S.7 PCC Procedures and Flows

23.2033GPPPolicy and charging control architectureRelease 17TS

S.7.1 Introduction

A "Fixed Broadband Access IP-CAN" is a fixed access broadband network that provides IP connectivity to a UE. The Fixed Broadband Access IP-CAN reuses the definition of an IP-CAN session in this specification.

The AF can provide the NATed IP address and ports used by the UE (for IMS, according to TS 23.228 [39]).

NOTE: When the above condition is not met, there are no standardized means as for now to identify a UE behind a NATed-RG.

The Fixed Broadband Access network does not support the concept of a bearer and multiple bearers as defined in TS 23.401 [17]. However, DSCP marking provides QoS support on transport network layer so that QoS and charging policies can be applied per SDF.

Case 1, no Gateway Control Session applies for Fixed Broadband Access.

The procedures cover both non-roaming and roaming with access to NSWO APN for a 3GPP UE. For the roaming case with access to NSWO APN, the V PCRF interacts with the IP-Edge PCEF and, if Sd applies, with the TDF.

S.7.2 IP-CAN Session Establishment

The PCEF located in the IP-Edge initiates the Gx IP‑CAN Session establishment as defined in clause 7.2. The session is initiated after that the IP-Edge becomes aware of an IPv4 address and/or an IPv6 prefix has been assigned to the fixed device and/or 3GPP UE.

In route mode configuration with NATed RG, the session is initiated after the RG has been connected to the network and has been assigned an IPv4 address and/or IPv6 Prefix. The IPv4 address and/or IPv6 Prefix are assigned as per Broadband Forum specifications and it is out of scope of 3GPP.

In bridge mode, the session is initiated after the device has been authenticated has been assigned an IPv4 address and/or IPv6 address or IPv6 Prefix by the Fixed Broadband access.

Operator policies in the PCEF indicate if dynamic policy control is provided. In addition, the NSWO-APN is also configured for subscribers on a PLMN basis.

The PCEF located in the IP-Edge includes in the IP‑CAN Session establishment message the Subscriber-Id, NSWO-APN if available, IP-CAN type, the Default QoS if available, the PLMN id if available and the location information as defined in S.

The IP-Edge maps the Default-Access-Profile QoS to Default-QoS as defined in clause S.5.5.1.

The PCRF may provision a Default QoS or a Default QoS profile, PCC Rules to activate and Events Triggers to report.

S.7.3 IP-CAN Session Termination

This procedure is in accordance with clause 7.3.2 with the exceptions listed in this Annex. The UE-initiated IP-CAN session termination is not to applicable to Fixed Broadband Access.

The IP-CAN session termination is triggered by PCEF when Subscriber IP session is terminated. The trigger to terminate the Subscriber IP session may be HSS/AAA request to detach the UE or may be Broadband Forum specific (e.g. RG switch off, loss of transmission, IP address lease expiration PPPoE session termination, etc) and out of the scope of 3GPP.

In routed mode configuration with NAT this procedure is applicable only when IP session from RG is terminated, e.g. when RG switches off or when public IP address assigned to the RG is released, etc.

NOTE: In routed mode with NAT, the termination of connection from a device in LAN, e.g. when device releases the local IP address or it disconnects from WLAN does not trigger the IP-CAN session termination for IP session from RG.

S.7.4 IP-CAN Session Modification

S.7.4.1 PCEF-Initiated IP-CAN Session Modification

This clause is related to IP-CAN session modification initiated by IP-Edge/PCEF for IP session. This procedure is in accordance with clause 7.4.1 with the exceptions listed in this Annex.

In routed mode with NAT, this procedure can be triggered when new device connects to the RG, for example when UE requests a local IP address to the RG or when a UE disconnects from WLAN.

The IP-Edge reports that an Event was met, including the Event Trigger and the affected PCC Rule. If TDF applies, the PCRF may provide ADC Rules and Event Triggers to the TDF and may provide PCC Rule, Event Triggers and a Default QoS or a Default QoS profile to PCEF.

S.7.4.2 PCRF-Initiated IP-CAN Session Modification

This procedure is in accordance with clause 7.4.2 with the exceptions listed in this Annex.

The PCRF may also provide a Default QoS or a Default QoS profile to PCEF.

S.7.5 Update of the subscription information in the PCRF

This procedure is in accordance with clause 7.5.when the UE’s (i.e. RG, fixed device or 3GPP UE) profile changes.

S.7.6 PCRF Discovery and selection

PCRF discovery and selection follows the principles defined in clause 7.6 with the following modification:

– The Subscriber ID specified in clause S.5.1.2 is used as user identity.

– For a 3GPP UE, the NSWO-APN is also available.

– The IPv6 address may be included in the IP-CAN session establishment in the case of bridge-mode RG.