4. LTE Architecture (high level)
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
eNB
X2
eUTRAN
3
eNB – Evolved Node B;MME – Mobility Management Entity; SGW – Serving Gateway
P-GW – Packet Data Gateway UE – User Equipment
eNB
UE
5. LTE Architecture (high level)
New Core Network
• Evolved Packet Core
• All IP for efficiency
• New Network Elements
• Designed to be Flexible and
Scalable
• Self Organising Network (SON)
PGW
MME
PGW and SGW
• The Control Plane of the network
• Provides Admission Control and
Mobility functions
S5
SGW
• The User Plane of the Network
• Manages the flow of User Data
and application signalling
S1-U
eNB
S11
EPC
All IP
All New
4
X2
eUTRAN
MME
S1-MME
eNB – Evolved Node B;MME – Mobility Management Entity; SGW – Serving Gateway
P-GW – Packet Data Gateway UE – User Equipment
eNB
UE
6. LTE Architecture (high level)
Interworking
Defined interfaces for interworking
UMTS/GPRS interworking
WiFi/WiMAX Interworking
Interworking with Trusted/non-Trusted
WLAN
S2
PGW
UMTS
S3,S4,S12
S5
SGW
S1-U
eNB
S11
EPC
All IP
All New
5
X2
eUTRAN
MME
S1-MME
eNB – Evolved Node B;MME – Mobility Management Entity; SGW – Serving Gateway
P-GW – Packet Data Gateway UE – User Equipment
eNB
UE
7. LTE Architecture (high level)
Connection to External Networks
IMS, MMS, WAP, Media Centers
IMS
WLAN
SGi
SGs
S2
PGW
S5
SGW
UMTS
S3,S4,S12
S1-U
eNB
S11
EPC
All IP
All New
6
X2
eUTRAN
MME
S1-MME
eNB – Evolved Node B;MME – Mobility Management Entity; SGW – Serving Gateway
P-GW – Packet Data Gateway UE – User Equipment
eNB
UE
10. MME Functions
•
NAS signalling
•
Inter CN node signalling for
mobility between 3GPP
access networks
•
UE Reachability in ECMIDLE 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
MME
9
11. SGW Functions
•
•
Mobility anchoring for inter3GPP mobility
•
ECM-IDLE mode downlink
packet buffering
•
Initiation of network
triggered service request
procedure
•
Lawful Interception point in
the network
•
Packet routing and
forwarding
•
10
Assist the eNodeB
reordering function during
inter-eNodeB handover
•
SGW
Local Mobility Anchor point
for inter-eNodeB handover
Transport level packet
marking in the uplink and
the downlink
12. PGW Functions
Allocation of UE IP
addresses
•
Downlink packet marking
•
Service level charging,
gating and rate
enforcement
•
Mobility anchor 3GPP and
non-3GPP
•
11
Packet filtering, via deep
packet inspection
•
PGW
•
Terminates the SGi
interface towards the PDN
14. Services for LTE
LTE Services
• 3rd Party Content
• Operator Managed Content
• Video, Social Networking, WWW
LTE Network
• Is a transport/delivery network
• Can manage content QoS
• High capacity means many customers
Content Management
• IMS
• Service Delivery Platform
• LTE compatible with existing solutions
13
16. Policy Control
Application
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
PDP
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.
PEP
15
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.
17. Policy and Charging Rules Function
Billing
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
16
