Signaling Timing Advance Offsets in IAB Networks
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Solution Overview
Problem
Current wireless communication technologies face challenges in efficiently managing timing advance (TA) offsets in integrated access and backhaul (IAB) networks, particularly in 5G New Radio (NR) networks, where downlink and uplink timing alignment is not always synchronized, leading to misalignment issues that existing TA command specifications cannot adequately address.
Innovation Solution
The introduction of additional TA signaling methods, such as new fields in MAC RAR and MAC CE messages, to indicate both the initial TA value and the timing misalignment (NTA,Δ) value, allowing child IAB nodes and UEs to properly align their transmit timing with the parent node, even when downlink and uplink timings are not aligned.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing TA command specifications are used in IAB networks, then device complexity is reduced, but timing alignment precision deteriorates due to inability to address downlink and uplink timing misalignment
Solution Approach 1:
The patent segments the timing advance parameter into two distinct components: the initial TA value (NTA) and the timing misalignment value (NTA,Δ). This segmentation allows each parameter to be signaled and processed independently, enabling precise timing alignment while maintaining clear protocol structure. The child IAB node receives and processes these separate values to calculate the adjusted TA for uplink transmission.
Solution Approach 2:
The patent introduces the timing misalignment value (NTA,Δ) as an intermediary parameter that mediates between the downlink timing reference and the uplink transmission timing. This intermediary allows the system to account for the timing difference introduced by IAB network architecture, enabling accurate timing alignment without requiring complete redesign of the TA signaling mechanism.
2Adaptability or versatility
If downlink and uplink timing are synchronized in IAB networks, then timing alignment is simplified, but adaptability to real-world timing differences deteriorates
Solution Approach 1:
The patent applies preliminary action by having the parent IAB node calculate and signal both the initial TA value and the timing misalignment value to the child IAB node before uplink transmission occurs. This advance provision of timing parameters allows the child node to pre-calculate the appropriate uplink transmission timing, simplifying the actual transmission process while adapting to timing differences.
Solution Approach 2:
The patent changes the timing parameters dynamically by introducing the timing misalignment value (NTA,Δ) that can be adjusted based on actual downlink and uplink timing differences. This parameter change mechanism allows the system to adapt to varying timing conditions in IAB networks while maintaining a relatively simple operational procedure through standardized signaling.
Data Source
AI summary
Embodiments of an integrated access and backhaul (IAB) node, a User Equipment (UE), and methods of communication are generally described herein. An IAB node may operate as a relay between an IAB donor and a UE. The IAB node may receive, from the IAB donor, first signaling that indicates a first timing advance (TA) offset between the IAB donor and the IAB node. The IAB node may determine a second TA offset between the IAB node and the UE. The second TA offset may be based on a timing difference between a transmission time of a downlink frame transmitted to the UE and a reception time of an uplink frame from the UE. The IAB node may transmit, to the UE, second signaling that indicates the first TA offset and the second TA offset.