Wireless over Pseudowires

Presented by:Giles Heron
Director of Data Network Consulting
October 31st 2006

Agenda The challenge of mobile backhaul
 “Wireless over Pseudowires”
 Reference designs
 Synchronisation
 Future migration to all-IP

2

10 November, 2006

1

3G Services are Driving Capacity Growth
Goal: Improve Performance Plus Reduce cost of delivery?

?

Services

Data Rates

2mbps

14.4mbps

14.4mbps

Enablers

UMTS

HSDPA

HSUPA

MobileRAN
ReleasesATM
Rel 99ATMRel 43IP
Rel 5

10 November, 2006

Backhaul is The Missing Link
Terminals

Applications & Core

Applications
Application
environmentGaming
TVVideo on Demand

Enhanced
Network ServicesIMSImaging
MusicRadio Technologies?

GPRS

SGSN GGSN
IPnetwork
IPbackbone

Navigation
Internet
Remote working

EDGE

MGW

UMTS
HSDPA
WiFi
WiMAXDVB-H (Mobile-TV)

Backhauling RAN infrastructure will have heavy commercial impact
 20-30% of operator OPEX is spent in backhauling today
 Many of the mobile broadband enablers are already Ethernet-based Operator spending moves from radio infrastructure to transport

4

10 November, 2006

2TDM

PSTN /PLMN

The Challenge of Future Proof Backhaul
Applications

BTSBSCISUPSIPIMSBTS

Application
environment

Enhanced
Network Services

BSC

SGSN

GGSN

CSCF

TDM

IP
MGCF backbone

S
G PR
E
EDG

NodeB

RNC

NodeB

RNC

TDM

Internet

PSTN /PLMN

MGW

R99P
HSD

A

ATMA
UP
HSN
LA X
W
A
iM H
W BV
DRNC

RNC

NodeB

NodeB

IP

510 November, 2006

3G Backhaul Using MPLSCAPEX Savings vs. TDM Backhaul
Transport CAPEX Comparison - 8xE1
12,05,010,04,08,0

Number of Node Bs

Number of Node Bs

SDH transport and ATM switching at RNC site
RNC Application (“MPLS” aggregation box directly in front of RNC)
Hub Application (MPLS aggregation boxes distributed to hub sites)

610 November, 2006

31900

1500
1700

1100
1300

90070
0100

1900

1700

1500

1300

90
00,0
1100

2,00,070
0

1,050
0

4,030
02,050
0

6,030
0M€

3,0100M€

Transport CAPEX Comparison - 4xE1
6,0

3G Backhaul Using MPLS
NETEX Savings vs. TDM Backhaul

NodeBATMswitch

Long-Lined E1s

RNC

Short-Haul E1sMetro Ethernet
PEPERNC

710 November, 2006

Agenda The challenge of mobile backhaul
 “Wireless over Pseudowires”
 Reference designs
 Synchronisation
 Future migration to all-IP

810 November, 20064

UMTS Backhaul Using MPLS
ATM VP Transport
VPI = 1NodeB

VPI = XN x E1IMAATM PWE

STM-1
ATM

RNC

VPI = YVPI = 1ATM Cell
VC LabelTunnel LabelL2 Header+ Simple to provision- Inefficient transport- Requires CBR QoS for VP

PW Encapsulation
910 November, 2006

UMTS Backhaul Using MPLS
ATM VC Transport

NodeB

N x E1IMAATM PWE

VPI =STM-1
ATMRNC1VPI = X
VPI =1+ Frame-based transport for AAL5 VCs+ Enables IP termination at Hub formanagement and signalling traffic+ Enables per-VC QoS (CBR, VBR, UBR)
- Complex to provision1010 November, 2006

5

UMTS Backhaul Using MPLS
ATM VC cell Transport

NodeB

N x E1IMA

STM-1
ATM

ATM cell PWE

ATM Cell
ATM Cell
ATM Cell
VC LabelTunnel LabelL2 Header

Cell Cell Cell

RNC

Cell Cell CellPW Encapsulation

 Used to Transport
 Sync (AAL0)
 Bearer (AAL2)1110 November, 2006

UMTS Backhaul Using MPLS
ATM AAL5 SDU Transport

NodeB

N x E1
IMA

STM-1ATMATM AAL5 PWE

ATMSAR

Cell Cell Cell

ATMSAR

AAL5 SDU
Control Word
VC LabelTunnel LabelL2 Header

PW Encapsulation
12RNC

10 November, 2006

6Cell Cell Cell

 Used to Transport Signalling (QSAAL) Other data

UMTS Backhaul Using MPLS
IP/ATM Termination into RFC2547

NodeB

N x E1
IMAManagement
RouterCell Cell Cell

AAL5Term.

IP Packet
VPN Label
Tunnel LabelL2 Header

VPN Encapsulation

IP Packet
MAC Header

 Used to Transport Management (Mub) Signalling (SIGTRAN)

1310 November, 2006

CDMA 1xRTT Backhaul Using MPLS
HDLC Transport

BTS

T1chOC3HDLC PWE

HDLC Frame

HDLC FrameVC LabelTunnel LabelL2 Header

PW Encapsulation
14

10 November, 2006

7BSC

HDLC FrameGSM Backhaul Using MPLS
TDM Transport using SAToP or CESoPSNBTS

E1chSTM-1
BSC

TDM PWETDM Data
Control Word
VC LabelTunnel LabelL2 Header

PW Encapsulation
15

10 November, 2006

GSM - GPRS Backhaul Using MPLS
FR PWs Migrating to IP VPN

FR PWESGSN
BSC

FRPacket
PayloadIP
FR HeaderHeader
PPPFR
IP PayloadPacketControlWord
VPN Label
VC LabelTunnelLabel
TunnelLabel
L2 Header
L2 Header

VPN Encapsulation
PW Encapsulation
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10 November, 2006

8FRPayload
IP Packet
FRHeaderHeader
L2

 Gb interface becoming IP
 Enables SGSN pooling Requires IP-VPN for
GPRS backhaul

Agenda The challenge of mobile backhaul
 “Wireless over Pseudowires”
 Reference designs
 Synchronisation
 Future migration to all-IP

17

10 November, 2006

Reference Design
Rural Deployment – Optimising Capacity
 Capacity Today> Leased T1/E1 or PDH microwave from cell site to hub site
> Leased SONET/SDH (or SONET/SDH microwave) from hub to RNC site
 Solution: MPLS at Hub Site
> Maintain ATM or TDM T1/E1 circuits to hub site
> Use MPLS PWE from hub site to RNC site
– Enables clear-channel transport (plus option to use Ethernet if available)– Enables statistical gain between cell-sites

ATMATMRNC

ATM PWE

TDM
TDM PWE
TDM
MPLS Network18

10 November, 2006

9BSC

Reference Design
Suburban Deployment – Adding HSDPA
 Capacity Today> Leased T1/E1 or PDH microwave from cell site to hub site
> SDH/SONET from hub site to RNC site
 Solution: MPLS at Cell Site with DSL offload> Maintain ATM or TDM T1/E1 circuits to hub site
> Add wholesale ADSL capacity for 3G data using PWE over IP
BRAS
ADSL2+DSL Aggregation Network

DSLAM

IMA

PoS/GigE

RNC

ATM

ATM
TDM

TDM

BSC

TDM
MPLS Network
19

10 November, 2006

PWE over DSL Backhaul
Using MPLS over IP (RFC4023)
ATM
MPLS Pseudowire
PPPoA
L2TP

Node BDSL Modem

PE

LAC

DSLAM

LTS

LNS

RNC

PE

ATMATMATM

ATMATMATMATMATM

E1MPLS

MPLS

MPLS

MPLS

MPLS

MPLSSDHIPIP

IP

IP

IP

IP
Ethernet

Ethernet

20

STM-1

ADSL 2+FE

E1

PPP

PPP

PPP

PPP

VCmux

VCmux

L2TPL2TP

AAL5

AAL5

UDP

UDPATMATM

IP

IPDSLSDHSDH

Ethernet

10 November, 2006

10PWE over DSL Backhaul
Using MPLS over IP (RFC4023)
 “Overlay Network” causes control plane challenges> tLDP session as per RFC4447 can be used to provision PWs, but
failure detection will be slow
> VCCV-BFD from PE to PE provides faster detection> Need mechanism to notify DSL network failures to the RNC

BRAS
ADSL2+DSLAMIMADSL Aggregation Network

PoS/GigE

ATM

RNC

ATM
TDM

TDM
TDMBSCMPLS Network
21

10 November, 2006

Reference Design
Urban Deployment – Fibre to the Cell Site Capacity Today> Leased T1/E1 or PDH microwave from cell site to hub location> SDH/SONET from hub location to RNC site
 Solution: MPLS at Cell Site
> Use FE or GigE over fibre from cell site to hub location> Use GigE or 10GigE over fibre from hub site to RNC site

ATM

TDM
MPLS Network22

10 November, 2006

11RNCBSC

Agenda The challenge of mobile backhaul
 “Wireless over Pseudowires”
 Reference designs
 Synchronisation
 Future migration to all-IP

23

10 November, 2006

Synchronisation
Distributed
 Use external clock at each site
> Expensive proposition to provide a clock at every cell-site!

PRC

24

PRC

PRC

10 November, 2006

12

Synchronisation
Synchronous Physical Layer Synchronise all elements from the physical layer
 Distribute timing from one element to the next
 Well known and understood using SDH/SONET or E1/T1 circuits
 Ethernet Based> G.8261
 Good fit for rural and suburban scenarios above Good fit for urban scenario if deploying a dedicated network

OC-3

T1GigE

PRC
25

10 November, 2006

Synchronisation
Adaptive Timing
 Monitor jitter buffer levels
 Perform averaging and low pass filter to detect jitter> Tolerant to packet loss and reordering> Vulnerable to low frequency jitter components
 Two methods:> Synchronise each pseudowire> Synchronise node using “synchronisation pseudowire”

Synchronisation PW

OC-3

FE/GigE
GigE/10GigE

PRC
26

10 November, 2006

13Synchronisation
IEEE1588 Precision Time Protocol
 Hierarchical tree with master/slave clocks
 Designed for testing/automation applications> Being enhanced for telecom applications

IEEE1588
Slave
IEEE1588 PTP messa
ging

IEEE1588
GrandMaster
OC-3

FE/GigE
GigE/10GigE

PRC
27

10 November, 2006

Agenda The challenge of mobile backhaul
 “Wireless over Pseudowires”
 Reference designs
 Synchronisation
 Future migration to all-IP

28

10 November, 2006

14

3G Backhaul Using MPLS
Migration to R5

N x E1
ML-PPP
GigE

RNC

FE

IP Packet
PPP Header

IP Packet
VPN/VC Label
Tunnel LabelL2 Header

VPN or IP-PW Encapsulation

IP Packet
MAC Header

 All-IP Transport Voice Data Signalling Management29

10 November, 2006

Summary The Challenge of mobile backhaul
 “Wireless over Pseudowires”
 Reference Designs
 Synchronisation
 Future migration to all-IP
 Any Questions?

30

10 November, 200615