lte core network
TRANSCRIPT
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All material is Copyright © Informa Telecoms & Media 2001-2010
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
LTE Architecture (high level)
SGW PGW
S11
S5
EPC
All IP
All New
MME S1-MME
S1-U
eNB eNB X2
eUTRAN
eNB – Evolved Node B;MME – Mobility Management Entity; SGW – Serving Gateway
P-GW – Packet Data Gateway UE – User Equipment
UE
5
LTE Architecture (high level)
SGW PGW
S11
S5
EPC
All IP
All New
MME S1-MME
S1-U
eNB eNB X2
eUTRAN
eNB – Evolved Node B;MME – Mobility Management Entity; SGW – Serving Gateway
P-GW – Packet Data Gateway UE – User Equipment
UMTS WLAN
S3,S4,S12 S2
Interworking
Defined interfaces for interworking
UMTS/GPRS interworking
WiFi/WiMAX Interworking
Interworking with Trusted/non-Trusted
UE
6
LTE Architecture (high level)
PGW
S11
S5
EPC
All IP
All New
MME S1-MME
S1-U SGW
eNB eNB X2
eUTRAN
IMS
SGi
eNB – Evolved Node B;MME – Mobility Management Entity; SGW – Serving Gateway
P-GW – Packet Data Gateway UE – User Equipment
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
All material is Copyright © Informa Telecoms & Media 2001-2010
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
All material is Copyright © Informa Telecoms & Media 2001-2010
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