Home NodeB Gateway Function (Interface HNBGWFunction)

Description

The Interface HNBGWFunction (Home NodeB Gateway Function) is a managed function defined within the Generic Network Resources Network Resource Model (NRM) as specified in 3GPP TS 28.673 and TS 32.776. It represents the management view of the Home NodeB Gateway (HNB-GW), a critical network element in the Home NodeB architecture that serves as the aggregation point between multiple Home NodeBs and the core network. The HNBGWFunction provides a standardized object model for managing the HNB-GW within the 3GPP management framework.

In the Home NodeB architecture, the HNB-GW plays a central role by concentrating traffic from many HNBs and presenting a single, consolidated interface to the core network. This architecture was designed to address the scalability challenges of deploying large numbers of home base stations. Without a gateway, each HNB would require individual connections to core network elements such as the MSC, SGSN, and GGSN, which would be impractical for large-scale deployments. The HNB-GW handles the Iuh interface towards HNBs and the Iu interface towards the core network, performing functions such as registration, authentication, and mobility management for home base station users.

The HNBGWFunction, as a managed function, is modeled as a subclass of GenericNetworkResourcesNRMDefs::ManagedFunction. This means it inherits the common management capabilities defined for all managed functions in the Generic Network Resources NRM, including standard attributes for identification, state management, and operational status. The managed function also supports standard operations such as creation, deletion, and modification, as well as notifications for state changes and fault conditions.

From a management perspective, the HNBGWFunction enables the network management system to monitor and control the HNB-GW through standardized interfaces. This includes managing the gateway's configuration parameters, monitoring its performance metrics such as the number of registered HNBs and active sessions, and handling fault management for the gateway itself and the HNBs it serves. The HNBGWFunction may also be associated with other managed objects such as HNBProfile instances that define the characteristics of the HNBs connected to the gateway.

The Generic Network Resources NRM provides the structural framework for the HNBGWFunction. The NRM defines how managed functions are organized within the management information model, including containment relationships and naming conventions. The HNBGWFunction is typically contained within a ManagedElement object, which represents the physical network element hosting the HNB-GW functionality. This hierarchical organization allows management systems to navigate from the network level down to individual managed functions and their associated parameters.

Since its introduction in Release 10, the HNBGWFunction has been part of the 3GPP management standards supporting Home NodeB deployments. Release 10 was a pivotal release for 3GPP management architecture, introducing the Generic Network Resources NRM that provided a more flexible and extensible framework compared to earlier management models. The HNBGWFunction was defined within this framework to ensure that the HNB-GW could be managed in a standardized way, facilitating multi-vendor interoperability and reducing the integration burden on network operators.

Purpose & Motivation

The HNBGWFunction exists to provide a standardized management interface for the Home NodeB Gateway within the 3GPP management architecture. The HNB-GW itself was introduced to solve the scalability problem of connecting large numbers of Home NodeBs directly to the core network. Without a gateway, each HNB would need individual connections to multiple core network elements, creating a mesh of connections that would be operationally complex and expensive to maintain. The HNB-GW aggregates these connections, presenting a single interface to the core network.

The management of the HNB-GW is equally important as its operational function. Network operators need to monitor the health and performance of the gateway, configure its parameters, and manage the HNBs connected to it. The HNBGWFunction provides a standardized way to perform these management tasks, ensuring that management systems from different vendors can interoperate. This is particularly important in multi-vendor environments where the HNB-GW and the management system may come from different suppliers.

Historically, the HNBGWFunction was introduced in Release 10 as part of the Generic Network Resources NRM. This coincided with the widespread deployment of femtocells and the need for standardized management solutions. The 3GPP management architecture was evolving towards the IRP-based approach, which provided a more modular and extensible framework for defining management interfaces. The HNBGWFunction represents the application of this framework to the specific needs of Home NodeB Gateway management, providing a building block that operators can use to build comprehensive management solutions for their femtocell deployments.