ng-voice IMS Application Servers

AGW (Authentication Gateway)

IP-SM-GW (IP Short Message Gateway)

MMTel/TAS (Multimedia Telephony / Telephony Application Server)

Media Resource Function (MRF)

SCC-AS (Service Centralization and Continuity Application Server) / T-ADS (Terminating Access Domain Selection)

LI (Lawful Intercept)

USSD (Unstructured Supplementary Service Data) Gateway

ng-voice IMS Core

P-CSCF

I-CSCF

S-CSCF

E-CSCF (Emergency Call Session Control Function)

BGCF (Breakout Gateway Control Function)

ENUM (E.164 Number Mapping)

ng-voice PCRF

Policy and Charging Function (PCRF)
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The PCRF dynamically allocates and manages bandwidth requirements for various use cases. For VoLTE/VoNR, it is required to provide a better QoS and, in turn, an excellent user experience. The PCRF provides the QoS authorization that decides how a certain data flow will be treated in the PCRF, typically the PGW, and ensures that this follows the user’s subscription profile.
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Main Features of ng-voice's PCRF:

• Support for the Diameter Gx interface with PGW/GGSN as per 3GPP TS 29.210

• Support for the Diameter Rx interface with CSCF as per 3GPP TS 29.214

• Support for Dynamic PCC rules

• Support for both session and bearer binding as per 3GPP TS 23.203 during IMS default and dedicated bearer setup and teardown

• Provision of QoS information

• Support for network-initiated dedicated bearer establishment based on application (e.g., the P-CSCF) request over the Rx interface

• Support for Network Provided Location Information during IMS call-initiation

The PCRF is compliant with 3GPP release 15. Applicable standards include 3GPP TS 29.212, TS 23.203, TS 29.213, and TS 29.214.

ng-voice HSS

HSS (Home Subscriber Server)
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ng-voice provides a software solution for the Home Subscriber Server (HSS), Home Location Register (HLR), Authentication Centre (AuC), and Equipment Identity Register (EIR) functionalities. ng-voice's subscriber database solution supports 3G, 4G, and 5G technologies and VoLTE, VoNR, and VoWiFi services.The HSS is the System Architecture Evolution (SAE)'s central database in LTE networks where important subscriber information is stored. GSM networks have a Home Location Register (HLR) and Authentication Centre (AuC). The equivalent of this in LTE networks is the HSS. The MME/SGSN communicates with the HSS over the S6a/S6d Diameter interface for authentication, location, and service information about the subscriber.Besides LTE, the HSS is also a functional element of IMS/VoLTE. The HSS database supports the IMS network entities that handle calls/sessions. It contains user profiles, performs authentication and authorization of the user, and can provide their location information. From an IMS perspective, the components communicating with the HSS are the Application Servers (AS) and Call State Control Function servers (CSCFs). Upon being queried by the Interrogating-CSCF (I-CSCF) when SIP registration is performed, the HSS retrieves the Serving-CSCF (S-CSCF) address and assigns it to a user. The user's information and profile data are then downloaded from the backend database and stored by the HSS, where the data can be accessed. After successful authentication on the same interface, the S-CSCF downloads the subscriber's profile over the Cx Diameter interface. The profile contains the Initial Filter Criteria providing the logic to the IMS for triggering SIP messages to the appropriate Application Servers. Application Servers (AS) access the HSS over the Sh diameter interface. Besides public identifiers, IMS user identities, and location information, the HSS also stores repository data related to a service (e.g., Supplementary Service data).Furthermore, the Authentication, Authorization, and Accounting (AAA) function communicates with the HSS over the SWx interface to support non-3GPP access to the network for VoWiFi service. ng-voice's subscriber database solution also provides Authentication Centre (AuC) and Equipment Identity Register (EIR) functionalities. The AuC provides authentication parameters (e.g., authentication vectors) for the authentication process. The EIR provides blacklisting/whitelisting functionalities over the S13 interface.
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Main Features of ng-voice’s subscriber database solution:

• Supported interfaces include:
  - S6a and S6d interfaces provide procedures for attaching the device to 3G and 4G packet networks.
  - Cx and Sh interfaces provide procedures for accessing IMS services.
  - SWx interface providing procedures for VoWiFi access.
  - Zh interface provides authentication procedures for Supplementary Service configuration.
  - The S6c interface provides procedures for SMS operations with the HSS.
  - 5G interfaces including Nhss, NU1, NU2, N70 and N71.
  - SS7 MAP interfaces, including MAP C and MAP D, through an additional interworking function, translating S6d to MAP

  Authentication procedures included EPS AKA, IMS AKA, and 5G AKA.

• Provisioning through REST-based APIs.

• User Management through GUI

  Robust and geo-redundant backend database

The HSS is compliant to 3GPP release 17. Applicable standards include 3GPP TS 29.228, 3GPP TS 29.229, TS 24.229, TS 29.328 and TS 29.329.

Supported interfaces include:
- S6a and S6d interfaces, which provide procedures for attaching the device to 3G and 4G packet networks
- Cx and Sh interfaces, which provide procedures for accessing IMS services
- SWx interface, which provides procedures for VoWiFi access
- Zh interface, which provides authentication procedures for Supplementary Service configuration
- S6c interface, which provides procedures for SMS operations with the HSS
- 5G interfaces, including Nhss, NU1, NU2, N70, and N71
- SS7 MAP interfaces, including MAP C and MAP D, through an additional interworking function translating S6d to MAP
- EPS AKA, IMS AKA, and 5G AKA authentication procedures
- Provisioning through REST-based APIs
- User Management through GUI
- Robust and geo-redundant backend database.
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The HSS is compliant with 3GPP release 17. Applicable standards include 3GPP TS 29.228, 3GPP TS 29.229, TS 24.229, TS 29.328, and TS 29.329.

ng-voice ePDG/AAA

ePDG/AAA (Evolved Packet Data Gateway / Authentication Authorization Accounting)
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Operators who want to supplement LTE coverage by offering VoWiFi to their end-users require the addition of an AAA and ePDG to the Packet Core and IMS. Subscribers can then use WiFi to access EPC networks when LTE coverage is unavailable. As there are different access networks in scope, there is a need for handover between VoLTE and VoWiFi to ensure continuity of services. Hence, the handover function is one of the features of our solution. VoWiFi subscribers use the ePDG to attach to an EPC network and then register with the IMS network. The ePDG interworks with the AAA server to authenticate the UEs. After UE authentication, the ePDG forwards messages to the PGW over the S2b interface.m.

Main Features of ng-voice's ePDG/AAA:

• The ePDG communicates with the AAA and PGW, providing signaling and data channels for UEs

• The AAA communicates with the ePDG over the SWm interface to authenticate VoWiFi subscribers

• The AAA communicates with the PGW over the S6b interface and with the HSS over the SWx interface

The ePDG/AAA is compliant with 3GPP release 15. Applicable standards include 3GPP TS 23.402, TS 33.402, TS 29.273, and TS 29.274.