Control Channel Transmission for Seamless LTE Handover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE systems, communication interruptions occur during UE handover due to undetected control signaling by the base station, particularly when reconfiguring enhanced physical downlink control channels (ePDCCH) between serving cells.
Innovation Solution
Configuring both cell-specific and user equipment-specific enhanced physical downlink control channels (ePDCCHs) and using these channels to send control information during handover, ensuring continuous communication by reconfiguring control channels without interruption, such as by using a user equipment-specific control channel to send information about control when reconfiguring a cell-specific control channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base station sends RRC reconfiguration signaling to reconfigure ePDCCH during cell handover, then the ePDCCH configuration is updated for the target cell, but control signaling is not detected by the UE during the reconfiguration period causing communication interruption
Solution Approach 1:
The base station sends indication information in advance before the UE completes ePDCCH reconfiguration, notifying the UE to switch to cell-specific control channel for downlink control information. This preliminary action ensures that control signaling can be maintained during the reconfiguration transition period, preventing communication interruption.
Solution Approach 2:
The patent introduces an intermediary mechanism where the base station uses indication information (RRC signaling or physical downlink control information) to mediate the transition between UE-specific ePDCCH and cell-specific control channel. This intermediary ensures seamless handover by coordinating the switch between different control channel configurations.
2Adaptability or versatility
If the UE reconfigures ePDCCH from first serving cell to second serving cell, then the control channel is adapted to the new cell, but control signaling detection fails during the reconfiguration process
Solution Approach 1:
The patent implements a dynamic control channel configuration where the UE can switch between UE-specific ePDCCH and cell-specific control channel based on handover status. The base station dynamically adjusts the control channel configuration by sending indication information, allowing the system to adapt to different operational states while maintaining reliable control signaling detection.
Solution Approach 2:
The UE is configured to monitor both UE-specific ePDCCH and cell-specific control channel, making the control channel system multi-functional. This universality ensures that control signaling can be detected regardless of which cell the UE is currently serving, maintaining reliability during handover transitions.
3Productivity
If only UE-specific ePDCCH is configured for handover, then the control channel is optimized for the specific UE, but alternative control channel for fallback is not available causing communication interruption
Solution Approach 1:
The patent changes the control channel configuration parameters dynamically based on handover conditions. The base station configures both UE-specific ePDCCH parameters and cell-specific control channel parameters, and switches between them by changing the active configuration state through indication information. This parameter change approach maintains both efficiency and reliability.
Solution Approach 2:
The base station pre-configures the cell-specific control channel as a fallback option before handover occurs. This beforehand cushioning ensures that if UE-specific ePDCCH detection fails during handover, the UE can immediately switch to the pre-prepared cell-specific control channel, preventing communication interruption.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The embodiments of the present invention provide a control channel transmission method and a piece of equipment, where the method includes: configuring, by a communications system, at least two control channels for a user equipment, where at least one of the control channels is a cell-specific control channel and at least one of the control channels is a user equipment-specific control channel; using, by the communications system, the cell-specific control channel and/or user equipment-specific control channel to send information about control over the user equipment. In the embodiments of the present invention, a communications system configures at least two control channels for a UE. The communications system may use, in a process of reconfiguring a control channel, another control channel to send information about control over the UE to ensure that communication is not interrupted during cell handover of the UE.