LTE SAE System Overview 1 LTE System Overview LTE SAE System Overview 2

LTE SAE System Overview

LTE System Overview www.huawei.com

Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved.

Contents 1. Network Architecture 2. Air Interface Principles 3. LTE Signaling Procedure

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LTE SAE System Overview

Contents 1 Network Architecture 1.1 Evolution of Cellular Networks 1.2 3GPP Releases 1.3 E-UTRAN Architecture 1.4 E-UTRAN Interfaces and Protocols 1.5 EPC Architecture 1.6 EPC Interfaces and Protocols

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Evolution of Cellular Networks

1G (First Generation)

2G (Second Generation)

3G (Third Generation)

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4G (Fourth Generation)

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LTE SAE System Overview

First Generation Mobile Systems 

AMPS (Advanced Mobile Telephone System)



TACS (Total Access Communications System)



ETACS (Extended Total Access Communications System)

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Second Generation Mobile Systems 2G (Second Generation)

Other

GSM

cdmaOne (IS-95)

D-AMPS (IS-136)

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LTE SAE System Overview

2.5G and 2.75G GSM/GPRS Systems System

Service

Theoretical Data Rate

Typical Data Rate

2G GSM

Circuit Switched Data Service

9.6kbit/s or 14.4kbit/s

9.6kbit/s or 14.4kbit/s

2.5G GPRS

Packet Switched Data

171.2kbit/s

4kbit/s to 50kbit/s

2.75G EDGE

Packet Switched Data

473.6kbit/s

120kbit/s

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Third Generation Mobile Systems

UMTS W-CDMA

3G (Third Generation)

Other

UMTS TD-CDMA

CDMA2000

TD-SCDMA

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LTE SAE System Overview

Fourth Generation Mobile Systems Key IMT Advanced Features A high degree of commonality of functionality worldwide while retaining the flexibility to support a wide range of services and applications in a cost efficient manner. Compatibility of services within IMT and with fixed networks. Capability of interworking with other radio access systems. High quality mobile services. User equipment suitable for worldwide use. User-friendly applications, services and equipment. Worldwide roaming capability. Enhanced peak data rates to support advanced services and applications (100Mbit/s for high and 1Gbit/s for low mobility were identified as targets).

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Fourth Generation Mobile Systems 4G (Fourth Generation)

LTE Advanced

UMB (EV-DO Rev C)

WiMAX 802.16m

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LTE SAE System Overview

Contents 1 Network Architecture 1.1 Evolution of Cellular Networks 1.2 3GPP Releases 1.3 E-UTRAN Architecture 1.4 E-UTRAN Interfaces and Protocols 1.5 EPC Architecture 1.6 EPC Interfaces and Protocols

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3GPP Releases Phase 2+ (Release 97)

Release 99

Release 6

Release 8

GPRS 171.2kbit/s

UMTS 2Mbit/s

HSUPA 5.76Mbit/s

LTE +300Mbit/s

Release 9/10 LTE Advanced

GSM 9.6kbit/s

EDGE 473.6kbit/s

HSDPA 14.4Mbit/s

Phase 1

Release 99

Release 5

HSPA+ 28.8Mbit/s 42Mbit/s Release 7/8

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LTE SAE System Overview

Release 5 - HSDPA HSDPA Adaptive Modulation Flexible Coding Fast Scheduling (2ms) HARQ

UTRAN

Iub Node B

RNC

UE

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Release 6 - HSUPA

HSUPA Flexible Coding Fast Power Scheduling HARQ

UTRAN

Iub Node B

RNC

UE

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LTE SAE System Overview

Release 7 - HSPA+ HSPA+ 64 QAM (DL) 16 QAM (UL) MIMO Operation (DL) Power Enhancements (DL) Less Overhead (DL)

UTRAN

Iub Node B

RNC

UE

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Release 8 - HSPA+ and LTE HSPA+ 64 QAM + MIMO (DL) Dual Cell Operation Less Overhead (UL)

UTRAN

Iub Node B LTE Enhanced Techniques Flexible Bandwidth Flexible Spectrum Options High Data Rates Very Fast Scheduling Improved Latency

RNC

UE

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E-UTRAN

eNB

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LTE SAE System Overview

Release 9 and Beyond

LTE Release 8

LTE Release 9

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LTE Advanced Release 10

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Contents 1 Network Architecture 1.1 Evolution of Cellular Networks 1.2 3GPP Releases 1.3 E-UTRAN Architecture

1.4 E-UTRAN Interfaces and Protocols 1.5 EPC Architecture 1.6 EPC Interfaces and Protocols

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LTE SAE System Overview

E-UTRAN Architecture IMS

HSS

CSCF

Video AS

E-UTRAN

UE

EPC

MME eNB

eNB

S-GW

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PDN-GW

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User Equipment EPS Mobility Management Registration Tracking Area Update Handover

Control Plane

EPS Session Management Bearer Activation Bearer Modification Bearer Deactivation

EPS Mobility & EPS Session Management UE

User Plane

IP Adaptation Function

Radio Resource

Radio Resource RRC, PDCP, RLC, MAC & Phy Layer Protocols

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LTE SAE System Overview

UE Categories UE Category

Maximum Downlink Data Rate

Number of Downlink Data Streams

Maximum Uplink Data Rate

Support for Uplink 64QAM

1

10.3Mbit/s

1

5.2Mbit/s

No

2

51.0Mbit/s

2

25.5Mbit/s

No

3

102.0Mbit/s

2

51.0Mbit/s

No

4

150.8Mbit/s

2

51.0Mbit/s

No

5

302.8Mbit/s

4

75.4Mbit/s

Yes

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UE Identities 

IMSI (International Mobile Subscriber Identity)



IMEI (International Mobile Equipment Identity)



GUTI (Globally Unique Temporary Identity)



S-TMSI (Serving - Temporary Mobile Subscriber Identity)



IP Address - This may either be an IPv4 or IPv6 address

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LTE SAE System Overview

Evolved Node B Packet Classification and QoS Policy Enforcement

Radio Resource Management

Data Compression

eNB Routing

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Data Protection

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eNB Identities 

TAI (Tracking Area Identity) - is a logical group of neighboring cells defined by the service provider in which an LTE idle UE is able to move within without needing to update the network. As such, it is similar to a RAI (Routing Area Identity) used in 2G and 3G packet switched networks.



ECGI (Evolved Cell Global Identity) - is comprised of the MCC, MNC and ECI (Evolved Cell Identity), the later being coded by each service provider.

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LTE SAE System Overview

Contents 1 Network Architecture 1.1 Evolution of Cellular Networks 1.2 3GPP Releases 1.3 E-UTRAN Architecture 1.4 E-UTRAN Interfaces and Protocols 1.5 EPC Architecture 1.6 EPC Interfaces and Protocols

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E-UTRAN Interfaces and Protocols E-UTRAN Uu

EPC S1-MME S1-MME S1-U

eNB

X2

MME

S1-U eNB

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S-GW

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LTE SAE System Overview

Uu Interface Uu UE

eNB

User Plane

Control Plane

IP

RRC

PDCP

PDCP

RLC

RLC

MAC

MAC

PHY

PHY

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X2 Interface X2 eNB

eNB

Control Plane

User Plane

X2AP

GTP-U

SCTP

UDP

IP

IP

Layer 2

Layer 2

Layer 1

Layer 1

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LTE SAE System Overview

S1 Interface S1-U

S1-MME MME

eNB

eNB

S-GW

Control Plane

User Plane

S1AP

GTP-U

SCTP

UDP

IP

IP

Layer 2

Layer 2

Layer 1

Layer 1

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Contents 1 Network Architecture 1.1 Evolution of Cellular Networks 1.2 3GPP Releases 1.3 E-UTRAN Architecture

1.4 E-UTRAN Interfaces and Protocols 1.5 EPC Architecture 1.6 EPC Interfaces and Protocols

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LTE SAE System Overview

EPC Architecture EPC S1-MME

S10 MME MME

S11

S5/S8

S1-U S-GW

SGi PDN-GW

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Mobility Management Entity NAS Signaling and Security

Authentication

S-GW and PDN-GW Selection Inter MME Mobility

MME Tracking Area List Management and Paging

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LTE SAE System Overview

Serving - Gateway GTP/PMIP Support

Mobility Anchor

Downlink Packet Buffering Lawful Interception

S-GW Packet Routing and Forwarding

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Packet Data Network - Gateway Packet Filtering Accounting

Lawful Interception

Transport Level Packet Marking

PDN-GW

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IP Address Allocation

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LTE SAE System Overview

Contents 1 Network Architecture 1.1 Evolution of Cellular Networks 1.2 3GPP Releases 1.3 E-UTRAN Architecture 1.4 E-UTRAN Interfaces and Protocols 1.5 EPC Architecture 1.6 EPC Interfaces and Protocols

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S11 Interface S11 MME

S-GW Control Plane GTPv2-C UDP IP Layer 2 Layer 1

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LTE SAE System Overview

S5/S8 Interface S5/S8 PDN-GW

S-GW Control Plane

User Plane

GTPv2-C

GTP-U / PMIP

UDP

UDP

IP

IP

Layer 2

Layer 2

Layer 1

Layer 1

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S10 Interface S10 MME

MME Control Plane GTPv2-C UDP IP Layer 2 Layer 1

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LTE SAE System Overview

SGi Interface SGi PDN-GW Applications TCP / UDP IP Layer 2 Layer 1

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Additional Network Elements and Interfaces CDMA 2000 S6a EIR

HSS

S13

S101

EPC S10 S3

MME

SGSN

PCRF

MME

S11

Gx

S4 S2a

S5/S8 S-GW

S12

PDN-GW

S103

RNC

Trusted Non 3GPP IP Access

S2b Wn

CDMA 2000

Untrusted Non 3GPP IP Access

ePDG

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LTE SAE System Overview

Contents 1. Network Architecture 2. Air Interface Principles 3. LTE Signaling Procedure

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Contents 2 LTE Air Interface Principles 2.1 Radio Interface Techniques 2.2 Principles of OFDM 2.3 Downlink OFDMA 2.4 Uplink SC-FDMA

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LTE SAE System Overview

Radio Interface Techniques Radio Interface Techniques

OFDMA

FDMA

TDMA

CDMA

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Frequency Division Multiple Access Power

Time FDMA Each user allocated a different subband/ channel.

Frequency

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LTE SAE System Overview

Time Division Multiple Access

Power

Time TDMA Each user allocated a different subband/ channel.

Frequency

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Code Division Multiple Access

Power

Time CDMA Each user allocated a different code on the channel.

Frequency

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LTE SAE System Overview

Orthogonal Frequency Division Multiple Access Power

Time

OFDMA Each user allocated a different resource which can vary in time and frequency.

Frequency

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Transmission Modes Frequency Division Duplex Channel Bandwidth

Channel Bandwidth

Uplink

Downlink

Frequency

Duplex Spacing

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LTE SAE System Overview

Transmission Modes Time Division Duplex Downlink and Uplink

Asymmetric Allocation

Frequency

TDD

Downlink

Uplink

TDD Frame

Downlink

Uplink

Time

TDD Frame

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Contents 2 LTE Air Interface Principles 2.1 Radio Interface Techniques 2.2 Principles of OFDM 2.3 Downlink OFDMA 2.4 Uplink SC-FDMA

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LTE SAE System Overview

Principles of OFDM OFDM (OFDMA)

eNB OFDM (SC-FDMA)

UE

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Frequency Division Multiplexing Guard Band

Subcarrier

Frequency Channel Bandwidth

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LTE SAE System Overview

OFDM Subcarriers Orthogonal Subcarriers

Centre Subcarrier Not Orthogonal

Frequency Channel Bandwidth

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OFDM Symbol Mapping Modulated OFDM Symbol

Time

Amplitude Cyclic Prefix

Frequency OFDM Symbol

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LTE SAE System Overview

Contents 2 LTE Air Interface Principles 2.1 Radio Interface Techniques 2.2 Principles of OFDM 2.3 Downlink OFDMA 2.4 Uplink SC-FDMA

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OFDMA in LTE Frequency Device is allocated one or more PRB (Physical Resource Blocks)

Channel Bandwidth E.g. 3MHz

OFDMA

PRB consists of 12 subcarriers for 0.5ms

Time

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LTE SAE System Overview

Physical Resource Blocks and Resource Elements Radio Frame = 10ms

0

1

2

3

4

5

6

7

8

9

Subframe Slot 8

Slot 9

NRBDL

NSCRB Subcarriers = 12

Physical Resource Block

Resource Element

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Contents 2 LTE Air Interface Principles 2.1 Radio Interface Techniques 2.2 Principles of OFDM 2.3 Downlink OFDMA 2.4 Uplink SC-FDMA

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LTE SAE System Overview

SC-FDMA Signal Generation N symbols sequence produces N subcarriers

DFT Output

First N Symbols DFT Modulated and Coded Symbols Second N Symbols DFT

Different input sequence produces different output

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SC-FDMA and the eNB Time

Second N Symbols IDFT

Power Cyclic Prefix

First N Symbols IDFT

N Subcarriers

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LTE SAE System Overview

Contents 1. Network Architecture 2. Air Interface Principles 3. LTE Signaling Procedure

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UE Initial Attach Procedure eNodeB

MME

UE

Uu:RRC/NAS

S1-MME:S1AP

RA PREEMBLE Random Access

RA RESPONSE RRC_CONN_REQ

RRC Connection

RRC_CONN_SETUP RRC_CONN_SETUP_CMP

S1AP_INITIAL_UE_MSG NAS Procedure

RRC_SECUR_MODE_CMD

E-RAB Setup

S1AP_INITIAL_CONTEXT_SETUP_REQ

RRC_SECUR_MODE_CMP RRC_UE_CAP_ENQUIRY RRC_UE_CAP_INFO RRC_CONN_RECFG RRC_CONN_RECFG_CMP S1AP_INITIAL_CONTEXT_SETUP_RSP NAS Procedure

Dedicated E-RAB Setup

E-RAB_SETUP_REQ

RRC_CONN_RECFG RRC_CONN_RECFG_CMP E-RAB_SETUP_RSP

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LTE SAE System Overview

Typical X2 Handover Flow UE

Source eNB

Target eNB

Serving

MME

Gateway

0.Area Restriction Provided 1.Measurement Control (RRC_CONN_RECFG) packet data

packet data UL allocation

Legend

2.Measurement Reports (RRC_MEAS_RPRT)

L3 signalling L1/L2

3.HO decision

signalling

Handover Preparation

4.Handover Request (HANDOVER_REQUEST)

User Data

5.Admission Control 6.Handover Request Ack (HANDOVER_REQUEST_ACKNOWLEDGE)

DL allocation 7.RRC Conn. Reconf. incl. mobilityControlinformation (RRC_CONN_RECFG(HO_CMD)) Detach from old cell and synchronlze to new cell

Deliver buffered and in transit packets to target eNB

Handover Execution

8.SN Status Transfer (SN_STATUS_TRANSFER) Data Forwarding

9.Synchronisation

Buffer packets from Source eNB

10.UL allocation+TA for UE 11.RRC Conn. Reconf. Complete (RRC_CONN_RECFG_CMP(HO_CMP))

packet data

packet data

End Marker

14.Switch DL path packet data

End Marker 17. UE Context Release (UE_CONTEXT_RELEASE)

16.Path Switch Request Ack (S1AP_PATH_SWITCH_REQ_ACK)

15.User Plane update response

Handover Completion

12.Path Switch Request (S1AP_PATH_SWITCH_REQ) 13.User Plane update request

18.Release Resources Measurement Control (RRC_CONN_RECFG) Measurement Control CMP (RRC_CONN_RECFG_CMP)

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Thank you www.huawei.com

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