Dynamic Timer Management for Unlicensed Spectrum Data Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE systems using unlicensed spectra, user equipment (UE) often experiences increased probability of failing to receive responses before timers expire due to base stations' continuous spectrum occupation assumptions, leading to resource wastage and inefficient data transmission.
Innovation Solution
Implementing a data transmission method where UE starts a timer during a current channel occupation duration (COD), pauses it at the end of the COD, determines the end of a long pilot region in the next COD, resumes the timer, and receives a response message before it expires, effectively stopping time counting during the base station's listen before talk (LBT) process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base station continuously occupies the spectrum in LTE systems, then the UE timer operation can proceed normally, but when using unlicensed spectrum with LBT process, the timer expires before receiving response messages due to random LBT delays
Solution Approach 1:
The patent makes the timer dynamic by allowing it to be paused and resumed based on the base station's COD status. The timer is paused when the base station ends its current COD and performs LBT, and resumed when the base station starts a new COD. This dynamic adjustment ensures the timer reflects the actual time available for response message reception, preventing premature expiration during LBT periods.
Solution Approach 2:
The patent implements feedback mechanisms where the UE monitors the base station's COD status through pilot signals and short pilots. The UE receives feedback about when the base station ends its current COD and performs LBT, allowing the UE to adjust its timer accordingly. This feedback loop ensures the timer operation is synchronized with the base station's actual transmission status.
2Adaptability or versatility
If the base station performs LBT process on unlicensed spectrum, then spectrum sharing is enabled, but the UE cannot determine when to resume timer and receive response messages
Solution Approach 1:
The patent uses preliminary actions by having the base station send pilot signals and short pilots before actual data transmission. These preliminary signals allow the UE to detect the base station's COD status in advance and prepare for timer pausing or resuming. The UE determines the end moment of current COD and the end moment of LP region in next COD based on these preliminary signals, enabling proactive timer management.
Solution Approach 2:
The patent introduces pilot signals and short pilots as intermediaries between the base station and UE for timing synchronization. These intermediary signals carry information about the base station's COD status, allowing the UE to indirectly determine when to pause or resume the timer without directly monitoring the base station's internal state. This intermediary mechanism simplifies the UE's timer management complexity.
3Ease of operation
If the UE uses fixed timer duration, then timer operation is simple, but response messages may be lost during LBT periods causing retransmissions
Solution Approach 1:
The patent transforms the fixed timer into a dynamic timer that adapts to the base station's COD status. The timer is paused during LBT periods and resumed when the base station becomes active again. This dynamic behavior maintains operational simplicity from the UE's perspective while significantly improving data transmission efficiency by preventing response message loss during LBT periods.
Data Source
AI summary
Embodiments of the present application provide a data transmission method, and the method is used for communication between UE and a base station on an unlicensed spectrum. The method includes: sending, by the UE, a data packet to the base station and starting a timer during a current COD of the base station; determining a first end moment of the current COD; pausing the timer at the first end moment; determining a second end moment of an LP in a next COD of the base station; resuming the timer at the second end moment; and receiving, before the resumed timer expires, a response message from the base station. In the embodiments of the present application, the UE suspends the timer at the end moment of the previous COD and resumes the timer at the end moment of the LP of the next COD.