Content for TS 43.318 Word version: 18.0.0

4.1 GAN A/Gb mode architecture 4.2 GAN Iu mode architecture 5.1 Mobile Station (MS) 5.2 Generic Access Network Controller (GANC)
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4 Architecture p. 13

4.1 GAN A/Gb mode architecture |R8| p. 13

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

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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 TS 48.008.
- Gb-interface for packet switched services as defined in TS 48.018.
- Lb-interface for supporting location services as defined in TS 43.059.
- CBC-BSC interface for supporting cell broadcast services as defined in 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 TS 29.234. 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 |R8| p. 14

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

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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 TS 25.410.
- Iu-ps interface for packet switched services as overviewed in TS 25.410.
- Iu-pc interface for supporting location services as described in TS 25.450.
- Iu-bc interface for supporting cell broadcast services as described in TS 25.419.
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 TS 29.234. 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.

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

5 Functional entities p. 16

5.1 Mobile Station (MS) p. 16

The MS contains a new functional block to access a Generic Access Network (GAN).

5.2 Generic Access Network Controller (GANC) p. 16

5.2.1 GAN A/Gb mode |R8| p. 16

The core network interacts with the Generic Access Network Controller (GANC) as though it was an A/Gb mode BSS. The generic IP access network provides connectivity between the GANC and the MS. The GANC entity inter-works between the A/Gb interfaces and a generic IP access network, using the following functionality:

User plane circuit switched services:
- Reframing of AMR/RTP to AMR/(A-interface framing).
- If non-TrFO, transcoding voice to/from the MS to PCM voice from/to the MSC.
- If TrFO, transcoding maybe required if a common codec cannot be negotiated.
User plane packet switched services:
- Inter-working data transport channels over Up interface to packet flows over Gb interface.
Control plane functionality:
- Security Gateway (SEGW) for the set-up of a secure tunnel to MS for mutual authentication, encryption and data integrity. The SEGW provides a subset of the Wm functions, specifically the authentication procedures.
- Registration for GAN access and providing system information.
- Management of GAN bearer paths for CS and PS services, including the establishment, administration, and release of control and user plane bearers between the MS and the GANC.
- Functionality providing support for paging, handover and PS handover procedures.
- Transparent transfer of L3 messages (i.e. NAS protocols) between the MS and core network.

5.2.2 GAN Iu mode |R8| p. 16

The core network interacts with the Generic Access Network Controller (GANC) as though it was an RNC. The generic IP access network provides connectivity between the GANC and the MS. The GANC entity inter-works between the Iu interfaces and a generic IP access network, using the following functionality:

User plane circuit switched services:
- The interworking of circuit switched user data between the Up interface and the Iu-cs interface
User plane packet switched services:
- The interworking of packet switched user data between the Up interface and the Iu-ps interface
Control plane functionality:
- Security Gateway (SEGW) for the set-up of a secure tunnel to the MS for mutual authentication, encryption and data integrity
- GAN Discovery support and Default GANC assignment
- GAN Registration support including provision of GAN system information to the MS and possible redirection to a different Serving GANC
- Management of GAN bearer paths for CS and PS services, including the establishment, administration, and release of control and user plane bearers between the MS and the GANC
- Functionality providing support for paging and relocation/handover procedures
- Transparent transfer of L3 messages (i.e., NAS protocols) between the MS and core network