Content for TR 23.896 Word version: 12.0.0

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1 Scope p. 7

This Technical Report addresses stage 2 study for the Evolved Packet System (EPS) to facilitate policy and charging control in the fixed broadband access network in the convergent scenario where a single operator is deploying both the fixed broadband access network and the Evolved Packet Core (EPC).

The scope of this TR is to consider the convergent scenario where the PCRF controls directly the network element(s) in the fixed broadband access without the mediation of a different policy server, such as the BPCF defined in TS 23.139.

The work in this TR takes the fixed broadband accesses as specified by BroadBand Forum as a reference. This does not preclude the applicability of the solutions described in this TR to other types of fixed broadband accesses.

This TR will address policy and charging control for:

Traffic to/from fixed devices connected to the fixed broadband access network (e.g. PC, IPTV Set top Box).
Traffic exchanged by 3GPP UEs connected via WLAN or H(e)NB when both the fixed broadband access network and the EPC are under the control of the EPS operator.

The work is organized in the building blocks and this TR address the Building block listed below, for an outline of the content of each building block refers to clause 4:

BB1: Policy and Charging Control for supporting traffic from fixed terminals and NSWO traffic from 3GPP UEs in fixed broadband access networks (P4C-F).
BB3: Policy and Charging Control for 3GPP UEs connected to fixed broadband access network via S2b and S2c reference points for EPC routed traffic (P4C-S2bc).
BB4: Policy and Charging Control for EPC routed traffic over fixed broadband access networks of 3GPP UEs connected via H(e)NB in convergent scenarios (P4C-HeNB).
BB5: Policy and Charging Control for supporting Layer 2 traffic in fixed broadband access network (P4C-FL2).
BB6: Policy and Charging Control for 3GPP UEs connected to fixed broadband forum access networks as Trusted network in Convergence scenario (P4C-TC).

2 References p. 7

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

[1]

TR 21.905: "Vocabulary for 3GPP Specifications".

[2]

TS 23.401: "GPRS Enhancements for E-UTRAN Access".

[3]

TS 23.402: "Architecture enhancements for Non-3GPP Accesses ".

[4]

TS 23.203: "Policy and charging control architecture".

[5]

TS 22.278: "Service requirements for the Evolved Packet System (EPS)".

[6]

Broadband Forum WT-203: "Interworking between Next Generation Fixed and 3GPP Wireless Access" (work in progress).

[7]

Broadband Forum TR-058: "Multi-service Architecture and Framework Requirements" September 2003.

[8]

Broadband Forum TR-101: "Migration to Ethernet-based DSL Aggregation" April 2006.

[9]

Broadband Forum WT-145: "Multi-service Broadband Network Functional Modules and Architecture" work in progress.

[10]

Broadband Forum WT-134: "Policy Control Framework" work in progress.

[11]

TS 29.274: "General Packet Radio Service (GPRS); Evolved GPRS Tunnelling Protocol (eGTP) for EPS".

[12]

BBF TR-092: "Broadband Remote Access Server (BRAS) Requirements".

[13]

BBF TR-124: Issues 2 "Functional Requirements for Broadband RG Devices".

[14]

TS 23.234: "3GPP system to Wireless Local Area Network (WLAN) interworking".

[15]

Broadband Forum WT-146: "Subscriber sessions" work in progress.

[16]

Broadband Forum WT-178: "Multi-service Broadband Network Architecture and Nodal Requirements " work in progress.

[17]

Broadband Forum WT-300: "Converged Policy Management" work in progress.

[18]

Broadband Forum WT-291: "Nodal Requirements for Interworking between Next Generation Fixed and 3GPP Wireless Access" work in progress.

[19]

TS 33.402: "3GPP System Architecture Evolution (SAE); Security aspects of non-3GPP accesses".

[20]

TS 23.139: "3GPP system - fixed broadband access network interworking; Stage 2".

[21]

TS 23.335: "User Data Convergence (UDC); Technical realization and information flows; Stage 2".

[22]

Broadband Forum WT-144: "Broadband Multi-Service Architecture & Framework Requirements".

[23]

TS 32.251: "Telecommunication management; Charging management; Packet Switched (PS) domain charging".

[24]

RFC 4006: "Diameter Credit-Control Application".

[25]

TS 32.240: "Telecommunication management; Charging management; Charging architecture and principles".

[26]

TS 32.296: "Telecommunication management; Charging management; Online Charging System (OCS): Applications and interfaces.

[27]

TR 23.800: "Study on Application Based Charging; Stage 2".

[28]

TR 23.839: "Support for BBF Accesses Interworking".

[29]

TS 23.228: "IP Multimedia Subsystem (IMS); Stage 2".

3 Definitions, symbols and abbreviations p. 9

3.1 Definitions p. 9

For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.

UE local IP address is defined as:

either the public IP address assigned to the UE by the BBF domain in the no-NAT case, or the public IP address assigned by the BBF domain to the NATed RG that is used for this UE.

Non-seamless WLAN offload (NSWO):

is a capability of a UE supporting routing specific IP flows over the WLAN access without traversing the EPC as defined in clause 4.1.5 of TS 23.402.

EPC-routed:

User plane traffic that is routed via a PDN GW in EPC as part of a PDN Connection. EPC-routed applies to non-roaming, roaming with traffic home-routed and roaming with traffic local break-out cases.

3.2 Abbreviations p. 9

For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.

ANDSF

Access Network Discovery and Selection Function

BBF

Broadband Forum

BRAS

Broadband Remote Access Server

BNG

Broadband Network Gateway

BPCF

Broadband Policy Control Function

DSMIPv6

Dual-Stack MIPv6

EPC

Evolved Packet Core

ePDG

Evolved Packet Data Gateway

EPS

Evolved Packet System

H-ANDSF

Home-ANDSF

MME

Mobility Management Entity

NSWO

Non-Seamless Wireless Offload

P-GW

PDN Gateway

PMIP/PMIPv6

Proxy Mobile IP version 6

Residential Gateway

S-GW

Serving GW

V-ANDSF

Visited-ANDSF

4 Building blocks p. 9

The architecture study for convergence scenario is planned to be performed within five Building Blocks, with the scope for each BB described in the following.

4.1 Building Block 1 PCC for supporting traffic from fixed terminals and NSWO traffic from 3GPP UEs p. 9

This BB will focus on policy and charging control for:

Traffic to/from fixed devices.
NSWO traffic exchanged by 3GPP UEs connected to the fixed broadband access via WLAN.

Specific objectives of this BB are to study and define:

The reference architecture for policy and charging control in the convergent scenario.
Any required enhancements for 3GPP PCC to provide policies for IP traffic exchanged by fixed devices in the fixed broadband access.
Any required enhancements to 3GPP PCC to provide policies NSWO traffic exchanged by 3GPP UEs connected to the fixed broadband access via WLAN.
Architecture and requirements to provide charging for traffic exchanged by fixed devices and NSWO traffic to/from 3GPP UEs in the following scenarios:
- 3GPP PCC- Gy/Gz based charging with PCEF located in the fixed broadband access network;
- Traffic Detection Function (TDF)-based charging;
- AAA-based charging as already specified for interworking scenario.
NOTE 2:
All the above solutions will be studied and standardized as alternative solutions for providing charging.
The subscription information for fixed devices (e.g. identifiers, maximum subscribed bit rate, etc.) required for policy and charging control.
The usage of the SPR or UDR to store policy related subscription information for fixed devices.

In this BB only policy and charging control for IP sessions will be considered, while policy control and charging for Layer 2 VPNs will be considered in P4C-FL2.

Policy control will address both dynamic and pre-provisioned policies in the BNG.

4.2 Building Block 3 PCC for 3GPP UE connected to fixed broadband access networks via S2b and S2c reference points for EPC routed traffic p. 10

This Building Block will focus to provide stage 2 specifications for converged policy management and charging for the convergent scenarios with traffic routed to EPC for operators providing both 3GPP and fixed broadband access network for following scenarios:

WLAN S2b: UE connects to WLAN/BBF with traffic routed to ePDG/PDN GW.
WLAN S2c (trusted): UE connects to WLAN/BBF with traffic routed to PDN GW via s2c.
WLAN S2c (untrusted): UE connects to WLAN/BBF with traffic routed to PDN GW through ePDG via S2c.

This BB will study and define any possible enhancement of 3GPP PCC for supporting policy management for the resource allocation and the QoS enforcement at the BBF access network for a 3GPP UE.

The traffic is EPC routed so accounting and charging is performed in 3GPP EPC network.

The solution defined in BB 3 shall be compatible with the solution defined in BB 1 (P4C-F) to ensure the consistent policy enforcement for the 3GPP UE connecting to the EPC via S2b or S2c with the consideration that the NSWO may have been be activated for the same UE as specified in BB 1.

4.3 Building Block 4 PCC for EPC routed traffic over fixed broadband access networks of 3GPP UEs connected via H(e)NB p. 11

This Building Block will focus to provide stage 2 specifications for converged policy management and charging for the scenarios with traffic routed to EPC for operators providing both 3GPP and BBF accesses for the following scenario:

3GPP UE connects to a H(e)NB, which is connected to the EPC via a fixed broadband access network.

This BB will study and define any possible enhancement of 3GPP PCC for supporting policy management for the resource allocation and the QoS enforcement in the BBF access network for a 3GPP UE connected to a H(e)NB.

The traffic is EPC routed so accounting and charging is performed in 3GPP EPC network.

4.4 Building Block 5 PCC for supporting Layer 2 traffic in fixed broadband access networks p. 11

This Building Block will focus to provide stage 2 specifications to enhance 3GPP PCC for supporting policy and charging control in fixed broadband access in the convergent scenario when single operator is deploying both fixed broadband access and the Evolved Packet Core (EPC).

The scope is to support dynamic QoS for fixed access session associated with layer 2 based sessions(, i.e. session identified by layer 2 identity, e.g. VLAN Tag)

Specific objectives of this BB are to study and define:

Enhancements of the reference architecture, if needed, for policy and charging control in the convergent scenario.
Any required enhancements to 3GPP PCC to provide policies for L2 traffic exchanged in the fixed broadband access.
Enhancements of solutions to support AAA-based accounting for traffic exchanged by fixed devices. The support of 3GPP PCC charging is not considered in this release within the scope of this BB.

The activities performed under this BB will consider the result of other BBs that are part of the P4C features if needed.

4.5 Building Block 6 PCC for 3GPP UE connected to fixed broadband access networks via S2a reference point for EPC routed traffic p. 11

This BB will consider the architecture defined in TS 23.402, clause 16. Both GTP and PMIP protocol variants for S2a will be considered.

This BB will study and define any possible enhancement of 3GPP PCC for supporting policy management for the resource allocation and the QoS enforcement for a 3GPP UE.

The work in this BB will be carried out taking the fixed broadband accesses as specified by BroadBand Forum as a reference. This BB will identify additional deployment scenarios. However, the architecture will be designed in a way to be also applicable to these deployment scenarios.

The traffic is EPC routed so accounting and charging is performed in 3GPP EPC network.

The solution defined in BB 4 shall be compatible with the solution defined in BB 4 (P4C-F) to ensure the consistent policy enforcement for the 3GPP UE connecting to the EPC via S2a with the consideration that the NSWO may have been be activated for the same UE as specified in BB 4.

As S2a traffic is EPC routed, charging is performed in 3GPP EPC. The support of accounting by the TWAN is out of scope of this WID.

The charging aspects for EPC access via TWAN are thus about to define:

whether any user charging related information is missing that needs to be transferred to PDN GW/OCS/OFCS;
a solution to provide the EPC (i.e. PDN GW) with the necessary user charging related information.