lte evolved packet core
DESCRIPTION
EPS system descriptionTRANSCRIPT
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LTE Evolved Packet Core
2
Your Tutor - Tony Wakefield
British Telecom – Joined 1981
– National Certificates in
– Telecoms
– Electronics
– BSc (Hons) Electronics & Physics
Royal Navy for 8 Years
Telecoms Training since 1996
Training Director for Informa Telecoms Academy
Worked with many companies – Vodafone, O2, Orascom, MTN, ZAIN, ATOS, Motorola, Nokia, Ericsson ……..
Programme Director for Tel Mini MBA and Distance Learning, + Technology Training (SS7, CAMEL, 3G, GPRS, GSM, Bluetooth, WiMAX ……)
Hobby - Cycling
3
Agenda
Core Network Evolution
LTE EPC Architecture
EPC Node Functions
LTE EPC Operation
LTE EPC Protocols
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Core Network Evolution
5
Fixed – Next Generation Network (NGN)
DSL
network
PSTN
H.248
MEGACO
SIGTRAN
SS7
TDM
IP based
xDSL for local loop
Reduced capex/opex
Secure
May use IMS for voice or
service delivery
6
UMTS Architecture with IP Core
Internet
Gi
Node Bs
Illustrates combined:
Release 4
MSC MGW and server
Release 5
GSNs and IMS
7
Single Core Network, Seamless Service Delivery
IMS - New subsystem to Control Services (IP Multimedia Subsystem)
Supports IP-based multimedia services (real-time and non-real time)
Based on IETF standards and protocols (e.g. SIP and SDP)
Fixed and mobile implementations
IP core network
IP Multimedia
Subsystem
GSM
GPRS
3G
Fixed
Line
Wi-Fi
WiMAX
Service
Control
Service
Transport Access
Technologies
SIP
8
EPC Concept
New subsystem
Supports IP-based multimedia services (real-time and non-real time)
Based on IETF standards and protocols (e.g. SIP and SDP)
Fixed and mobile implementations
Evolved Packet Core
(IP core network)
IP Multimedia
Subsystem
GSM
GPRS
3G
Fixed
Line
Wi-Fi
WiMAX
Service control
Service
Transport
3GPP Access
Technologies
SIP
LTE eUTRAN
Non - 3GPP Access
Technologies
9
LTE Architecture (High Level)
External Networks
IMS, MMS, WAP,
Media Centres Interworking with trusted
and non-trusted networks
EPC – Evolved Packet Core
New Core Network - All IP for efficiency
Designed to provide efficient data transport
Flexible QoS / Bearer Allocation
WLAN UMTS
eNBs UE
E-UTRAN
New Radio Access Network
Brings Greater Efficiency,
Flexibility and Speed
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Terms – For Reference
LTE – Long Term Evolution
E-UTRAN – Evolved UMTS Terrestrial Radio Access Network
EPC – Evolved Packet Core
eNB – Evolved Node B
MME – Mobility Management Entity
SGW – Serving Gateway
PGW – Packet Data Gateway (Sometime PDN-GW)
UE – User Equipment
IMS – IP Multimedia Subsystem
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EPC Anchor Functions
12
AAA and Diameter
Radius and Diameter are
similar in function
Diameter offers better
session control, proxying
and security
Internet
Accounting
Time connected
Data volume
Number of
packets Diameter
AAA
server
Network
access
server
Access
point
Access – Request
Access – Accept or Reject
Laptop
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LTE EPC Architecture
14
LTE Architecture (High Level)
External Networks
IMS, MMS, WAP,
Media Centres Interworking with trusted
and non-trusted networks
EPC – Evolved Packet Core
New Core Network - All IP for efficiency
Designed to provide efficient data transport
Flexible QoS / Bearer Allocation
WLAN UMTS
eNBs UE
E-UTRAN
New Radio Access Network
Brings Greater Efficiency,
Flexibility and Speed
15
LTE Architecture – E-UTRAN
eNBs UE
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
E-UTRAN
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LTE Architecture – Evolved Packet Core (EPC)
EPC – Evolved Packet Core
New Core Network
All IP for efficiency
Self Organising Network (SON)
PGW – Packet Gateway
Connects to external networks
– Internet, IMS, WAP, MMS
Manages the IP session
MME – Mobility Management Entity
Overall control of UE and Data Sessions
Handle Handovers and Location Management
eNBs UE
SGW – Serving Gateway
Handles User Data
Controlled by the MME
17
LTE Architecture - Interworking
WLAN UMTS
eNBs UE
Interworking Defined interfaces for
interworking
UMTS/GPRS interworking
WiFi/WiMAX Interworking
Interworking with
Trusted/non-Trusted
18
LTE Architecture – Service Provision
External Networks
IMS, MMS, WAP,
Media Centres
WLAN UMTS
eNBs UE
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LTE Architecture – Defined Interfaces
External Networks
IMS, MMS, WAP,
Media Centres
EPC – Evolved Packet Core
New Core Network
All IP for efficiency
Self Organising Network (SON)
WLAN UMTS
eNBs
UE
SGi S2
S5
S3,S4,S12
S1-U
S1-MME
S11
X2
E-UTRAN
New Radio Access Network
Brings Greater Efficiency,
Flexibility and Speed
Interworking with trusted
and non-trusted networks
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EPC Node Functions
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SGW Functions
WLAN UMTS
SGi S2
S5
S3,S4,S12
S1-U
S1-MME
S11
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
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PGW Functions
WLAN UMTS
SGi S2
S5
S3,S4,S12
S1-U
S1-MME
S11
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
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MME Functions
WLAN UMTS
SGi S2
S5
S3,S4,S12
S1-U
S1-MME
S11
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
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LTE EPC Operation
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The Default Bearer
EPC
IMS IMS
VoIP App
LTE Network Establishes Initial Bearer
IP Address Allocated on registration
Must maintain an “always on” connection
Transfers SIP Signalling to IMS
Signalling (SIP)
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The Dedicated Bearer
EPC
IMS IMS
VoIP App
LTE Network Dedicated Bearer established with application
activation
Bearer properties negotiated with EPC
Bearer properties include QoS parameters
Signalling (SIP)
Media (RTP)
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QoS Class Identifier Values
EPS Bearer Properties
28
EPC Roaming Architecture – Home Routed
Traffic
29
EPC Roaming Architecture – Local Breakout
30
Policy and Charging Control Architecture
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LTE EPC Protocols
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S1 Interface Protocols
PHY
L2
UDP/IP
GTP-U
PHY
L2
IP
SCTP
S1AP
NAS
IP (user) S1-U Tunnelling Protocol Encapsulates
User IP Packets
S1-MME SCTP provides reliable transfer
of signalling over S1
S1AP provides eNB control from
the MME
33
S5/S8 Interface Protocols
PHY
L2
UDP/IP
GTP-U
IP (user) S5/S8 Tunnelling Protocol
Encapsulates User
IP Packets
34
S11 Interface Protocols
PHY
L2
UDP/IP
GTP-C
S11 Provides bearer
control mechanisms
for the user pane
35
S6 Interface Protocols
PHY
L2
IP
SCTP
Diameter
S6 MME – HSS Interface
Exchange of user data
Diameter-SCTP replaces SS7
HSS
