Multicast Feedback Timing Advance for Idle UE Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communications systems, UEs in inactive or idle mode often lack a valid timing advance (TA) for transmitting feedback on multicast messages, leading to increased latency, resource wastage, and inefficient network use due to the need to transition to connected mode for TA acquisition.
Innovation Solution
A base station configures UEs in inactive or idle mode with resources and timing advance information, allowing them to transmit feedback without entering connected mode, using random access channel (RACH) or physical uplink control channel (PUCCH) resources, and optionally provides probabilistic indicators for feedback transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If UEs in inactive or idle mode transition to connected mode to obtain valid TA before transmitting feedback, then feedback transmission can be performed with proper timing, but latency increases and UE resources (power, battery life) are wasted
Solution Approach 1:
The base station performs preliminary actions by providing timing advance (TA) commands to UEs in inactive or idle mode before feedback transmission is needed. This allows UEs to have valid TA information ready when they need to transmit feedback, eliminating the need to transition to connected mode solely for TA acquisition, thus reducing latency while maintaining reliability
2Reliability
If UEs in inactive or idle mode transition to connected mode to obtain valid TA, then proper timing for feedback can be achieved, but UE power consumption increases and battery life decreases
Solution Approach 1:
The base station provides TA commands to UEs in inactive or idle mode in advance, so UEs have valid timing information stored when needed. This preliminary provision of TA information eliminates the energy-intensive transition to connected mode, allowing UEs to transmit feedback directly from their current low-power state, thus reducing power consumption while maintaining transmission reliability
3Loss of energy
If UEs in inactive or idle mode refrain from transmitting feedback due to lacking valid TA, then network resources are protected from misaligned transmissions, but network efficiency decreases due to inability to perform multicast retransmissions
Solution Approach 1:
The system implements a feedback mechanism where UEs in inactive or idle mode can transmit feedback (ACK/NACK) for multicast transmissions. The base station provides necessary TA information to enable this feedback transmission, allowing the network to receive reliability information about multicast delivery and perform efficient retransmissions when needed, thus improving network productivity while maintaining resource efficiency through proper feedback-based retransmission control
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Methods, systems, and devices for multicast wireless communications are described. A base station may configure a user equipment (UE) for providing feedback for multicast transmissions from the base station while the UE is in an inactive or idle mode. Based on a configuration sent to the UE from the base station, the UE may determine resources or a timing advance (TA) to use for transmission of a feedback message for multicast communications. A base station may configure a UE with multiple TA commands, each corresponding to a TA value and a set of channel metrics associated with group of cells including a serving cell of the UE. Based on measure channel metrics at the UE, the UE may determine a TA to use for multicast feedback. TA values may be determined using neural network modeling.