Voice over New Radio

This chapter covers the following topics:

Feature Summary and Revision History

Summary Data

Table 1. Summary Data

Applicable Product(s) or Functional Area

5G-UPF

Applicable Platform(s)

VPC-SI

SMI

Feature Default Setting

Enabled – Always-on

Related Changes in this Release

Not Applicable

Related Documentation

Not Applicable

Revision History

Table 2. Revision History
Revision Details Release

First Introduced.

2020.02.0

Feature Description

The UPF supports Voice over New Radio (VoNR) with the existing Session Establishment and Modification procedures. In these procedures, the SMF creates the PDR for 5QI=5 Non-GBR flow for IMS signaling and PDR for 5QI=1 GBR flow for voice traffic. The UPF does not require any special handling to support mobile-originated or mobile-terminated call flows.

How it Works

The following are the steps in the call flow in which the PDRs are created with 5QI value 5 for IMS signaling and 5QI value 1 or Voice Traffic.

VoNR Call Flow for UPF

This section describes the steps for VoNR session and respective PDR Creation on UPF.
Figure 1. VoNR Call Flow
Table 3. VoNR Call Flow
Step Description

1

UE1 and UE2 are registered on 5G network. They establish the IMS PDU session and both are registered with same IMS. Both UEs are in connected mode.

2

For IMS signaling, a non-GBR QoS PDRs (UL and DL) is created by SMF which has the QFI value that corresponds to 5QI value 5.

3

Similarly, for Conversational Voice traffic, the PDRs for GBR QoS flow is created with the QFI value that corresponds to 5QI value 1.

4

The QFI to 5QI mapping is maintained by SMF, hence the QFI does not have the values same as 5QI.

5

The above steps are valid for both Mobile Originated (MO) or Mobile Terminate (MT) call flows.

6

Refer to 3GPP TS 23.501, Section 5.7.4 for other types of 5QI mappings for GBR or Non-GBR flows.