X50-20071126-001 Cisco SAE Architecture Overview

© 2006 Cisco Systems, Inc. All rights reserved.Presentation_ID 1

SAE/LTE Architecture Overview

Parviz Yegani [email protected]

November 26, 2007

TSG-X PDS Teleconference Meeting

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3GPP Evolution3G Architecture• Support of 2G/2.5G and 3G Access• Handover between GSM and UMTS technologies

3G Extensions:

• HSDPA/HSUPA• IP Multimedia Subsystem (IMS)• Interworking with WLAN (I-WLAN)

Beyond 3G:• Long Term Evolution (LTE)• System Architecture Evolution (SAE)• Adding Mobility towards I-WLAN and non-3GPP air interfaces

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SAE Objectives

SAE has the following major goals:

Interworking of multiple access networks under the same packet-switched core network (EPC) • 3GPP Accesses: E-UTRAN (EPS)• Non 3GPP Accesses: UMB, WiMAX, WiFi, DSL, Cable

Integrate legacy 3GPP and non-3GPP access networks in the same architecture• 3GPP legacy networks: UTRAN, GERAN• Non 3GPP legacy networks: CDMA2000 HRPD/1xRTT,

WiFi

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SAE Design PhilosophySAE focus is on:

Enhancement of Packet Switched technology to cope with rapid growth in IP traffic, i.e., • Higher data rates• Lower latency• PS optimized network

This can be achieved through• Fully IP network• Simplified network architecture• Distributed control

Support various access technologies• Wireless• Wired

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SAE Interfaces & CapabilitiesSAE architecture has the following capabilities/interfaces:

Mobility (intra- & inter-access)• GTP-based mobility (S5, S8a)• IETF-based mobility: PMIP, CMIP, DSMIP (S5, S8b, S2a/b/c)

Policy Control and Charging • PCRF (S7, S7a/b/c, S9, Rx+ interfaces)• PCEF (S7, S7a/b/c, Rx+ interfaces)

Roaming• Specifies various roaming interfaces• Supports seamless roaming with diverse access technologies

System Selection & Discovery

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SAE SpecificationsTS23.401v1.3.0 (as of 10-24-2007)• GTP-based Mobility• Link: http://www.3gpp.org/ftp/Specs/html-info/23401.htm

TS23.402v1.4.0 (as of 10-24-2007)• IETF-based Mobility• Link: http://www.3gpp.org/ftp/Specs/html-info/23402.htm

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Non-Roaming Architecture(TS23.402)

SGi

PCRF

S7

HSS

S2b

Wn*

Operator's IP Services (e.g. IMS, PSS etc.)

Wm*

Wx*

UntrustedNon-3GPP Access

Wa*

HPLMN

Non-3GPP Networks

S6c

Rx+

PDN Gateway(PGW)

ePDG 3GPP AAA Server

S7b

S2a

S7a

Ta*

S7c

S5

S6a

3GPPAccess

ServingGateway(SGW)

TrustedNon-3GPP Access

ePDSN

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Mobility Protocol Agreement

The SAE system shall support IETF based network-based mobility management mechanism (e.g., PMIP) and host-based mobility management mechanism (e.g., MIP) over S2 reference points.

The SAE system shall support IETF based network-based mobility management mechanism (e.g., PMIP) over S5, and S8b reference points.

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Protocols on Different Interfaces

S5 & S8b (IETF based variant)– PMIPv6

S2a– PMIPv6– MIPv4 FA mode

S2b– PMIPv6

S2c– DSMIPv6– FFS: MIPv4 CCoA

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Non-3GPP AccessTrusted non-3GPP IP Access: An IP access network trusted by the 3GPP EPC system such as WiMAX, 3GPP2, etc

• Ta* used for Access Authentication

Untrusted non-3GPP IP access: An IP access network that requires use of IPSec between the UE and the 3GPP network in order to provide adequate security mechanism acceptable to 3GPP network operator.

• Wa* used for Access Authentication• Wm* used for Tunnel Authentication

ePDG: Evolved PDG as specified in TS 23.234 with the following gaps compared to PDG:• ePDG does not terminate the Wi interface• ePDG contains PMIPv6 Proxy Mobile Agent (PMA) functionality for network based mobility on S2b

Other extensions/changes are FFS.

ePDG

S2b

Wn*

Trustednon-3GPP IP Access

(e.g., HRPD)

Untrustednon-3GPP IP Access

(e.g., WiFi)

S2a

Trusted/Untrusted*non-3GPP IP Access

or 3GPP Access

UE

S2c 3GPP AAA Server

Wm*

Ta*

Wa*

PGW

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Non-Roaming Architecture(PMIP-based S5 interface)

SGi

PCRF

S7

S6a

HSS


S1-U

S1-MME

E-UTRAN

2G/3G SGSN

S4

S3

S5 PMIP

Rx+

PDN Gateway(PGW)

MME S11

S10

S7c

Serving Gateway(SGW)

3GPP Access

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Roaming Architecture(w/o Local Breakout)

hPCRF

HSS

HPLMN

Wd*

Non-3GPP Networks

VPLMN

vPCRF

3GPP AAA Proxy

Ta*

3GPP AAA Server

S2a

S7a

S9

SGi

S7

S6c


Rx+Wx*

Wn*

ePDG

Wa*


Wm*

S2b

S7bS7c

S8a/b

S6a

3GPPAccess

ServingGateway (SGW)

Case 1 - non-3GPP anchor (PGW) is in the HPLMN

PDNGateway(PGW)


ePDSN

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Roaming Architecture(w/ Local Breakout)

hPCRF

HSS

HPLMN

Wd*

Non-3GPP Networks

S6d

VPLMN

vPCRF

PDNGateway(PGW)

3GPP AAA Proxy

3GPP AAA Server

S7a

S9

S2a

S7

Rx+

SGi

Wx*

Ta*

Visited network IP services or proxies to home network

services or PDN

Rx+

S7b

ePDGS2b

Wn*

Wm*


Wa*

S5

S7c

S6aOperator's IP Services

(e.g. IMS, PSS etc.)

3GPPAccess

ServingGateway (SGW)

Case 2 - non-3GPP anchor (PGW) is in the VPLMN


ePDSN

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Other Roaming Scenarios(not supported by LTE-HRPD IWK)

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SAE Roaming Architecture(using chained S2a/S2b & S8a/b)

SAE architecture also supports other deployment scenarios such as:• Chained S2a/S2b and S8a/b• Home Routed Traffic via S2c, S8a/b (see next slide)

•SGi•S6a

•HSS

•Operator’s IP Services (e.g. IMS, PSS etc.)

PDNSAE gateway

•S8b

S3

S1_MME

S10

GERAN

UTRANSGSN

MME

S11

ServingSAE gateway

+ local non-3GPP anchorS1_U

UE

“LTE -Uu ”

EUTRAN

S4

•HPLMN

•VPLMN

S2a/b/c

As shown above this is the case when VPLMN has business relationship with non-3GPP networks and SGW is in the VPLMN which includes local non-3GPP Anchor function.

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SAE Roaming Architecture(Home-routed traffic using S8a/b, S2c)

hPCRF

HSS

Wn*



Wa*

HPLMN

Wd*

Non-3GPP Networks

VPLMN

vPCRF

ePDG

Wm*


Ta*

3GPP AAA Server

S2c

S2c

S9

SGiS7

Rx+

S6c

UE

3GPP AAA Proxy

Wx*

S7a

S7b

S7c

S8a/b

S6a

S2c

3GPPAccess

ServingGateway

PDNGateway

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Recommendation

This is an FYI contribution.

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Documents

X50-20071126-001 Cisco SAE Architecture Overview