O-RU Control Plane Overload Mitigation via Section Dropping
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Solution Overview
Problem
Current wireless communication systems face limitations in the control plane processing capacity on the fronthaul interface, particularly in Open Radio Access Network (O-RAN) deployments, leading to underutilization of processing resources and restrictive configuration options for the Distributed Unit (O-DU) and Radio Unit (O-RU).
Innovation Solution
The proposed solution allows for more flexible utilization of O-RU processing resources by extending the capabilities reported over the O-RAN management plane, enabling the O-DU to temporarily exceed the reported control plane processing capacity of the O-RU. This is achieved by informing the O-RU that it can discard control plane sections when overloaded, ensuring that the overload is limited to a single slot without affecting subsequent slots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the O-DU sends control plane sections to the O-RU based on reported processing capacity, then the O-RU can process all sections without overload, but the processing resources are underutilized and spectral efficiency is reduced
Solution Approach 1:
The O-DU is allowed to send more control plane sections to the O-RU than the reported processing capacity, exceeding the guaranteed capacity by a configured factor. The O-RU processes as many sections as possible within the slot, accepting that some sections may be dropped during overload conditions. This partial action approach improves resource utilization while maintaining acceptable reliability through configured safety margins.
Solution Approach 2:
The system introduces a new parameter - the overload mitigation configuration factor - that modifies the relationship between reported capacity and actual sending capacity. By changing this parameter, the O-DU can dynamically adjust how much excess traffic to send based on network conditions, transforming a static capacity limitation into a flexible,可调 parameter that optimizes both reliability and productivity.
2Reliability
If the O-DU is restricted to the reported control plane processing capacity, then the O-RU processing is reliable, but the configuration options are restrictive and resource utilization is low
Solution Approach 1:
The system transforms the static capacity reporting mechanism into a dynamic one by introducing configurable overload mitigation parameters. The O-DU can now adapt its sending behavior based on network conditions, traffic priorities, and the configured factor, making the system flexible rather than rigid. This dynamic approach maintains reliability through configurable safety margins while providing adaptability in response to changing network conditions.
Solution Approach 2:
The overload mitigation configuration enables the O-RU to serve multiple functions: it can process control plane sections up to its guaranteed capacity, handle excess sections when configured to do so, and selectively drop sections during overload. This multi-functionality allows the same hardware to operate in different modes depending on network conditions, providing both conservative reliable operation and aggressive resource utilization as needed.
3Productivity
If the O-RU discards control plane sections during overload, then subsequent slots are not affected, but some control plane sections are lost in the overloaded slot
Solution Approach 1:
The harmful effect of overload is extracted and isolated to specific control plane sections that are dropped during overload conditions. By selectively removing only the excess sections that cause the overload rather than reducing the entire system capacity, the patent ensures that subsequent slots can operate at full capacity. This extraction approach limits the impact of overload to minimal section loss while preserving overall system productivity.
4Productivity
If the O-DU uses more aggressive packet scheduling to utilize O-RU capacity, then spectral efficiency improves, but the control plane processing capacity may be exceeded
Solution Approach 1:
The system implements feedback through the capability reporting mechanism where the O-RU informs the O-DU of its processing capacity and the configured overload mitigation factor. The O-DU uses this feedback to calculate appropriate sending rates that utilize O-RU capacity aggressively while respecting the configured safety margins. This feedback loop enables aggressive scheduling that improves spectral efficiency while maintaining reliability through informed capacity management.
Data Source
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AI summary
Disclosed is a method comprising transmitting, by an apparatus, to a distributed unit, information indicating one or more capabilities of the apparatus, wherein the one or more capabilities comprise at least a capability for mitigating an overload of a control plane processing capacity of the apparatus in a slot; and receiving, by the apparatus, from the distributed unit, based on transmitting the information, one or more messages comprising a plurality of control plane sections to be processed in one or more slots.