lte network: how it all comes together architecture technical poster

VISITED NETWORK HOME NETWORK

LTE Express: End-to-End LTE NetworkTIME TO GET ON BOARD – THE ULTRA-BROADBAND EXPERIENCE CUSTOMERS EXPECT

STANDARDIZED LTE FREQUENCY BANDS GLOBAL VIEW: LTE ACCESS AND EPC NETWORK

PROTOCOLS AND SECURITY LTE AND EPC – MOBILITY AND ROAMING

VOICE OVER LTE WITH ENHANCED SINGLE RADIO VOICE CALL CONTINUITY

LTE EPS BEARER QoS LEVELS

NON-3GPP INTERWORKING – DATA SERVICES

LEGACY 3GPP INTERWORKING – DATA SERVICES

LEGACY 3GPP INTERWORKING – VOICE SERVICES

FDD Band

1

2

3

4

5

7

8

9

10

11

12

13

14

17

18

19

20

21

22

23

24

25

26

27

28

291

30

31

Common name

IMT core (FDD)

US PCS

DCS

AWS-1

850 Cellular

IMT-E

E-GSM

UMTS 1700 Japan DCS

E-AWS (AWS-3)

Lower PDC (Japan)

NAR L700 (A/B/C)

NAR U700 ( C)

Upper 700 ( D - US Public Safety)

Lower 700 (B/C)

Japan Lower 800

Japan Upper 800

EU Digital Dividend

Upper PDC (Japan)

3.5 GHz FDD

S-Band (AWS-4)

L-Band

US Extended PCS

Extended Cellular

SMR

APT700 Digital Dividend

Lower SMH Blocks D/E

WCS Blocks A/B

450 Brazil

Frequencies (MHz – UL / DL)

1920-1980 / 2110-2170

1850-1910 / 1930-1990

1710-1785 / 1805-1880

1710-1755 / 2110-2155

824-849 / 869-894

2500-2570 / 2620-2690

880-915 / 925-960

1749.9-1784.9 / 1844.9-1879.9

1710-1770 / 2110-2170

1427.9-1447.9 / 1475.9-1495.9

699-716 / 729-746

777-787 / 746-756

788-798 / 758-768

704-716 / 734-746

815-830 / 860-875

830-845 / 875-890

832-862 / 791-821

1447.9-1462.9 / 1495.9-1510.9

3410-3490 / 3510-3590

2000-2020 / 2180-2200

1626.5-1660.5 / 1525-1559

1850-1915 / 1930-1995

814-849 / 859- 894

807-824 / 852-869

703-748 / 758-803

N/A / 717-728

2305-2315 / 2350-2360

452.5-457.5 / 462.5-467.5

TDD Band

33

34

35

36

37

38

39

40

41

42

43

44

RADIO LAYER AND FEATURES

• PHY (Physical layer): Radio transmission based on high performance OFDM (Orthogonal Frequency Division Multiplex) and MIMO (Multiple In/Multiple Out) techniques

• MAC (Media Access Control): Schedules radio transmissions, provides HARQ (Hybrid ARQ) error handling, selects MCS (Modulation and Coding Scheme) and handles Carrier Aggregation (CA) process

• RLC (Radio Link Control): Maps radio bearers and provide ARQ (Automatic Retransmission reQuest) error handling

• PDCP (Packet Data Convergence Protocol): Maps radio bearers and provides user and control plane ciphering using AES and Snow algorithms

• RRC (Radio Resource Control): Controls radio layers and access

• NAS (Non-Access Stratum): Provides secure signalling link between UE and MME to carry EPS (Evolved Packet System) Mobility Management (EMM) and EPS Session Management (ESM) messages

EVOLVED PACKET CORE (EPC)

• SGW and PGW: Extended to support interface from SGW in visited network to PGW located in home network (S8), SGW provides charging information and legal interception for visited network

• PCRF: Extended to interface between visited and home networks (S9)

• MME and PCRF: Enhanced to enforce roaming related policies

IP CORE NETWORK

• IPX: IP Packet exchange: Set of networking functionality offering user plane and control plane

END USER SERVICE

• IP access offered using both home and/or visited network routed services

NETWORK PROTOCOLS AND FEATURES

• GTP (GPRS Tunnel Protocol): Controls establishment of interfaces (GTP-C) and transport of user plane EPS bearers (GTP-U) between network elements

• S1AP (S1 interface Application Part): Controls establishment and management of eNB-MME interface

• Diam(eter): Internet protocol used to carry Authentication, Authorization and Accounting (AAA) messages

• AKA (Authentication and Key Agreement (AKA): Used to securely carry key management messages between SIM, MME and HSS

• IPsec (IP Security protocol): Secure transport tunnel for IP transmission from eNB to SeGW (Security Gateway)

USER EQUIPMENT

• UE (User equipment): Terminates LTE radio interface and provides IP transport for end-user traf�c

• SIM (Subscriber Information Module): Provides authentication of securely stored subscriber information and negotiates encryption keys for session protection

RADIO ACCESS NETWORK

• eNB (evolved Node B): Provides LTE access including radio layer encryption, terminates network interfaces, maps EPC bearers into LTE radio access bearers, responsible for MME selection and forwarding of Non-Access Stratum (NAS) signalling, controls mobility between eNBs, includes MBMS Control Element (MCE) function.

MULTIMEDIA BROADCAST AND MULTICAST

• BM-SC (Broadcast and Multicast Service Centre): Acts as gateway between Application Server providing broadcast content and MBMS-GW (SGmb for control and SGi-mb for user plane), provides UE MBMS reception error handling

• MBMS-GW (Multimedia Broadcast and Multicast Service Gateway): Provides IP source of multicast �ow to eNBs (M1) and forwards service requests from BM-SC to MME (Sm)

CHARGING

• OCS (Online Charging System): Performs online credit control functions for pre-paid and data capped post-paid subscribers

• OFCS (Of�ine Charging System): Collects charging records for post-paid subscribers

END USER SERVICE

• IP address assignment is provided to the UE by the PGW based upon the Access Point Name (APN) of the service.

• Services offered using a default bearer, typically used for best effort Internet access APN or SIP signalling for VoLTE services using IMS APN, which may be supplemented with one or more “dedicated bearers” based on request from application server using SDP (Session Description Protocol) formatted messages


• PGW (PDN Gateway): Acts as end-user IP layer �rst hop router and IP anchor for a given Packet Data Network (PDN) and maps IP �ows into EPC bearers, assigns end-user IP address. Provides charging information, QoS with Policy Enforcement, and legal interception

• SGW (Serving Gateway): Provides traf�c routing through GTP tunnels between one or more PGW (S5) and eNB (S1-u), detects incoming end-user traf�c for idle UEs and noti�es MME

• MME (Mobility Management Entity): Manages UE authentication, LTE RAN connection (S1-MME), mobility

Note 1: Restricted to LTE operation when carrier aggregation is con�gured

Reference: 3GPP 36.101

Main or most commonly used bands are highlighted in Bold

Common name

Core IMT-TDD

Core IMT-unpaired

PCS (uplink)

PCS (downlink)

PCS (duplex gap)

IMT-E TDD

TDD 1900

TDD 2300

BRS/EBC

TDD 3500

TDD 3700

APT 700 Digital Dividend

Frequencies ( MHz )

1900 - 1920

2010 - 2025

1850 - 1910

1930 - 1990

1910 - 1930

2570 - 2620

1880 - 1920

2300 - 2400

2496 - 2690

3400 - 3600

3600 - 3800

703 - 803

AKA AKA AKA

NAS

IP IP

NAS

S1APS1AP Diam. Diam.RRCRRC

PDCP GTP

UDP

IP

GTP

UDP

IP

GTP GTP

IPsec IPsec

MME HSS VISITED NETWORK HOME NETWORK

PGWSGWSeGWeNBUE

UE

HSS

PCRF

BM-SCMBMS-GW

eNB

eNB

MME

PGW

OCS

IP NetworkIP

Mobile core

S1-MME, M3

X2

S1-u

Sm

M1

S5

S5

S11 Gx

Sp

S10

S6a Rx

SGi

SGi

Gy

Gz

Sy

SGmb, SGi-mb

END USER SERVICE

• LTE services are provided using a default and optionally one or more dedicated EPS (Evolved Packet System) bearers per connected APN

END USER SERVICE

• EPC service continuity when using non-3GPP access (CDMA or WLAN)


• PGW: Acts as IP anchor point between LTE and “non-3GPP” access such as CDMA EV-DO and Wi-Fi. Supports “trusted” access over S2a to HSGW (HRPD Serving GW) and/or TWAG (Trusted WLAN Access GW) and “untrusted” access over S2b to ePDG (evolved Packet Data GW)

• 3GPP AAA: Authentication, Authorization and Accounting. Authenticates the UE over non-3GPP access. Acts as gateway between AAA processes over STa/SWa/SWm and SWx interfaces

LEGACY RAN

• Legacy RAN enhanced to support mobility between access technologies

END USER SERVICE

• Legacy SMS delivery and trigger for Circuit Switched Fallback (CSFB) mechanism for legacy voice services


• MME: Supports paging and SMS transfer interface from MSC (SGs) to LTE access

• HSS: Supports legacy interface to MSC (C and D)

LEGACY RAN AND CIRCUIT-SWITCHED (CS) CORE

• MSC: Legacy visited MSC enhanced to support new SGs interface

• RAN: Legacy RAN enhanced to support rapid return to LTE access after voice call

• Each bearer has a corresponding QoS (Quality of Service) level de�ned in terms of QCI (QoS Class Identi�er), Maximum Bit Rate (MBR), optionally a Guaranteed Bit Rate (GBR) and a TFT (Traf�c Flow Template) to map end-to-end IP �ows onto EPS bearers

QCI Type Priority Delay Loss rate Example usage

1 GBR 2 100 ms 10-2 Voice

2 4 150 ms 10-3 Live video (conversational or streaming)

3 3 50 ms 10-3 Gaming

4 5 300 ms 10-6 Buffered streaming video

5 Non-GBR 1 100 ms 10-6 IMS Signalling (default bearer for IMS APN)

6 6 300 ms 10-6 High priority buffered streaming video, TCP, etc.

7 7 100 ms 10-3 Medium priority voice, video, gaming

8 8 300 ms 10-6 High priority best effort Internet

9 9 300 ms 10-6 Best effort Internet (default bearer for Internet)

IP MULTI-MEDIA SUBSYSTEM (IMS)

• CSCF (Call Session Control Function): Proxy, Interrogation and Serving CSCF treat and forward SIP (Session Initiation Protocol) messages

• TAS (Telephony Application Server): Provides Voice over LTE (VoLTE) call logic and services

• MGCF (Media Gateway Control Function) and MGW (Media Gateway): Provides interworking towards legacy voice networks. Combined with Border Gateway Control & Function, it also provides interworking towards VoIP networks

• MRF (Media Resource Function): Provides special media resources (conference bridge, announcements, etc.)

• ATCF (Access Transfer Control Function) and ATGW (Access Transfer Gateway): Support enhanced Single Radio Voice Call Continuity (eSRVCC) mechanism from visited network

• SCC-AS (Service Centralization and Continuity AS): Support eSRVCC mechanism in home network

END USER SERVICE

• Voice over IP using IMS including voice call continuity and roaming

USER EQUIPMENT

• VoLTE client and CS functionsenhanced for SRVCC

LEGACY CIRCUIT SWITCH (CS) CORE

• Legacy MSC enhanced to support SRVCC mechanism


• PGW: Delivers VoLTE bearer with QoS and charging

• MME: Supports SRVCC trigger to MSC (Sv)

• HSS: Supports IMS subscriber data

END USER SERVICE

• EPC service continuity when using legacy 3GPP access


• PGW (acting as legacy GGSN): Acts as mobility anchor point between LTE and legacy 2/3G access such as GSM/GPRS, WCDMA and TD-SCDMA using interface between PGW and SGSN (Gn-u)

• MME: Supports legacy interface to SGSN (Gn-c)

• HSS: Supports legacy interface to SGSN (Gr)

eNodeB

• eNB enhanced to support mobility between access technologies.

LEGACY RAN

• Legacy RAN enhanced to support mobility between access technologies

eNB

eNB

eNB

eNB

NB RNC

BTS BSC

Gz

Gz/Gy

S6a

S9

Rx

Sv Mw

Mw Mw

Cx

Sh

Sh

Mr

Mn

Mg

ISC

SWx

Abis

lub

NB RNC

MSC MSC

BTS BSCAbis A

E

D

CSGs

lub

lups Gn-u

GrGn-c

Gb

S5

S2a

STa/SWm/SWa

S2a

S2b

ISC

Gm

S8

MME PCRF

PGW

PGW

PCRF

HSS

SGW SGW

SGW

SGW

MME

MME

MME

SGSN

3GPP AAAHSS

HSS

HSS

PGWHSGW

TWAG

ePDG

MSC MSC

MME

PCRF

P-CSCF

I-CSCF S-CSCF

SCC-AS

PGW

ATCF

MRF

MGW

TASHSS

MGCFATGW

SGWIP

Mobile core

IPMobile

core

IP NetworkPSTN/VoIP

Applicationserver

App

App

2/3GRAN

SIM

Note: 3GPP Rel-8 interfaces and interworking not shown

References: 3GPP 23.401 and 23.060



References: 3GPP 23.401, 23.203 and 36.300 References: 3GPP 23.228, 23.216 and 23.401 and GSMA IR.92

References: 3GPP 36.300 and 23.401

PGW

References: 3GPP 23.402 and 33.402, IEEE 802.11, 3GPP2 C.S0024References: 3GPP 23.401, 23.246 and 36.300

IPX

IPX

IPX

IPX

IPX

IPX

IPX

UESIM

UESIM

and bearer establishment. Selects PGW(s) and SGW. Manages MBMS service and legal intercept on control signalling

• PCRF (Policy and Charging Rules Function): Provides QoS and Charging policies to the PGW (possibly transformed by PGW into operations on EPC bearers). Policies obtained from various sources including SPR (HSS) and service requirements from Application server

• HSS (Home Subscriber Server): Central database for subscriber data and user service pro�le, performing user and network access authentication and mobility management functions.

UESIMUE

SIM

eNB

eNB

eNB

OFCS

SGW

SIM

AKA

www.alcatel-lucent.com Alcatel, Lucent, Alcatel-Lucent and the Alcatel-Lucent logo are trademarks of Alcatel-Lucent. All other trademarks are the property of their respective owners. The information presented is subject to change without notice. Alcatel-Lucent assumes no responsibility for inaccuracies contained herein. © 2014 Alcatel-Lucent. All rights reserved. NP2014014097 (01)

UESIM

CDMA EV-DOaccess

TrustedWLAN access

UntrustedWLAN access

UDP

IP

UDP

IP

PDCP

RLC

MAC

PHY

RLC

MAC

PHY

26859_LTE_poster_HR.pdf 1 2014-06-03 11:50 AM

lte network: how it all comes together architecture technical poster

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