4 Architecture

3GPP43.318Generic Access Network (GAN)Release 16Stage 2TS

4.1 GAN A/Gb mode architecture

The Generic Access Network A/Gb mode functional architecture is illustrated in figure 1.

Figure 1: GAN A/Gb mode functional architecture

The main features of the GAN A/Gb mode architecture are:

– New entities, and entities with enhanced functionality:

– Mobile Station (MS).

– Generic Access Network Controller (GANC). The GANC appears to the core network as a GERAN Base Station Subsystem (BSS). It includes a Security Gateway (SEGW) that terminates secure remote access tunnels from the MS, providing mutual authentication, encryption and data integrity for signalling, voice and data traffic.

– A Generic IP Access network provides connectivity between the MS and the GANC. The IP transport connection extends from the GANC to the MS. A single interface, the Up interface, is defined between the GANC and the MS.

– Co-existence with the GSM/GPRS Radio Access Network (GERAN) and interconnection with the Core Network (CN) via the standardized interfaces defined for GERAN A/Gb mode:

– A-interface for circuit switched services as defined in 3GPP TS 48.008 [13].

– Gb-interface for packet switched services as defined in 3GPP TS 48.018 [16].

– Lb-interface for supporting location services as defined in 3GPP TS 43.059 [17].

– CBC-BSC interface for supporting cell broadcast services as defined in 3GPP TS 23.041

– Transaction control (e.g. CC, SM) and user services are provided by the core network (e.g. MSC/VLR and the SGSN/GGSN).

– Use of AAA server over the Wm interface as defined by 3GPP TS 29.234 [8]. The AAA server is used to authenticate the MS when it sets up a secure tunnel. Note that only a subset of the Wm functionalities is required for the GAN application. As a minimum the GANC-SEGW shall support the Wm authentication procedures.

Indication of support for PS Services and of support for DTM is provided through appropriate signalling to the MS.

4.2 GAN Iu mode architecture

The Generic Access Network Iu mode functional architecture is illustrated in figure 1a.

Figure 1a: GAN Iu mode functional architecture

The main features of the GAN Iu mode architecture are:

– Entities with enhanced functionality:

– Mobile Station (MS). The functionality of the MS defined for GAN A/Gb mode is modified to support GAN Iu mode operation. The MS may support GAN Iu mode operation, GAN A/Gb mode operation, or both. Mode selection is performed during registration.

– Generic Access Network Controller (GANC). The functionality of the GANC defined for GAN A/Gb mode is modified so as to appear to the core network as a UTRAN Radio Network Controller (RNC). As for GAN A/Gb mode, the GANC includes a Security Gateway (SEGW) that terminates secure remote access tunnels from the MS, providing mutual authentication, encryption and data integrity for signalling, voice and data traffic.

– A generic IP access network provides connectivity between the MS and the GANC. The IP transport connection extends from the GANC to the MS. A single interface, the Up interface, is defined between the GANC and the MS. Functionality is added to this interface, over that defined for GAN A/Gb mode, to support the GAN Iu mode service.

– Co-existence with the UMTS Terrestrial Radio Access Network (UTRAN) and interconnection with the Core Network (CN) via the standardized interfaces defined for UTRAN:

– Iu-cs interface for circuit switched services as overviewed in 3GPP TS 25.410 [45].

– Iu-ps interface for packet switched services as overviewed in 3GPP TS 25.410 [45].

– Iu-pc interface for supporting location services as described in 3GPP TS 25.450 [52].

– Iu-bc interface for supporting cell broadcast services as described in 3GPP TS 25.419 [51].

– Transaction control (e.g. CC, SM) and user services are provided by the core network (e.g. MSC/VLR and the SGSN/GGSN).

– Use of AAA server over the Wm interface as defined by 3GPP TS 29.234 [8]. The AAA server is used to authenticate the MS when it sets up a secure tunnel. Note that only a subset of the Wm functionalities is required for GAN Iu mode. As a minimum the GANC-SEGW shall support the Wm authentication procedures.

A GANC implementation may simultaneously support both GAN A/Gb mode and GAN Iu mode operation; the interfaces associated with both modes of operation are shown in the following figure.

Figure 1b: Simultaneous GAN A/Gb mode and GAN Iu mode functional architecture