D2D Resource Determination via RRC State Indicator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, particularly in public safety networks, there is a need for device-to-device (D2D) operation methods that allow terminals to perform D2D signal transmission using preconfigured resources, but existing systems lack clarity on the Radio Resource Control (RRC) state in which these resources are applicable, leading to uncertainty and potential interference in cellular coverage.
Innovation Solution
A method where a user equipment (UE) receives an indicator from system information to determine whether and how to use preconfigured D2D resources within cell coverage, specifically identifying the RRC state for resource application, allowing for clear D2D signal transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a terminal uses preconfigured D2D resources autonomously in cell coverage, then D2D transmission reliability is improved, but resource conflict and interference with cellular communication increases
Solution Approach 1:
The patent applies dynamics by making the D2D resource usage flexible and state-dependent. The terminal dynamically adjusts its resource selection based on RRC state transitions and network configuration. When in RRC connected state, the terminal follows network-scheduled resources; when transitioning to idle state, it can autonomously use preconfigured resources if permitted. This dynamic adaptation resolves the contradiction by allowing reliable D2D transmission only when network conditions permit, thereby avoiding resource conflicts.
Solution Approach 2:
The patent changes the parameter of resource allocation mode based on RRC state. The system transitions between two resource allocation parameters: network-scheduled mode (when connected) and autonomous preconfigured mode (when idle, if permitted). This parameter change is controlled by the indicator received from system information and RRC state transitions, enabling the terminal to switch between conflicting resource usage modes appropriately.
2Adaptability or versatility
If system information provides only mode-2 transmission resources without RRC state indication, then resource pool flexibility is improved, but terminal uncertainty about resource applicability increases
Solution Approach 1:
The patent introduces an intermediary indicator in system information that mediates between the network's resource configuration and the terminal's resource selection. This indicator explicitly specifies whether preconfigured D2D resources can be used in RRC idle state, eliminating terminal uncertainty while preserving resource pool flexibility. The indicator acts as a clear directive from network to terminal, resolving the information asymmetry problem.
3Object-affected harmful factors
If the network controls D2D resource usage through scheduling, then resource conflict is reduced, but D2D transmission delay increases
Solution Approach 1:
The patent segments D2D resource usage into two distinct modes: network-scheduled mode for connected state and autonomous preconfigured mode for idle state (when permitted). This segmentation allows the system to reduce resource conflict through network control when necessary, while enabling low-delay autonomous transmission when the terminal is idle and network scheduling is unavailable. The segmentation resolves the contradiction by applying different control strategies to different operational contexts.
Data Source
AI summary
Provided is a D2D operation method performed by a terminal in a wireless communication system, and a terminal using same. In the method, received is indication information indicating whether or not using preconfigured D2D resources within cell coverage is permitted, resources for D2D signal transmission are determined on the basis of the indication information, and a D2D signal is transmitted by using the determined resources.