Advanced LTE, HSPA and EPC Cellular Systems Training - Public Seminars by Red Banana Wireless, register today at: http://4G-Seminar.com or contact us directly: info@4G-Seminar.com.

1. 1
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
Understanding 3GPP Bearers
LTE / HSPA / EPC
‘knowledge nuggets’
Neil Wiffen - nwiffen@red-banana.org
More free downloads at www.red-banana.org
Public Seminar details – www.4g-seminar.com

2. 2
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
QoS Characteristics
QoS Characteristics
QoS Characteristics
Traffic class, bit rate, delivery order, reliability, delay characteristics, priority etc.
Bearers for Quality of Service

3. 3
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
UMTS Bearer Hierarchy
End to End Service
Local
Bearer
Service
UMTS
Bearer
Service
External
Bearer
Service
Radio Access Bearer
Service
Core Network
Bearer Service
Backbone
Bearer
Service
Radio
Bearer
Service
Iu
Bearer
Service
UTRA
FDD/TDD
Service
Physical
Bearer
Service
Terminal
Equipment
Mobile
Equipment
UTRAN Core Network
Edge Node
Core Network
Gateway
Terminal
Equipment

4. 4
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
PS Radio Access Bearer (RAB)
UMTS Bearer Components
RNC
SGSN
MSC
Signalling Radio Bearers
CS Radio Bearers
PS Radio Bearer
Iu Signalling bearer
CS Data bearer
PS Data bearer
CS Radio Access Bearer (RAB)
PS Radio Access Bearer (RAB)
SGSN
PS Radio Bearer PS Data bearer
CN node

5. 5
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
EPS Bearer Hierarchy
S-GW
Application
Peer
P-GW
UE e-NB
End-to-end Service
EPS Bearer
E-RAB S5/S8 Bearer
Radio Bearer S1 Bearer
SGiS5/S8S1LTE-Uu
E-UTRAN EPC

6. 6
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
SGSN,
S-GW
GGSN,
P-GWBTS,
Nb,
eNb
GERAN,
UTRAN,
EUTRAN
GPRS CN,
UMTS CN,
EPC
IP-Connectivity Access Network
IP-CAN
Internet
IMS
Platform
Intranet
IP-PDN

7. 7
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
IP-CAN Bearers
SGSN GGSN
PS-RAB GTP-Tunnel
IP-CAN Bearer (PDP Context)
S-GW P-GW
LTE-Bearer GTP–Tunnel
IP-CAN Bearer
(EPS Bearer)
SGSN P-GW
PS-RAB
IP-CAN Bearer
S-GW
GTP-Tunnel
Interconnect / Roaming
support required
GTP–Tunnel
(EPS Bearer)

8. 8
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
LTE Connection components
MME
SGW PGW
PCRF
HSS
SPR
RBs GTP
Tunnel(s)
GTP
Tunnel(s)
GTP-C
Tunnel
SCTP
Association
SDFs
E-RABs
IP-CAN Bearer
IP Flow(s)
Application
Server
MNO
EDGE
Router
MNO
Domain
Application / SP
EDGE Router
ISP / Transit
Networks(s)

9. 9
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
• Radio Bearer
– L2 service provided for transfer of info on the Air Interface
– Describes L2 processes per bit-stream (flow)
– Different QoS requirements supported by different RBs
• Example
– Flow A requires low latency but can tolerate packet loss of 10-2
– Flow B has less stringent latency requirements, but can only tolerate a
packet loss of 10-6
– Flow A and B must be supported by 2 separate Radio Bearers
Radio Bearer (RB)

10. 10
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
• Signalling Radio Bearers (SRB)
– SRB0 is for RRC messages
• Using the CCCH logical channel
– SRB1 is for RRC / NAS messages
• Used prior to the establishment of SRB2
• Using DCCH logical channel
• NAS messages may be piggybacked inside RRC messages
• All messages are Integrity Protected and Ciphered after security activation
– SRB2 is for NAS messages
• Using DCCH logical channel
• May be contained in RRC messages, but with no RRC control content
• All messages are Integrity Protected and Ciphered after security activation
• Lower priority then SRB1
• Data Radio Bearers (DRB)
– Carry User Plane content on the Air Interface
LTE Radio Bearer categories

11. 11
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
Radio Bearers
SRB0
(RRC messages on CCCH)
Used for RRC connection setup
SRB1
(RRC / NAS messages on DCCH)
SRB2
(NAS messages on DCCH)
DRB2
(User content with QoS ‘B’ on DTCH2)
DRB1
(User content with QoS ‘A’ on DTCH1)
Multiple SRBs/DRBs to support
on-going user connection

12. 12
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
Bearer Mapping
MME
SGW
GTP-C
Tunnel
SCTP
Association
PGW
S1 GTP Tunnels
(S1 Bearers)
S5/S8 GTP Tunnels
(S5/S8 Bearers)
SRB RRC messages
Interpreted by UE / ENB
SRB NAS messages
Mapped to SCTP association
Interpreted by UE / MME
DRBs
Mapped to / from S1 Bearers
S1 Bearers
Mapped to/from
S5/S8 Bearers

13. 13
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
QoS and TFT
SGW PGW
UL Traffic Flow
Aggregates
DL Traffic Flow
Aggregates
UL TFT DL TFT
UL TFT  RB ID RB ID  S1 TEID S1 TEID  S5/S8 TEID
S5/S8 TEID  DL TFTRB ID  S1 TEID S1 TEID  S5/S8 TEID
EPS Bearer with defined QoS
Packet Filters -
applied to each
uplink IP-datagram
(QoS control)
Packet Filters -
applied to each
downlink IP-datagram
(QoS control)
UL / DL QoS
managed by
ENB scheduler
UL QoS
managed by
ENB ‘router’
DL QoS
managed by
SGW ‘router’

14. 14
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers
Backup Slides

15. 15
LTE / HSPA / EPC knowledge nuggets
Red Banana Wireless Ltd – Copyright 2013
www.red-banana.org
www.4g-seminar.com
Understanding 3GPP Bearers