Primary Component Carrier Change via RACH Procedure
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Solution Overview
Problem
In wireless communication systems, particularly in LTE-A, there is no clear method to determine which component carriers can perform the random access channel (RACH) procedure, making it difficult to change the primary component carrier without completing the RACH procedure, which is essential for maintaining connectivity during handovers.
Innovation Solution
A method and device that allow a user equipment (UE) to receive a handover command to change its primary component carrier by performing a RACH procedure on specified or indicated uplink or downlink component carriers, enabling successful handover by identifying suitable carriers for the RACH process based on provided information or predetermined strategies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the UE performs handover procedure without clear RACH procedure specification, then handover speed is improved, but connection reliability deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-configuring RACH parameters and procedures in the handover command message before the actual handover execution. The network provides RACH configuration information for target component carriers in advance, enabling the UE to immediately perform RACH procedure without additional signaling delays, thus improving handover speed while ensuring connection reliability through pre-validated RACH parameters
2Adaptability or versatility
If the system allows flexible PCC change, then network flexibility is improved, but procedure complexity increases
Solution Approach 1:
The patent applies segmentation by separating the PCC change procedure into distinct phases: RACH procedure phase and PCC activation phase. The handover command includes separate RACH configuration for target carriers and separate PCC change indication. This segmentation allows flexible PCC change while reducing procedure complexity by providing clear, step-by-step execution steps for the UE
Solution Approach 2:
The patent uses the handover command message as an intermediary that carries both RACH configuration information and PCC change instructions. This intermediary mechanism consolidates multiple control functions into a single standardized message structure, enabling flexible PCC change without increasing overall procedure complexity
3Reliability
If the RACH procedure is required on all component carriers, then connection reliability is improved, but handover time increases
Solution Approach 1:
The patent applies partial action by requiring RACH procedure only on the target component carrier where the UE needs to establish uplink synchronization, rather than on all component carriers. The handover command specifies RACH configuration only for the relevant target carrier, allowing the UE to complete handover faster while maintaining connection reliability through targeted RACH execution
Data Source
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AI summary
A method of changing a primary component carrier (PCC) for a mobile device in a wireless communication system is disclosed. The method comprises receiving a handover command from a network of the wireless communication system to change a first uplink primary component carrier of a first plurality of uplink component carriers or a first downlink primary component carrier of a first plurality of downlink component carriers, and performing a random access channel (RACH) procedure on at least one of uplink component carriers according to the handover command.