LTE Backhaul: New Architectures for All-IP Thursday, June 11, 2009 Moderated by Patrick Donegan...
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Transcript of LTE Backhaul: New Architectures for All-IP Thursday, June 11, 2009 Moderated by Patrick Donegan...
LTE Backhaul: New Architectures for All-IP
Thursday, June 11, 2009
Moderated byPatrick Donegan
Senior Analyst
Virtual Tradeshow
Our Panelists
• Ran Avital, VP Marketing, Ceragon
• Ralph Santitoro,Director of Carrier Ethernet Market Development, Fujitsu Network Communications
• Eitan Schwartz, VP Pseudowire & Ethernet Access, RAD Data Communications
IP
Voice Core (MSC)
3G W-CDMA Architecture
4G LTE Architecture
Data Core (SGSN/GGSN)
EvolvedPacket CoreS1 interface
X2 interface
Iub interface
Iu PS interface
Iu CS interface
Iub interface
S1 interface
ATM/IP
ATM/IP
IP
“LTE is the first genuinely all-IPwireless standard. It requires IP/MPLS routing in every node in the network, including throughout the backhaul.”
The statement below should be considered as a debating point – not as an opinion of Heavy Reading.
Technology Options For Connection-Oriented Ethernet (COE)Significant Differences Among Number of Layers to Manage
IP/MPLS
(3) Data Plane Layers1) Ethernet2) Pseudowire (PW)3) LSP
VLAN TagVLAN TagSwitchingSwitching
Routed Non-Routed
StaticPW/MPLS T-MPLS
(1) Data Plane Layer• Ethernet
MPLS-TP PBB-TEPBB-TE
PW
MPLS-TP LSP
PWEth Eth
BFD, Protection ProtocolBFD, VCCV
802.1ag, 802.3ah, Y.1731
MPLS-TP-based COEIP/MPLS-Based COE
PW
MPLS LSP
Eth Eth
BFD, RSVP-TE/LDP, FRR
802.1ag, 802.3ah, Y.1731
IS-IS, OSPF, BGP, IP addressing, BFD
PW
T-LDP/BFD, VCCV
S-VLAN or PBB-TE TunnelS-VLAN or PBB-TE Tunnel
EthEth EthEth
G.8031, 802.1ag, 802.3ah, Y.1731G.8031, 802.1ag, 802.3ah, Y.1731
Ethernet-based COEEthernet-based COE
Ethernet
(3) Data Plane Layers1) Ethernet2) Pseudowire (PW)3) LSP
(1) Control Plane Layer• IP
Ethernet+PW+LSPEthernet+PW+LSP
Ethernet-based COE simplifies OAM&P Only 1 Layer to manage: Ethernet
“The X2 interface between eNode Bs will only support a little
bit of cell handover traffic initially – it probably won’t be used
for anything more than that.”
The statement below should be considered as a debating point – not as an opinion of Heavy Reading.
Proposed LTE Architecture• Example 3
• Backhaul for LTE• EVPL for S1 interface• E-LAN for X2 interface
Carrier Ethernet Aggregation Network
UNI UNIRAN BS RAN NC
Carrier Ethernet Access Network
ENNI
RAN BS
UNI
Carrier Ethernet Access Network
ENNI
RAN BS
EVPL 1EVPL 2EVPL 3EVPLAN
“Most integrated fixed and wireless carriers will implement an L3-based backhaul for LTE because they already have the L3
engineering skill-sets”
“Most pure-play wireless operators and wholesale backhaul providers will implement
an L2 backhaul network – because they don’t.”
The statements below should be considered as a debating point – not as an opinion of Heavy Reading.
• Wholesale backhaul providers typically prefer L2: • Simpler to provision• Scalable BW “pipes” for unpredictable needs• Strong Ethernet OAM mechanisms offer SLA• Sub 50ms failover with 802.3ad and G.8032• Pseudowire helps support 2G/3G services, in addition to LTE• Powerful diagnostic tools
• “Pure-Play” wireless operators typically prefer L2:• Simple / automatic provisioning• Ethernet circuit validation, PM, fault detection and analysis• Traffic engineering oversubscribe link bandwidth
• Integrated carriers may prefer L3 (skill sets)• Mesh, alternate routing, but less developed OAM
L2/L3 Backhaul Challenges
Audience Poll “As LTE is an all-IP network, it will require
routing at every node in the network, including all the backhaul nodes.”
To what extent do you agree or disagree?
• Strongly agree• Somewhat agree• Neither agree nor disagree• Somewhat disagree• Strongly disagree
Multi-Generation Backhaul“Transporting legacy 2G and 3G cellular traffic
over the existing TDM network while LTE is transported over a separate
packet backhaul is optimal.”
“Better that than trying to emulate2G and 3G over a single packet backhaul for all
generations of cellular traffic.”
The statements below should be considered as a debating point – not as an opinion of Heavy Reading.
Evolution From Sonet To Packet-Based Ethernet MBH
FMO Step 1: Add COE over Sonet
to increase bandwidth efficiency
PMO: Sonet
Sonet
FMO Step 2: Begin Migration to EoF
packet network. Existing services unaffected
DS1s Ethernet
Packet-optical networking platform with COE facilitates MBH network migration of multi-generation 2G/3G/LTE services
EoS
MSPP
TDM
Sonet
DS1s Ethernet
COETDM
Sonet
DS1s Ethernet
COETDM
EoF
Packet Optical
Networking
Packet Optical
Networking
2G/3G 2G/3G LTE 2G/3G 3G/LTE
“There is a big differencebetween backhaul equipment
being Ethernet-ready and being LTE-ready.”
The statement below should be considered as a debating point – not as an opinion of Heavy Reading.
LTE Backhaul Requirements (…and the radio perspective)
14
Requirements DetailsHigh Capacities 50-200 Mbit/s per sitePeak rate & average 173 Mbit/s vs. 35 Mbit/sLow latency <10msecHandover interface (X2) E-LAN for eNBs CommunicationEnhanced services Service-aware networksDeployment paradigms Hotspot the size of a city/rural BBMigration strategies TDM Ethernet 2G3GLTESynchronization E1/T1 for legacy. 1588V2 & SyncEConvergence True multiplay operators
“The differences in synchronizationrequirements between
3G and LTE are academic.”
“This is because most operators are going to leave a T1/E1 at the cell site for packet backhaul synchronization
rather than adopt a new standard, none of which is mature yet.”
The statements below should be considered as a debating point – not as an opinion of Heavy Reading.
Multi-Generation Backhaul with Multiple Synchronization Options
TDM
ATM IMA
TDM
ATM
2G BSC
3G RNC
ETH
SHDSL
ATM IMA
IP-DSLAM
Physical-layer SyncE1/T1 TDM link
Sync-Ethernet (G.8262)
NTR – DSL/GPON
TDM link
Adaptive /IEEE 1588-2008
Sync-E
NTR
FE/GbE
IP Node B
ETH
S1 (ETH)
aGW
PacketSwitchedNetwork
TDM/SONETNetwork
Node B
eNode B
E1/T1
E1/T1
Packet-based SyncAdaptive
1588-2008
NTP
Sync-E
“LTE’s All-IP architecture will leave the backhaul open to security attacks on a far greater scale than ever before.”
“A lot of operators haven’t thought the implications through nearly well enough.”
The statements below should be considered as a debating point – not as an opinion of Heavy Reading.
Security With Connection-Oriented Ethernet
• COE uses few protocols. IP & MPLS require many• The more protocols used, MBH network is more susceptible to attacks
• Management VLANs isolated from user traffic• Similar to DCC isolation from user traffic in Sonet networks
• COE has many security advantages over bridged solutions• COE disables MAC address learning / flooding
• MAC address spoofing cannot occur
• MAC table overflow DOS attacks cannot occur
• COE disables vulnerable Layer 2 control protocols (L2CPs)
• Protocol-based DOS attacks cannot occur
COE is immune to IP-based attacks & popular L2-based attacks
“With any new technology, it’s always the OAM that get’s left till last, and
IP/Ethernet backhaul is no different.”
“The OAM standards are not mature, particularly as regards integrationwith legacy TDM OAM systems.”
The statements below should be considered as a debating point – not as an opinion of Heavy Reading.
Sample Scenario:Carrier Ethernet Services in Mobile Backhaul #1
Ring site#3
Fiber site
RNC
Ethernet Microwave
Ring site#2
WirelessCarrier Ethernet
Ring
Tail site #1
Tail site #2
Tail site #3
Ring site#1
Packet or TDM based fiber aggregation
network or leased lines
End-to-end connectivity per service is verified
using periodic 802.1ag CCM messages between
service end points.
End-to-end connectivity per service is verified
using periodic 802.1ag CCM messages between
service end points.
AA
BB
CC
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ring site#3
Fiber site
RNC
Ring site#2
Wireless
Carrier EthernetRing
Tail site #1
Tail site #2
Tail site #3
Ring site#1
Packet or TDM based fiber aggregation
network or leased lines
AA
BB
CC
Sample Scenario:Carrier Ethernet Services in Mobile Backhaul #2
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ring site#3
Fiber site
RNC
Ring site#2
WirelessCarrier Ethernet
Ring
Tail site #1
Tail site #2
Tail site #3
Ring site#1
Packet or TDM based fiber aggregation
network or leased lines
No alternate path available for Service A.
Service connectivity failure is reported by service end
points.
No alternate path available for Service A.
Service connectivity failure is reported by service end
points.
AA
BB
CC
AA
Service B is restored using alternate path
over the ring.No service connectivity
alarm is generated.
Service B is restored using alternate path
over the ring.No service connectivity
alarm is generated.Services B & C now share the
same radio link resulting in higher traffic load.
QoS is used to provide service differentiation for high priority
and delay sensitive traffic.
Services B & C now share the same radio link resulting in
higher traffic load.QoS is used to provide service differentiation for high priority
and delay sensitive traffic.
Sample Scenario:Carrier Ethernet Services in Mobile Backhaul #3
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
Ethernet Microwave
“The vast majority of wholesale backhaul providers and wireless operatorswill design their packet backhaul for 2G and 3G as well as LTE.”
“And since 90% of wireless traffic will be 2G and 3G through 2014,
the LTE design requirements aren’t critical in today’s design assumptions.”
The statements below should be considered as a debating point – not as an opinion of Heavy Reading.
Transport Provider
E2E SLA Monitoring and Diagnostics
EthernetAccess Ring
(50ms)4G G/W
GigEGigE
MSC
CT3/OC3
MobileOperator B
FixedWirelessMSC
CT3/OC3
4G G/W
MobileOperator A
GigEGigE
Test Equip.
Mobile Operator E2E T1 & Ethernet Diagnostics
Test Equip.
Data VLANs – Carry BH traffic, OAM and test data. Mgt VLAN – Management and SLA statistics
NMS Portal
WholesaleCarrier Ethernet
MPLS
T1/E1
ETH
4G eNB
2G/3G
T1/E1
ETH
4G eNB
2G/3G
T1/E1
ETH
4G eNB
2G/3G
2G/3G/4G Backhaul Services over Ethernet/IP/MPLS