The configuration of the Home NodeB Subsystem is presented in
Figure 5.17-1. In the Figure, all the functions are considered implemented in different logical nodes. If two logical nodes are implemented in the same physical equipment, the relevant interfaces may become internal to that equipment.
The Home NodeB Gateway may also be used only for the control plane of Iu-CS and/or Iu-PS interfaces. In this case, the user plane of Iu-CS and/or Iu-PS interfaces is directly between the Home NodeB and respectively the MSC/VLR and the SGSN/Serving GW/GGSN.
In case Direct Tunnel is established, the user plane is directly between the Home NodeB Subsystem and the GGSN or Serving GW nodes.
The configuration of Home eNodeB Subsystem with a Home eNodeB Gateway present is shown in
Figure 5.17-2. In the Figure, all the functions are considered implemented in different logical nodes. If two logical nodes are implemented in the same physical equipment, the relevant interfaces may become internal to that equipment.
The presence of Home eNodeB Gateway in the configuration of Home eNodeB Subsystem is optional.
The Home eNodeB Gateway may also be used only for the S1-MME interface. In this case, the S1-U interface is directly between the Home eNodeB and the S-GW.