The 3^rd Generation Partnership Project (3GPP) has agreed the standard for Home NodeB (HNB) architecture for femtocell-to-core network connectivity.

The agreed 3GPP HNB architecture follows an access network-based approach, leveraging the existing Iu-cs and Iu-ps interfaces into the core service network.  The architecture defines two new network elements, the HNB (a.k.a. Femtocell) and the HNB Gateway (a.k.a. Femto Gateway).  Between these elements is the new Iu-h interface.

*        Home NodeB (HNB) - Connected to an existing residential broadband service, an HNB provides radio coverage for standard 3G handsets within a home.  HNBs incorporate the capabilities of a standard NodeB as well as the radio resource management functions of a standard Radio Network Controller (RNC). 
*        HNB Gateway (HNB-GW): Installed within an operator's network, the HNB Gateway aggregates traffic from a large number of HNBs back into an existing core service network through the standard Iu-cs and Iu-ps interfaces.
*        Iu-h Interface: Residing between an HNB and HNB-GW, the Iu-h interface includes a new HNB application protocol (HNBAP) for enabling highly-scalable, ad-hoc HNB deployment.  The interface also introduces an efficient, scalable method for transporting Iu control signaling over the Internet. 

Having an agreed architecture marks a major milestone towards the completion of a global 3G femtocell standard.

"Developing an industry-wide standard requires a tremendous amount of cooperation between vendors and operators, with all parties contributing their knowledge and experience in order to develop the best possible solution," said Patrick Tao, Kineto's vice president of technology.  "The femtocell standardisation effort within 3GPP provides a great example of such cooperation, with the agreed architecture merging key attributes of the 3GPP UMA/GAN-based approach proposed by Kineto with other company proposals to create an optimised architecture capable of supporting mass-market femtocell deployments."

3G femtocell developer Ubiquisys was the first femtocell vendor to announce its commitment to the 3GPP's Iuh interface and will support this interface in its products ready for the planned approval of Iuh in December 2008.