Radio Terminal DRX Timing Adjustment via Control Channel
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Solution Overview
Problem
The lengthening of the extended DRX cycle in mobile communication systems leads to a prolonged Off duration, causing synchronization shifts in uplink signals due to delayed reception of transmission timing correction information, which can exceed the maximum reception interval.
Innovation Solution
A mobile communication method that includes transmitting a timing adjustment request uplink signal from the radio terminal to the base station, even when an uplink data channel resource is not assigned, to receive transmission timing correction information, and determining the maximum reception interval based on the terminal's movement speed to prevent synchronization shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If an extended DRX cycle is configured to reduce network resource consumption, then power saving and network resource efficiency are improved, but the Off duration becomes very long causing synchronization shifts in uplink signals
Solution Approach 1:
The radio terminal transmits a timing adjustment request uplink signal in advance during the On duration before the Off duration begins. This preliminary action ensures that the base station can provide transmission timing correction information (TA) before the long Off duration starts, preventing synchronization shifts that would otherwise occur during the extended idle period.
Solution Approach 2:
The extended DRX cycle is segmented into distinct phases: an On duration for active communication and signal exchange, and a long Off duration for power saving. By segmenting the cycle and handling timing adjustment specifically during the On duration, the system maintains synchronization reliability while achieving power savings during the Off duration.
2Productivity
If the radio terminal receives TA only in On duration, then network resource usage is reduced, but the interval for receiving TA may exceed the maximum TA reception interval causing synchronization shifts
Solution Approach 1:
The terminal sends a timing adjustment request during the On duration as a preliminary action, ensuring that TA is received before the long Off duration begins. This allows the system to maintain synchronization reliability while keeping the terminal in a low-power state during the Off duration, thus preserving network resource efficiency.
3Reliability
If a timing adjustment request is transmitted through uplink control channel without uplink data channel resource assignment, then synchronization accuracy is maintained, but additional signaling overhead is introduced
Solution Approach 1:
The terminal autonomously transmits a timing adjustment request uplink signal on the uplink control channel when needed, without requiring base station scheduling or uplink data channel resources. This self-service approach maintains synchronization accuracy while minimizing signaling overhead by using existing control channel resources efficiently.
Data Source
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AI summary
A mobile communication method, which configures a DRX cycle having an On duration in which a downlink signal transmitted from a serving base station is to be monitored and an Off duration other than the On duration in an RRC connected state where an RRC connection is established between a UE 10 and an eNB 110, the mobile communication method comprising: a step A of transmitting, from the UE 10 to the eNB 110, a timing adjustment request uplink signal through an uplink control channel, even when a radio resource of an uplink data channel has not been assigned in a case where the DRX cycle is configured.