LTE Core Network

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LTE Core Network

2

EPC

Overall LTE Architecture

S1

SGi

S2

S3, S4

3

LTE Architecture (high level)

eNB eNB X2

eUTRAN

eNB – Evolved Node B;MME – Mobility Management Entity; SGW – Serving Gateway

P-GW – Packet Data Gateway UE – User Equipment

New Access Network Base Station - Evolved Node B

X2 interface for improved Handover and Interference Management

Backhaul Connections are Critical, Capacity

Downlink Radio Interface Orthogonal Frequency Division Multiple Access (OFDMA)

Improved Performance in Urban Areas

Multiple In Multiple Out (MIMO)

Uplink Radio Interface Single Carrier Frequency Division Multiple Access (SC-FDMA)

Good Urban Area Performance

Designed for Good Battery Life

UE

4

New Core Network • Evolved Packet Core

• All IP for efficiency

• New Network Elements

• Designed to be Flexible and

Scalable

• Self Organising Network (SON)

MME • The Control Plane of the network

• Provides Admission Control and

Mobility functions

PGW and SGW • The User Plane of the Network

• Manages the flow of User Data

and application signalling


SGW PGW

S11

S5

EPC

All IP

All New

MME S1-MME

S1-U

eNB eNB X2

eUTRAN



UE

5


SGW PGW

S11

S5

EPC

All IP

All New

MME S1-MME

S1-U

eNB eNB X2

eUTRAN



UMTS WLAN

S3,S4,S12 S2

Interworking

Defined interfaces for interworking

UMTS/GPRS interworking

WiFi/WiMAX Interworking

Interworking with Trusted/non-Trusted

UE

6


PGW

S11

S5

EPC

All IP

All New

MME S1-MME

S1-U SGW

eNB eNB X2

eUTRAN

IMS

SGi



UMTS WLAN

S3,S4,S12 S2 SGs

Connection to External Networks IMS, MMS, WAP, Media Centers

UE

7

S1 Flex - RAN Sharing

EPC - A

EPC - B


EPS Node Functions in Detail

9

MME Functions

MME

• NAS signalling

• Inter CN node signalling for

mobility between 3GPP

access networks

• UE Reachability in ECM-

IDLE state Tracking Area

list management

• PDN GW and Serving GW

selection

• MME selection for

handovers with MME

change

• SGSN selection

• Authentication

• Bearer management

functions including

dedicated

bearer establishment

• Lawful Interception of

signalling traffic

10

SGW Functions

SGW

• Local Mobility Anchor point

for inter-eNodeB handover

• Assist the eNodeB

reordering function during

inter-eNodeB handover

• Mobility anchoring for inter-

3GPP mobility

• ECM-IDLE mode downlink

packet buffering

• Initiation of network

triggered service request

procedure

• Lawful Interception point in

the network

• Packet routing and

forwarding

• Transport level packet

marking in the uplink and

the downlink

11

PGW Functions

PGW

• Packet filtering, via deep

packet inspection

• Allocation of UE IP

addresses

• Downlink packet marking

• Service level charging,

gating and rate

enforcement

• Mobility anchor 3GPP and

non-3GPP

• Terminates the SGi

interface towards the PDN


LTE Services and Bearers

13

Services for LTE

LTE Services • 3rd Party Content

• Operator Managed Content

• Video, Social Networking, WWW

Content Management • IMS

• Service Delivery Platform

• LTE compatible with existing solutions

LTE Network • Is a transport/delivery network

• Can manage content QoS

• High capacity means many customers

14

QoS Class Identifier Values

EPS Bearer Properties

15

Policy Control

PEP

Application

PDP

Application Function

Responsible for offering applications that require the

control per session flow.

It can forward to PDP setup information for taking

decision and applying policy rules in any stage of

session flow.

Policy Decision Point

Responsible for primarily making policy decision per session

or flow basis. It authorizes QoS resources for each flow using

the setup information received via Application Server or PEP.

It can use of additional mechanisms and protocols to achieve

additional functionality such as user authentication,

accounting, policy information

storage, etc.

Policy Enforcement Point

Responsible for applying the policy rules from PDP, enforcing

per session or flow basis the current allowed traffic contract. It

receives a notification or a message that requires a policy

decision.

The PEP then formulates a request for a policy decision and

sends it to the PDP. The PDP returns the Policy decision and

the PEP then enforces the policy decision by accepting or

denying the request.

16

Policy and Charging Rules Function

PCRF

Gx

Predefined rules

• Provisioned in the PCEF

• Referenced by the PCRF

Dynamic rules

• Provisioned by the PCRF

• Provides PCC rule

information to the PCEF

Billing

LTE Core Network

Technology

Transcript of LTE Core Network