IAB Network Control Plane Latency Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated Access Backhaul (IAB) networks in 5G systems experience lower performance levels due to multi-hop transmission delays, which impact critical functions like handover and radio link failures, compared to non-IAB networks.
Innovation Solution
Implementing pre-allocation of resources and optimizing Random Access Channel (RACH) handling and contention-based physical uplink shared channel (CB-PUSCH) transmission to minimize delays in multi-hop IAB networks by predicting and allocating resources for uplink transmissions and using orthogonal cover codes for control plane SRs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multi-hop transmission is used in IAB networks, then network coverage and connectivity are improved, but transmission latency increases
Solution Approach 1:
The patent implements pre-allocation of uplink resources for IAB nodes in multi-hop networks. By预先 allocating time-frequency resources and configuring uplink grants before data transmission is needed, the system eliminates the time required for resource request and allocation procedures during actual data transfer, thereby reducing transmission latency while maintaining extended network coverage through multiple hops
2Loss of time
If resource pre-allocation is implemented, then transmission delays are reduced, but control plane complexity increases
Solution Approach 1:
The patent reuses existing uplink grant structures and resource allocation mechanisms from standard LTE/NR protocols for the pre-allocation process in IAB networks. By adapting existing control plane procedures rather than creating entirely new mechanisms, the system reduces transmission delays through pre-allocation while minimizing the increase in control plane complexity
Solution Approach 2:
The patent performs resource pre-allocation during initial IAB node configuration and setup phases, establishing uplink grants and time-frequency resource assignments in advance. This preliminary action eliminates the need for repeated resource request-exchange procedures during data transmission, reducing latency while concentrating control plane complexity in the initial configuration phase rather than ongoing operations
3Reliability
If hopping patterns are used in IAB networks, then frequency diversity is improved, but performance of critical functions deteriorates
Solution Approach 1:
The patent pre-allocates uplink resources and configures hopping patterns in advance for IAB nodes, so that when handover or critical transmissions are needed, the nodes can immediately use pre-configured resources without waiting for resource allocation procedures. This maintains frequency diversity through hopping while reducing handover time by eliminating resource setup delays
Data Source
AI summary
Systems and methods of reducing control plane latency in a 5G IAB network are described. SRs transmitted between nodes indicate that a control plane PDU is to be transmitted. The SRs use periodic resources or OCCs reserved for control plane signaling and are initiated by an RRC message or RACH from the UE. The SRs are initiated if the LCD field in the MAC sub header of the RRC message indicates the CCCH or the DCCH logical channel. If the PDU is available after the original resource, a resource is used that is provided via another grant, which is periodically provided or automatically initiated due to failure to transmit on the original grant. The SR or RRC message can also specify a delayed timeslot for the grant. For contention-based procedures the RACH preamble is randomly selected or selected from among a set of RACH preambles assigned for RRC procedures.