Random Access Response Windows for Multi-TAG Wireless Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In non-ideal backhaul environments, the delay in receiving a Random Access Response (RAR) in a wireless communication system can vary per Timing Advance Group (TAG), leading to improper reception of RARs when using a single response window, especially in multi-TRP scenarios.
Innovation Solution
Configuring separate RACH configurations for each Timing Advance Group (TAG) based on their respective Physical Cell Identities (PCIs), determining the length of reception windows using specific response window parameters, and receiving RARs via dedicated Physical Downlink Control Channels (PDCCH) and Physical Downlink Shared Channels (PDSCH) to stabilize the reception of second TAs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single response window is used for RAR reception in multi-TRP scenarios, then the system complexity is reduced, but the RAR reception reliability deteriorates due to varying delays per TAG in non-ideal backhaul environments
Solution Approach 1:
The patent divides the single response window into multiple TAG-specific response windows (first response window for first TAG, second response window for second TAG). This segmentation allows each TAG to have its own tailored reception timing, accommodating the varying backhaul delays in non-ideal environments while maintaining manageable system complexity through structured organization.
Solution Approach 2:
The patent applies different response window configurations to different TAGs based on their specific delay characteristics. Each TAG receives a response window tailored to its particular backhaul delay requirements, rather than using a uniform configuration for all TAGs, thereby optimizing RAR reception reliability for each local condition.
2Reliability
If separate RACH configurations are configured for each TAG, then the RAR reception reliability is improved, but the device complexity increases
Solution Approach 1:
The patent segments the RACH configuration into TAG-specific configurations (first RACH configuration for first TAG, second RACH configuration for second TAG). This segmentation enables precise control over RAR reception timing for each TAG, improving reliability while organizing the complexity into manageable, structured components rather than unmanaged complexity.
Solution Approach 2:
The patent changes the response window parameter (length and timing) based on the specific TAG and its associated backhaul delay characteristics. By adjusting these parameters dynamically for each TAG, the system achieves high RAR reception reliability without requiring complete redesign of the overall RACH architecture.
3Ease of operation
If a unified response window is used, then the ease of operation is maintained, but the loss of time occurs due to RAR not being received properly for specific TAGs
Solution Approach 1:
The patent segments the response window into TAG-specific windows, allowing each TAG to be monitored at its optimal reception time. This prevents the time loss that would occur with a unified window, as each TAG's RAR can be received properly without waiting for or being delayed by other TAGs' timing requirements.
Solution Approach 2:
The patent establishes TAG-specific response window configurations in advance, before the actual RAR reception occurs. This preliminary configuration ensures that each TAG has its reception timing pre-optimized, eliminating the need for complex real-time adjustments and maintaining ease of operation while preventing time loss.
Data Source
Figure 1~3
Figure 4~5
AI summary
A method according to an embodiment of the present disclosure comprises the steps of: receiving configuration information; transmitting a PRACH; and receiving an RAR on the basis of a window related to the RAR. The configuration information includes i) a first RACH configuration related to a PCI of a serving cell and ii) a second RACH configuration related to an additional PCI. The RAR is related to one of two TAGs. The PCI is related to a first TAG, and the additional PCI is related to a second TAG. On the basis that the PRACH is related to the additional PCI, a length of the window is determined on the basis of a response window parameter related to the second RACH configuration.