Distributed Unit Cell Activation via Central Unit Context Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, particularly in multi-hop networks, there is a challenge in efficiently managing energy saving modes in distributed units (DUs), leading to excessive network overhead and inappropriate actions when cells are deactivated or in energy saving mode, affecting service availability and network control.
Innovation Solution
The implementation of a method where a distributed unit (DU) can initiate cell activation or deactivation by transmitting configuration updates to a central unit (CU), allowing the CU to store cell contexts during energy saving modes, and providing rejection messages with specific causes for service requests, enabling appropriate network control actions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a DU deactivates a cell for energy saving, then energy consumption is reduced, but network overhead increases due to excessive cell context deletion and reactivation signaling
Solution Approach 1:
The CU is preemptively configured with cell context information before the DU actually needs to reactivate the cell. When the CU receives an RRC setup request for a cell that is currently deactivated, it can immediately provide the stored cell context to the DU, eliminating the need for the DU to delete and re-establish the context during reactivation. This preliminary configuration approach reduces the signaling overhead associated with cell reactivation while maintaining energy-saving benefits during cell deactivation periods.
2Use of energy by moving object
If a DU operates in energy saving mode, then energy resource usage is optimized, but service availability deteriorates due to inability to fulfill UE context setup requests
Solution Approach 1:
The CU acts as an intermediary that maintains cell context information even when the DU is in energy-saving mode with cells deactivated. When a UE context setup request arrives at the CU for a deactivated cell, the CU retrieves the stored cell context and forwards it to the DU, enabling the DU to quickly activate the cell and fulfill the service request without prolonged service unavailability. This intermediary approach allows the DU to remain in energy-saving mode while maintaining service availability through CU intervention.
3Device complexity
If a CU rejects service requests when DU is in energy saving mode, then network control is simplified, but inappropriate actions occur due to inability to differentiate energy saving rejections from congestion rejections
Solution Approach 1:
The system implements feedback mechanisms where the DU explicitly indicates to the CU when it is operating in energy-saving mode and cannot fulfill certain requests. This feedback allows the CU to differentiate between rejections due to energy-saving mode versus rejections due to congestion or other issues. Based on this feedback, the CU can take appropriate actions such as providing stored cell context for deactivated cells or selecting alternative DUs, thereby maintaining adaptability in service management while simplifying network control through clear status indication.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a distributed unit may transmit, to a central unit of the distributed unit, a configuration update including a request to change an activation status of a cell of the distributed unit. The distributed unit may receive, from the central unit, a configuration update acknowledgement based at least in part on transmitting the configuration update including the request to change the activation status of the cell of the distributed unit. Numerous other aspects are provided.