Endpoint Information Exchange for CRAN Transmission Paths
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Solution Overview
Problem
In cloud radio access networks (CRAN) with separated functions between control and data units, existing communication methods are no longer applicable due to increased interfaces, leading to challenges in establishing and managing user and control planes effectively.
Innovation Solution
A communication method that involves obtaining and exchanging endpoint information between access network nodes to establish transmission paths corresponding to DRBs, allowing for the separation of user and control plane functions and enabling the configuration of protocol layers for efficient data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If functions of an access network device are separated into CU and DU units, then adaptability and versatility are improved, but device complexity increases due to increased interfaces
Solution Approach 1:
The access network device is segmented into CU (Central Unit) and DU (Distributed Unit) with distinct functional responsibilities. The CU handles control plane functions including RRC, PDCP, and part of RLC layers, while the DU handles user plane functions including part of RLC, MAC, and PHY layers. This segmentation improves adaptability by allowing independent optimization of control and data processing functions.
Solution Approach 2:
An F1 interface is introduced as an intermediary communication channel between CU and DU units. This standardized interface includes F1-C for control plane communication and F1-U for user plane communication, providing a structured mechanism for information exchange and reducing the complexity of direct point-to-point connections.
2Adaptability or versatility
If functions of an access network device are separated into CU and DU units, then adaptability is improved, but ease of operation deteriorates due to increased interfaces
Solution Approach 1:
The F1 interface is designed as a universal communication mechanism that handles multiple functions including bearer establishment, data transmission, and control signaling between CU and DU. This multi-functional interface reduces the need for separate dedicated interfaces for each function, simplifying operation despite functional separation.
Solution Approach 2:
The control plane interface F1-C implements feedback mechanisms where the CU receives status information and control responses from the DU, enabling automated management of bearers and resources. This feedback loop reduces manual intervention requirements and maintains ease of operation.
3Device complexity
If existing communication methods are used in CRAN with separated functions, then device complexity is maintained, but reliability deteriorates due to inapplicability of existing solutions
Solution Approach 1:
The patent establishes bearer transmission paths and configures protocol layers in advance before actual data transmission begins. The CU pre-configures RLC, PDCP, and other layer parameters, and pre-establishes the F1 interface connections with the DU, ensuring reliable communication from the outset rather than attempting to adapt existing post-hoc solutions.
Solution Approach 2:
The patent introduces new communication parameters and protocols specifically designed for the CU-DU architecture, including F1 interface signaling formats, bearer configuration parameters, and layer interaction protocols. These parameter changes enable reliable communication tailored to the separated functional architecture rather than forcing compatibility with legacy unified base station protocols.
Data Source
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AI summary
This application provides a communications method and apparatus, and a radio access network, to be applicable to a scenario in which functions of an access network device are separate. The method includes: obtaining, by a first access network node from a second access network node, endpoint information of a second transmission path on the second access network node side, where the second transmission path is a transmission path that is between the second access network node and a third access network node and that is corresponding to a DRB; obtaining, by the first access network node from the third access network node, endpoint information of the second transmission path on the third access network node side; sending, by the first access network node to the second access network node, the endpoint information of the second transmission path on the third access network node side; and sending, by the first access network node to the third access network node, the endpoint information of the second transmission path on the second access network node side.