UE Contention Resolution Timer Adaptation for NTN Power
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Solution Overview
Problem
In wireless communication systems, particularly in Non-Terrestrial Networks (NTNs), the existing contention resolution mechanisms for Random Access (RA) procedures face challenges due to longer round trip times and increased power consumption, as the current timer settings are not adequately long to account for the larger round trip delays, leading to potential failures in contention resolution and inefficient resource management.
Innovation Solution
The User Equipment (UE) employs a dual-timer approach for contention resolution, starting a first timer with a specific value after Msg3 transmission and restarting it with a potentially longer value after Msg3 retransmission, along with a timing offset to account for the longer round trip times in NTNs, allowing for more flexible scheduling and reduced power consumption by optimizing PDCCH monitoring periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contention resolution timer is extended to account for longer round trip times in NTNs, then the reliability of contention resolution is improved, but the power consumption increases due to extended PDCCH monitoring periods
Solution Approach 1:
The patent applies dynamics by making the timer value adaptive rather than fixed. The UE determines the contention resolution timer value based on whether it is operating in NTN or TN mode, allowing the system to dynamically adjust the timer duration to match the actual round trip time characteristics of the network environment, thereby avoiding unnecessarily long monitoring periods in TN while ensuring sufficient time in NTN.
Solution Approach 2:
The patent changes the parameter of timer duration based on network type. By setting different timer values for NTN and TN operations, the system optimizes the balance between reliability and power consumption. In NTN, a longer timer accounts for extended round trip times, while in TN, a shorter timer reduces power consumption, directly addressing the technical contradiction.
2Reliability
If the contention resolution timer is extended for NTN operations, then the reliability of contention resolution is improved, but the time efficiency deteriorates due to longer waiting periods
Solution Approach 1:
The patent changes the timer parameter based on network type to optimize the balance between reliability and time efficiency. By setting appropriate timer values for NTN and TN scenarios, the system ensures sufficient time for contention resolution in NTN while avoiding unnecessary delays in TN, thus resolving the contradiction between reliability and time loss.
3Reliability
If the UE monitors PDCCH continuously to ensure reliable contention resolution, then the reliability is improved, but the power consumption increases
Solution Approach 1:
The patent applies dynamics by adjusting the PDCCH monitoring duration based on network type. The UE monitors PDCCH for the duration of the contention resolution timer, which is dynamically set based on whether the UE is in NTN or TN mode. This dynamic adjustment ensures reliable contention resolution monitoring when needed while reducing power consumption during normal TN operations.
Data Source
AI summary
Methods and apparatuses for a User Equipment (UE) to monitor the Physical Downlink Control Channel (PDCCH) appropriately in order to reduce power consumption and perform Contention Resolution for a Random Access (RA) procedure in a Non-Terrestrial Network (NTN). The UE can perform a Msg3 transmission during a RA procedure in a NTN and start a RA contention resolution timer in the first symbol after the end of the Msg3 transmission plus a timing offset. In response to expiry of the RA contention resolution timer, the UE determines whether to consider Contention Resolution not successful based on at least whether the RA contention resolution timer expires during a time duration of the timing offset after a Msg3 retransmission.