Resetting MAC Entity During LTE RRC Connection Cell Reselection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the LTE wireless communication system, cell reselection during an ongoing RRC Connection procedure leads to incomplete and erroneous RRC Connection procedures due to the failure to reset the MAC layer and re-establish RLC layer mapping, resulting in redundant message transmissions and incorrect Random Access procedures.
Innovation Solution
The method involves resetting or re-establishing the lower layer protocol entity for a Signaling Radio Bearer (SRB) when cell reselection occurs, including re-establishing the Transparent Mode (TM) RLC entity and resetting the Medium Access Control (MAC) entity, and flushing the transmission buffer to discard un-transmitted Service Data Units (SDUs).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cell reselection occurs during ongoing RRC Connection procedure without resetting lower layer protocol entities, then the system maintains continuity of existing protocol entities, but the Random Access procedure cannot be correctly performed and redundant Connection Request messages are transmitted
Solution Approach 1:
The patent applies preliminary action by detecting cell reselection during the RRC Connection procedure and proactively resetting the MAC entity and re-establishing RLC entities before transmitting the Connection Request message. This prevents the harmful effect of sending redundant messages to the wrong cell by preparing the protocol entities in advance to match the new cell context.
2Reliability
If the MAC layer is not reset during cell reselection, then the system maintains existing MAC state and reduces signaling overhead, but the Random Access procedure for the new cell cannot be correctly performed
Solution Approach 1:
The MAC entity is reset preliminarily upon detecting cell reselection during RRC Connection procedure, ensuring that the Random Access procedure will be performed correctly for the new cell. This preliminary reset prevents subsequent procedure errors and message retransmissions, ultimately reducing total time loss despite the initial reset overhead.
3Reliability
If RLC layer mapping is not re-established during cell reselection, then transmission buffers are maintained and data transmission continuity is preserved, but Connection Request messages may be redundantly transmitted to incorrect cells
Solution Approach 1:
The RLC entities mapped to SRBs are re-established preliminarily when cell reselection is detected during RRC Connection procedure. This ensures that Connection Request messages are correctly associated with the new cell's radio bearer configuration, preventing redundant transmissions to the old cell and reducing unnecessary data loss.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for improving a Radio Resource Control (RRC) Connection procedure in a user equipment (UE) of a wireless communication system is disclosed. The method includes steps of performing an RRC Connection procedure (402), and resetting a Medium Access Control entity for Signaling Radio Bearers (SRBs) when a cell reselection occurs (404), wherein the Medium Access Control Entity handles a Random Access procedure.