Capacity and Coverage Optimization Policy Control Function

Description

The CCO Policy Control Function is a logical entity within the 3GPP Self-Organizing Networks (SON) management architecture, specifically designed to handle Capacity and Coverage Optimization (CCO). It is defined in 3GPP specifications 28.628 (Self-Organizing Networks (SON) Policy Network Resource Model (NRM) Integration Reference Point (IRP)) and 32.522 (Self-Organizing Networks (SON) Policy Network Resource Model (NRM) Integration Reference Point (IRP)). This function is responsible for configuring the policies that govern how the network optimizes its capacity and coverage. It acts as a policy decision point, providing rules and thresholds that guide the CCO algorithms in the network elements.

In the SON architecture, the CCO Policy Control Function interacts with the Network Resource Model (NRM) to manage the configuration of CCO policies. It allows the operator to define high-level objectives, such as prioritizing coverage over capacity in certain areas, or setting thresholds for load balancing. These policies are then translated into specific actions by the CCO function, which may reside in the Element Manager (EM) or the Network Manager (NM). The function ensures that the optimization process aligns with the operator's business and operational policies.

The CCO Policy Control Function operates by receiving policy inputs from the operator or higher-level management systems. It then distributes these policies to the relevant network entities, such as eNodeBs or gNodeBs, which execute the CCO algorithms. The policies can include parameters like the maximum allowed transmit power, handover margins, and load thresholds. By centralizing policy control, the function ensures consistency across the network and avoids conflicting optimization actions.

Key components of the CCO Policy Control Function include the policy repository, which stores the defined policies; the policy evaluation engine, which interprets the policies and generates configuration parameters; and the policy enforcement interface, which communicates with the network elements. The function also supports policy conflict resolution, ensuring that multiple policies do not lead to contradictory actions. It is typically implemented as part of the Element Manager or Network Manager, leveraging the Itf-N interface for communication.

The CCO Policy Control Function plays a critical role in enabling autonomous network operations. It allows operators to define high-level intents, such as 'improve coverage in rural areas' or 'balance load in urban hotspots', without manually configuring each cell. This reduces operational expenditure and improves network performance. As networks evolve towards 5G and beyond, the function continues to be relevant, adapting to new radio technologies and denser deployments.

Purpose & Motivation

The CCO Policy Control Function was introduced to address the growing complexity of mobile networks, where manual optimization of capacity and coverage became impractical. With the advent of Self-Organizing Networks (SON) in 3GPP Release 8 and beyond, there was a need for automated mechanisms to manage network performance. The CCO Policy Control Function provides a standardized way to define and enforce policies that guide these automated optimizations, ensuring they align with operator objectives.

Before the introduction of SON and the CCO Policy Control Function, network optimization was largely manual, relying on drive tests and expert analysis. This was time-consuming, expensive, and could not keep up with the dynamic nature of traffic and radio conditions. The CCO Policy Control Function solves this by enabling policy-based automation, where the network can adjust itself according to predefined rules. It also allows for multi-vendor interoperability, as the policies are standardized across different network elements.

The function was motivated by the need to reduce Operational Expenditure (OPEX) and improve network efficiency. By automating capacity and coverage optimization, operators can respond quickly to changing conditions, such as traffic surges or cell outages. The policy control aspect ensures that these automated actions do not violate operator constraints, such as regulatory requirements or business priorities. This makes the CCO Policy Control Function a key enabler for the autonomous network vision of 5G and future generations.