CRAN Buffer Status Feedback for State Switching
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Solution Overview
Problem
In a cloud radio access network (CRAN) architecture, the separation of control and data units (CU and DU) hinders the perception of buffer status changes by the CU, preventing timely state switching and high-throughput configuration in 5G systems, as the CU cannot detect changes in the terminal device's data volume or key changes.
Innovation Solution
A data transmission method where the first network node receives a buffer status report from the terminal device and sends indication information to the second network node about the uplink data volume, allowing the second network node to perform state switching or radio bearer offloading, and includes mechanisms for the terminal device to change keys and notify the network of random access procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If the CU and DU are separated in CRAN architecture, then the network can achieve centralized control and distributed unit functions, but the CU cannot timely perceive buffer status changes and state switching of terminal devices
Solution Approach 1:
The patent implements a feedback mechanism where the DU receives buffer status reports from terminal devices and promptly forwards this information to the CU through the F1 interface. This ensures the CU receives real-time feedback about buffer status changes, enabling timely state switching decisions without the time delay that would occur with passive information gathering.
Solution Approach 2:
The DU acts as an intermediary between the terminal device and the CU. It receives buffer status reports from the terminal, processes this information locally, and then transmits it to the CU. This intermediary role allows the CU to be informed of buffer status changes in a timely manner while maintaining the functional separation between CU and DU.
2Reliability
If the CU instructs terminal device to change key, then security processing can be updated, but the CU fails to decrypt data sent before the switching command is received
Solution Approach 1:
The patent implements preliminary action by having the terminal device send an indication message to the DU before actually changing the encryption key. This allows the CU to receive advance notification of the upcoming key change, prepare the necessary decryption keys in advance, and ensure continuous decryption capability without interruption when the key change takes effect.
Solution Approach 2:
The system uses feedback mechanisms where the terminal device notifies the network (through the DU) about key changes before they occur. This feedback loop allows the CU to stay informed of security updates and maintain the ability to decrypt data seamlessly, resolving the contradiction between security updates and data decryption continuity.
3Adaptability or versatility
If the CU separates from DU, then the network architecture becomes more flexible and scalable, but the CU cannot perceive data volume changes and perform high-throughput multi-connection configuration in time
Solution Approach 1:
The patent establishes a feedback mechanism where the DU receives buffer status reports from terminal devices and immediately forwards this information to the CU. This real-time feedback loop enables the CU to perceive data volume changes promptly and trigger high-throughput multi-connection configurations without delay, maintaining productivity despite the architectural separation.
Solution Approach 2:
The system implements preliminary action by having the DU prepare and forward buffer status information to the CU in advance of actual data transmission needs. This allows the CU to pre-configure high-throughput paths and connection resources, enabling rapid state switching and maintaining high productivity while preserving architectural flexibility.
Data Source
AI summary
The present disclosure relates to data transmission methods, network devices. One example data transmission method includes: a first network node sends a first indication information to a second network node, the first indication information includes information about an uplink data volume of a buffer of a terminal device, or the first indication information indicates a relationship between an uplink data volume of a buffer of a terminal device and a predefined data volume threshold.