Unknown RRC Establishment Cause Handling in NG-RAN
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The 3GPP cellular communications system lacks clear handling mechanisms for unknown Radio Resource Control (RRC) establishment causes, leading to potential inaccuracies in Key Performance Indicators (KPIs) and negative consequences such as rejecting RRC establishment requests when unknown causes are encountered, especially due to version mismatches between User Equipment (UE) and Next Generation Radio Access Network (NG-RAN) nodes.
Innovation Solution
The introduction of a new code point 'Unknown' in the NGAP RRC Establishment Cause Information Element (IE) or using an existing 'notAvailable' code point to indicate unknown RRC establishment causes, allowing for proper handling and indication of unknown causes over the NGAP interface, thereby clarifying ambiguity in existing specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the network node receives an unknown RRC establishment cause value from the UE, then the network node should handle it appropriately, but the existing specifications do not provide clear handling mechanisms, leading to potential inaccuracies in KPIs and negative consequences such as rejecting RRC establishment requests
Solution Approach 1:
The patent introduces a new code point value 'unknown' in the NGAP RRC Establishment Cause Information Element to represent unknown RRC establishment causes. This parameter change allows the network node to explicitly indicate when a UE sends an unknown cause value, enabling appropriate handling without rejecting RRC establishment requests and improving KPI accuracy.
2Loss of information
If a new code point 'Unknown' is introduced in the NGAP RRC Establishment Cause Information Element, then unknown RRC causes can be properly indicated, but the system complexity increases
Solution Approach 1:
The patent modifies the NGAP RRC Establishment Cause Information Element by introducing a new code point value 'unknown' to represent unknown RRC establishment causes. This parameter change enables accurate indication of unknown causes in the NGAP interface, preventing information loss while maintaining backward compatibility with existing specifications.
Data Source
AI summary
Systems and methods are disclosed herein for handling an unknown Radio Resource Control (RRC) establishment cause value in a cellular communications system. In one embodiment, a method performed in a cellular communications system comprises, at a Radio Access Network (RAN) node in a RAN of the cellular communications system, receiving a RRC message from a User Equipment (UE) comprising an unknown establishment cause value and sending a message to a core network node, the message comprising an indication that the unknown cause value is included in the RRC message received from the UE. The method further comprises, at the core network node in a core network of the cellular communications system, receiving the message from the RAN node. In this manner, handling of an unknown RRC cause value over the interface between the RAN node and the core network node is enabled.