5G Fixed Mobile Convergence

Course Outline : This course starts with non-3GPP access to the EPC with its two applications to first understand convergence in 4G :
• One of the applications foreseen is to offload data traffic from 4G to Wi-Fi. This scenario is called Trusted WiFi or Carrier WiFi. Offload enables to transfer part of the mobile data traffic from mobile users to a fixed broadband network via WiFi cells connected to EPC. This solution enables strong mobile network authentication when accessing the EPC via WiFi, as well as data session mobility between WiFi and LTE and vice versa. Furthermore, the user may access to all his mobile data services. With Carrier WiFi, the user may activate all his APNs (e.g., Internet, IMS, etc.) as if he were with mobile radio.
• Another important application is considered called non-Trusted WiFi where the user makes use of EPC only for his IMS related APNs for a service called VoWiFi or WiFi Calling. The client uses WiFi to directly access to his Internet services without going through EPC and WiFi calling via EPC to access to his telephony services including, voice over IP and SMS over IP. The user is connected to EPC via WiFi for WiFi calling and accesses to the IMS architecture. Furthermore handover between VoLTE and VoWiFi is ensured to provide voice call continuity. WiFi calling enables the user access to his telephony services via WiFi when the mobile radio coverage is absent or does not offer a high signal strength.

The course also presents non-trusted and trusted non-3GPP access to the 5GC.

Fixed Wireless Access (FWA) initially offered by mobile operators in 4G is evolving with 5G. 5G FWA is a technology that leverages 5G mobile networks to provide a very high-speed fixed Internet connection. The end customer, via a fixed CPE integrating a 5G modem and via a 5G mobile network, can access the Internet at very high speed. 5G FWA plays a critical role in accelerating broadband coverage. It facilitates the rapid expansion of high-speed Internet access, particularly in rural areas or areas poorly served by existing wired infrastructure. This technology helps bridge the digital divide and provide equitable opportunities for all businesses, regardless of location. FWA is a fixed service offered via the mobile network. FWA 5G is introduced in this course.

5G SA offers a convergent 5G core network (5GC) independent of any type of access. It may support cellular access (NG-RAN), satellite access in the NTN (Non-Terrestrial Network) context, non-trusted and trusted WLAN access and fixed access (e.g., FTTH, cable, xDSL). The convergent 5GC is presented with all the possible access technologies connecting to the 5GC.

If a UE has simultaneous access to WLAN via fixed access and 5G-RAN, it may establish a Multi-Access (MA) PDU session in the 5GS which is associated to user plane resources over 3GPP (5G-RAN) access and WLAN access in parallel and may distribute the PDU session flows over both accesses.

Today's wireline and cellular infrastructures are served by completely disparate core networks, which have their own distinct control plane, user plane and service delivery functions. These functions include authentication, accounting, IP address management, policy control and lawful interception. With most operators worldwide supporting both access technologies, a clear migration path to fixed and mobile convergence at the core network level will simplify provisioning and reduce capital and operating expenses. This convergence is called WWC (Wireline Wireless Convergence) and corresponds to a partnership project of 3GPP, Broadband Forum (BBF) and CableLabs where the 5G core network connects fixed accesses to replace the fixed core network. In addition, Internet access, IMS and IP TV services for landline customers are provided by mobile service platforms.

1. Non-3GPP access to the EPC
1.1. Scenarios
1.1.1. Non-trusted non-3GPP access to the EPC for VoWiFi
1.1.2. Trusted non-3GPP access to the EPC for data offload and VoWiFi
1.2. Non-trusted non-3GPP access to the EPC
1.2.1. Architecture
1.2.2. Interfaces
1.2.2.1. SWu between UE and ePDG : IKEv2 (Control Plane) and IPSec (User Plane)
1.2.2.2. S2b between ePDG and PDN GW : GTPv2-C (Control Plane) and GTP-U (User Plane)
1.2.2.3. SWx between 3GPP AAA Server and HSS : DIAMETER
1.2.2.4. SWm between ePDG and 3GPP AAA Server : DIAMETER
1.2.2.5. S6b between PDN GW and 3GPP AAA Server : DIAMETER
1.2.2.6. Gx between PDN GW/PCEF and PCRF
1.2.2.7. End to End QoS : WMM, DiffServ, QCI
1.2.3. Procedures
1.2.3.1. UE Registration : Authentication and IMS APN activation on non-trusted non-3GPP access to the EPC
1.2.3.2. UE re-authentication
1.2.3.3. UE-initiated Deregistration
1.2.3.4. Administrative deregistration initiated by HSS
1.2.3.5. Profile update by HSS
1.2.3.6. Handover from non-trusted non-3GPP access to E-UTRAN
1.2.3.7. Handover from E-UTRAN to non-trusted non-3GPP access
1.2.3.8. Handover between non-trusted non-3GPP access points connected to the EPC
1.2.3.9. Resource reservation for VoWiFi call
1.3. Trusted non-3GPP access to the EPC
1.3.1. Architecture
1.3.2. Interfaces
1.3.2.1. STa between TWAG and 3GPP AAA Server : DIAMETER
1.3.2.2. S2a between TWAG and PDN GW : GTPv2-C (Control Plane) and GTP-U (User Plane)
1.3.3. Procedures
1.3.3.1. UE registration
1.3.3.2. Internet and IMS APNs activation
1.3.3.3. UE-initiated deregistration
1.3.3.4. Handover from trusted non-3GPP access to E-UTRAN
1.3.3.5. Handover from E-UTRAN to trusted non-3GPP access

2. eMBB and FWA
2.1. Introduction to eMBB and FWA
2.2. FWA in 4G
2.3. FWA in 5G NSA Option 3X
2.4. FWA in 5G SA
2.4.1. eMBB network slice instance for FWA

3. Convergent 5GC
3.1. Objectives
3.2. Access types connected to 5GC
3.2.1. NTN
3.2.2. 5G-RAN
3.2.3. Non-trusted non-3GPP AN
3.2.4. Trusted non-3GPP AN
3.2.5. Fixed AN (e.g., xDSL, Cable, FTTH)
3.3. Network architecture
3.3.1. Interworking entities for non-3GPP Access Networks (AN)
3.3.2. N3IWF for non-trusted non-3GPP AN
3.3.3. TNGF for trusted non-3GPP AN
3.3.4. W-AGF for fixed AN
3.4. Interfaces
3.4.1. NAS N1 between UE and 5GC
3.4.2. N2 between any access and 5GC for the control plane
3.4.3. N3 between any access and 5GC for the user plane
3.5. N6 for IP connectivity towards the external IP networks

4. Non-3GPP access to the 5GC
4.1. Scenarios
4.1.1. Non-trusted non-3GPP access to the 5GC
4.1.2. Trusted non-3GPP access to the 5GC
4.1.2.1. Non 5G capable over WLAN (N5CW) device : Device not supporting NAS N1 with 5GC
4.1.2.2. 5G capable UE : UE supporting NAS N1 with 5GC
4.2. Non-trusted non-3GPP access to the 5GC
4.2.1. Architecture
4.2.2. Interfaces
4.2.2.1. NWu between UE and N3IWF : IKEv2 (Control Plane) and IPSec (User Plane)
4.2.2.2. End to End QoS
4.2.3. Procedures
4.2.3.1. UE Registration and authentication
4.2.3.2. IMS PDU Session establishment
4.2.3.3. UE re-authentication
4.2.3.4. UE-initiated Deregistration
4.2.3.5. Handover from non-trusted non-3GPP access to 5G-RAN
4.2.3.6. Handover from 5G-RAN to non-trusted non-3GPP access
4.2.3.7. Handover between non-trusted non-3GPP access points connected to the 5GC
4.2.3.8. Resource reservation for VoWiFi call
4.3. Trusted non-3GPP access to the 5GC
4.3.1. Architecture
4.3.2. Interfaces
4.3.2.1. NWt between UE and TNGF
4.3.2.2. End to End QoS
4.3.3. Procedures
4.3.3.1. UE Registration and authentication
4.3.3.2. Internet and IMS PDU Sessions establishment
4.3.3.3. UE re-authentication
4.3.3.4. UE-initiated Deregistration
4.3.3.5. Handover from trusted non-3GPP access to 5G-RAN
4.3.3.6. Handover from 5G-RAN to trusted non-3GPP access

5. Multi-Access (MA) PDU Session
5.1. PDU Session Types in 5GS
5.1.1. PDU session established over 3GPP access
5.1.2. PDU session established over non-3GPP access
5.1.3. PDU session established over 3GPP and non-3GPP accesses : MA PDU Session
5.2. URSP for MA PDU session
5.3. ATSSS (Access Traffic Steering, Switching, Splitting)
5.4. Steering modes
5.5. Steering functionalities
5.5.1. MPTCP : Multi-Path TCP
5.5.2. MPQUIC : Multi-Path QUIC
5.5.3. ATSSS-LL : ATSSS Lower Layer
5.5.4. ATSSS rules
5.5.5. MA PDU Session Establishment procedure

6. WWC : Wireline Wireless Convergence
6.1. WWC Architecture
6.1.1. FN-RG connected to the 5GC
6.1.2. 5G-RG connected to the 5GC
6.2. WWC Identities
6.2.1. PEI
6.2.2. GPRS
6.2.3. SUPI
6.2.4. SUCI
6.3. Procedures
6.3.1. FN-RG Authentication
6.3.2. 5G-RG Authentication
6.3.3. PDU sessions establishment for FN-RG for Internet, IMS and IPTV DNN
6.3.4. PDU Sessions establishment for 5G-RG for Internet, IMS and IPTV DNN
6.3.5. Unicast/Multicast packet transmission for IPTV
6.4. AUN3 and NAUN3 devices behind 5G-RG
6.4.1. AUN3 device authentication
6.4.2. NAUN3 device authentication
6.4.3. PDU session establishment for AUN3
6.4.4. PDU session for NAUN3
6.5. UE behind FN-RG or 5G-RG
6.5.1. UE behind 5G-RG using trusted non-3GPP access to the 5GC
6.5.2. UE behind FN-RG using non- non-3GPP access to the 5GC
6.5.3. UE behind 5G-RG using non- non-3GPP access to the 5GC
6.5.4. UE authentication behind FN-RG or 5G-RG

7. Fixed-mobile convergence scenarios