LTE Backhaul: New Architectures for All-IP Thursday, June 11, 2009 Moderated by Patrick 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) Evolved Packet Core S1 interface X2 interface Iub interface Iu PS interface Iu CS interface Iub interface S1 interface ATM/IP IP

“LTE is the first genuinely all-IP wireless 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 Layers 1)Ethernet 2)Pseudowire (PW) 3)LSP VLAN Tag Switching Routed Non-Routed Static PW/MPLS T-MPLS (1) Data Plane Layer Ethernet MPLS-TPPBB-TE PW MPLS-TP LSP PW Eth BFD, Protection Protocol BFD, VCCV 802.1ag, 802.3ah, Y.1731 MPLS-TP-based COE IP/MPLS-Based COE PW MPLS LSP 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 Tunnel EthEth G.8031, 802.1ag, 802.3ah, Y.1731 Ethernet-based COE Ethernet (3) Data Plane Layers 1)Ethernet 2)Pseudowire (PW) 3)LSP (1) Control Plane Layer IP Ethernet + 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 RAN BS RAN NC Carrier Ethernet Access Network ENNI RAN BS UNI Carrier Ethernet Access Network ENNI RAN BS EVPL 1 EVPL 2 EVPL 3 EVPLAN

“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 DS1sEthernet Packet-optical networking platform with COE facilitates MBH network migration of multi-generation 2G/3G/LTE services EoS MSPP TDM Sonet DS1s Ethernet COE TDM Sonet DS1sEthernet COE TDM EoF Packet Optical Networking 2G/3G LTE 2G/3G 3G/LTE

“There is a big difference between 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 RequirementsDetails High Capacities Mbit/s per site Peak rate & average173 Mbit/s vs. 35 Mbit/s Low latency<10msec Handover interface (X2)E-LAN for eNBs Communication Enhanced servicesService-aware networks Deployment paradigmsHotspot the size of a city/rural BB Migration strategies TDM  Ethernet 2G  3G  LTE SynchronizationE1/T1 for legacy. 1588V2 & SyncE ConvergenceTrue multiplay operators

“ The differences in synchronization requirements 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 Sync E1/T1 TDM link Sync-Ethernet (G.8262) NTR – DSL/GPON TDM link Adaptive / IEEE Sync-E NTR FE/GbE IP Node B ETH S1 (ETH) aGW Packet Switched Network TDM/SONET Network Node B eNode B E1/T1 Packet-based Sync Adaptive 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 integration with 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 Wireless Carrier 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. A B C Ethernet Microwave

Ring site #3 Fiber site RNC Ring site #2 Wireless Carrier Ethernet Ring Tail site #1 Tail site #2 Tail site #3 Ring site #1 Packet or TDM based fiber aggregation network or leased lines A B C Sample Scenario: Carrier Ethernet Services in Mobile Backhaul #2 Ethernet Microwave

Ring site #3 Fiber site RNC Ring site #2 Wireless Carrier 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. A B C A 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

“The vast majority of wholesale backhaul providers and wireless operators will 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 Ethernet Access Ring (50ms) 4G G/W GigE MSC CT3/OC3 Mobile Operator B Fixed Wireless MSC CT3/OC3 4G G/W Mobile Operator A GigE 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 Wholesale Carrier 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