selecting (609) one of the multiple configurations based on the selection criteria. Also, the method includes transmitting or receiving (611) on that radio resource in accordance with the selected configuration.