E-UTRAN Cell Network Management Centralized Self-Organizing Network Interface

Description

The EUtranCellNMCentralizedSON interface is a standardized network management interface defined by 3GPP for the centralized Self-Organizing Network (SON) functionality in E-UTRAN (Evolved Universal Terrestrial Radio Access Network). It is part of the Integration Reference Point (IRP) framework and is specified in 3GPP TS 28.659 and TS 32.766. This interface allows a central SON entity (typically located in the Network Manager, NM) to manage and coordinate SON functions across multiple E-UTRAN cells. Centralized SON is one of the three SON architectures defined by 3GPP: centralized, distributed, and hybrid. In the centralized approach, the SON algorithms run in the NM, which collects performance measurements and configuration data from the Element Manager (EM) or directly from network elements (eNBs) and then issues configuration commands back to the network.

The interface operates over the Itf-N reference point between the NM and the EM. It provides operations for reading and writing attributes of the EUtranCellNMCentralizedSON managed object, which represents the SON capabilities of a specific E-UTRAN cell. The managed object is defined in the Generic Network Resources NRM (Network Resource Model) as a subclass of Top. The interface supports functions such as:

- Retrieving SON-related parameters and status from the cell. - Setting SON policies and thresholds. - Triggering SON actions (e.g., mobility robustness optimization, load balancing, energy saving). - Monitoring the outcome of SON actions through notifications and performance data.

The EUtranCellNMCentralizedSON interface is crucial for automating network operations, reducing operational expenditure (OPEX), and improving network performance and stability. It enables the central SON entity to have a holistic view of the network, which is essential for resolving conflicts between different SON functions and ensuring consistent optimization across the entire network. The interface is designed to be vendor-agnostic, allowing multi-vendor integration.

In terms of protocol, the interface typically uses the 3GPP IRP technology, which can be mapped to CORBA, SOAP, or RESTful HTTP. The specific protocol mapping is defined in the respective IRP solution sets. The interface has been part of 3GPP specifications since Release 10 and has been maintained through subsequent releases, ensuring backward compatibility and continuous support for evolving SON use cases.

The EUtranCellNMCentralizedSON interface is a key enabler for the centralized SON architecture, which is particularly beneficial for coordinating SON functions that require a network-wide view, such as inter-cell interference coordination, mobility load balancing, and coverage and capacity optimization. It complements distributed SON functions that run locally in the eNB, and hybrid SON architectures that combine both centralized and distributed approaches.

Purpose & Motivation

The EUtranCellNMCentralizedSON interface was created to support the centralized SON architecture in LTE networks. As networks became more complex with the introduction of heterogeneous deployments (macro, pico, femto cells), manual optimization became impractical and costly. SON was introduced in 3GPP Release 8 to automate network planning, configuration, optimization, and healing. While distributed SON (running in the eNB) can handle fast, local optimizations, some SON functions require a broader view of the network to avoid conflicts and achieve global optimization. The centralized SON approach addresses this by placing SON algorithms in the NM, which can coordinate across multiple cells and vendors. The EUtranCellNMCentralizedSON interface provides the standardized means for the NM to interact with the E-UTRAN cell's SON functionality, ensuring interoperability between different vendors' equipment and management systems. It solves the problem of vendor lock-in and enables operators to deploy multi-vendor SON solutions. The interface also supports the evolution towards more automated networks, including the integration with 5G and network slicing, where centralized SON can play a role in end-to-end optimization.