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PART I M O B I L E A N D P A C K E T N E T W O R K S

2 Mobile Backhaul and the New Packet E r a 7 Erik Salo and Juha Salmelin

2.1 Backhaul Network, Tiers and Costs , 7 V — ^

2.1.1 Backhaul Network Tiers 7 2.1.2 Backhaul Network Costs Distribution 8

2.2 Legacy Backhaul Networks . 9 2.2.7 Backhaul Basic Technologies 9 2.2.2 Backhaul Topology 10

2.3 Drivers for the M B H Network Change 10 2.3.1 Mobile Service Developments and Traffic Growth 13 2.3.2 Mobile Network Developments 16 2.3.3 Backhaul Cost-Efficiency Improvements . 18 2.3.4 Lower Operational Costs 19 2.3.5 Developments in General Transport 21

2.4 Packet Based Backhaul Networks 21 2.4.1 Physical Network and Topology 22 2.4.2 Logical Network and Protocol Layers 22

\ . • • • '

Foreword

Acknowledgements

List of Abbreviations

List of Contributors

1 Introduction Esa Metsdld, Juha Salmelin and Erik Salo

1.1 Why Read This Book 1.2 What is 'Mob i l e Backhaul ' 1.3 Targets and Scope of the Book 1.4 Organization of the Book

vi CONTENTS

2.5 Mak ing Transition to Packet Technology Networks - 22 2.5.1 Transition Strategies for Packet-Based Backhaul 23 2.5.2 Implementing Transition and Network Evolution 27

3 3GPP Mobile Systems / 29 Esa Metsdld /

3.1 3 G P P / 29 3.1.1 Radio Technologies and Backhaul 3.1.2 Organization 3.1.3 Specifications 3.1.4 Releases

3.2 2 G 3.2.1 Circuit Switched Traffic 3.2.2 Packet Switched Traffic

29 30 31 32 33 33 36

3.2.3 Abis V ' 37 3.3 3 G ' 38

3.3.1 Circuit Switched Traffic 40 3.3.2 Packet Switched Traffic 41 3.3.3 30 Air Interface Channels 42 3.3.4 FP MAC and RLC Protocols 43 3.3.5 HSDPA (HS-DSCH) and HSUPA (E-DCH) 45 3.3.6 lub 48 3.3.7 lur 50 3.3.8 lu-cs 50 3.3.9 lu-ps 51 3.3.10 GTP-U Protocol 52

3.4 L T E 54 3.4.1 Architecture 54 3.4.2 Packet Switched Traffic 56 3.4.3 Air Interface . 5g 3.4.4 SI 58 3.4.5 X2 59 3.4.6 Bearers 60 3.4.7 Mobility Management 61 3.4.8 Interworking with 2G and 3G 63 3.4.9 Voice Support 63 3.4.10 Self Configuration and Self-Optimization 64

3.5 Summary 64 References 65

4 Packet Networks 68 Esa Metsdld

4.1 Mobi l e Backhaul Appl icat ion 68 . 4.1.1 Backhaul Sen/ice 68

4.1.2 Access, Aggregation and Core 70 4.1.3 3GPP Guidance for the Backhaul 71 4.1.4 Networking and Backhaul 72

CONTENTS vii

Standardization \ 73 4.2.1 IEEE 73 4.2.2 IETF 74 4.2.3 ISO ; ... _ . 74

4.2.4 ITU-T / •• , •• : 74 4.2.5 MEF / "̂^ 4.2.6 IP/MPLS Forum . .r::- 75 Physical Interfaces , . 76 4.3.1 High Data Rates 76 4.3.2 Ethernet Ports , - 77 4.3.3 El/Tl/JTl : - • . 77 4.3.4 SDH/Sonet . 79 PPP and M L - P P P ^ 80

4.4.1 PPP over El/Tl/JTl I ^ 80 4.4.2 ML-PPP l l ' 81 4.4.3 PPP over Sonet/SDH I 83 Ethernet and Carrier Ethernet 83 4.5.1 Carrier Ethernet 84 4.5.2 Ethernet and Ethernet Bridging 85 4.5.3 Ethernet Link Aggregation 87 4.5.4 VLANs 87 4.5.5 Class of Service 88 4.5.6 VLAN Example 88 4.5.7 Ethernet OAM 89 4.5.8 Provider Bridging 91 4.5.9 Provider Backbone Bridging 92 4.5.10 MPLS Based Carrier Ethernet 92 IP and Transport Layer Protocols 92 4.6.1 IP 93 4.6.2 IP Addresses and Address Assignment 96 4.6.3 Forwarding 99 4.6.4 Routing Protocols 100 4.6.5 Differentiated Services 101 4.6.6 Address Resolution Protocol 102 4.6.7 ICMP 102 4.6.8 UDP 103 4.6.9 RTP • 104 4.6.10 TCP 105 4.6.11 SCTP 107 4.6.12 IPv6 108 M P L S / I P Applications 109 4.7.1 MPLS Architecture 110 4.7.2 Label Distribution Protocol 111 4.7.3 BGP 111 4.7.4 MPLS Ping 113 4.7.5 MPLS L3 VPN and MP-BGP 113 4.7.6 Pseudowire Emulation Edge to Edge 116

4.7.7 MPLS L2 VPN-VPLS 4.7.8 MPLS-TE 4.7.9 MPLS-TP

4.8 Summary References

5 Backhaul Transport Technologies Jouko Kapanen, Jyri Putkonen and Juha Salmelin

5.1 Transport Systems 5.7.7 OSI-Model 5.1.2 Access Schemes 5.1.3 Plesiochronous Digital Hierarchy (PDH) 5.1.4 Synchronous Digital Hierarchy (SDH) 5.1.5 SDH Protection 5.1.6 Optical Transport Hierarchy (OTH) J 5.7.7 Next Generation SDH (NG-SDH) I 5.1.8 Asynchronous Transfer Mode (ATM) 5.1.9 Hybrid TDM/Packet

5.2 Wireless Backhaul Technology 5.2.7 Radio Wave Propagation 5.2.2 Frequencies and Capacities 5.2.3 Network Topologies 5.2.4 Availability and Resiliency 5.2.5 Performance 5.2.6 Other Wireless Technologies

5.3 Wire-Line Backhaul Technology 5.3.1 DSL Technologies 5.3.2 Optical Technology 5.3.3 Ethernet Interfaces 5.3.4 Ethernet in the First Mile 5.3.5 DOCSIS

5.4 Aggregation and Backbone Tiers 5.5 Leased Line Services for Mobi l e Backhaul

5.5.7 Ethernet Services and SLA's (MEF) 5.5.2 Leased Ethernet Service Offering 5.5.3 IP as a Backhaul Service

5.6 Summary ' References

P A R T II M O B I L E B A C K H A U L F U N C T I O N A L I T Y

6 Synchronization Antti Pietiidinen and Juha Salmelin

6.1 Cellular Networks Synchronization Requirements 6.7.7 Frequency Accuracy

CONTENTS ix

6.1.2 Time Accuracy 168 6.2 Frequency Synchronization in T D M Networks 169

6.2.1 Synchronization Architecture in TDM Networks 169 6.2.2 PDH I 170 6.2.3 SDH/SONET / 171 6.2.4 ATM / 172 6.2.5 OTN 172

6.3 Frequency Synchronization in Packet Networks - i 172 6.3.1 ACR (Adaptive Clock Recovery) , 173 6.3.2 NTP V 173 6.3.3 PTP Protocol 174 6.3.4 ITU PTP Telecom Profile for Frequency

Synchronization \11 6.3.5 Synchronous Ethernet - 179 6.3.6 Chaining Different Synchronization Technologies 180 6.3.7 Summary of ITU Recommendations Related to Frequency

Synchronization in Packet Networks 180 6.3.8 TICTOC 181

6.4 Synchronization Metrics for T D M and Synchronous Ethernet 182 6.4.1 Stability Metric MTIE 182 6.4.2 Relationship between TDM Wander Specification

and Base Station Clock Accuracy 184 6.4.3 TDEV 185

6.5 Packet Synchronization Fundamentals and Metr ics 187 6.5.1 The Principles of Packet Timing for Frequency

Synchronization 187 6.5.2 Packet Delay Metrics for Frequency

Synchronization 192 6.5.3 Two-way Messaging 198 6.5.4 Delay Jumps 198 6.5.5 Testing Packet Timing Slaves 198

6.6 Rules of Thumb for Packet T iming Network Implementation 199

6.7 Time Synchronization 201 6.71 GNSS Systems ••• 201 6.7.2 PTP for Time Synchronization s 202

6.8 Conclusions 202 References 203

7 Resilience 204 Esa Metsdld

7.1 Introduction 204 7.1.1 Restoration and Protection 204 7.7.2 Recovery 205 7.7.i Availability 206 7.1.4 MTBFandMTTR 207

7.1.5 Increasing Availability 7.1.6 Network Failures 7.1.7 Human Errors Native Ethernet and Resihence 7.2.1 Ethernet Bridging 7.2.2 Spanning Tree Operation Carrier Grade Ethernet 7.3.1 Carrier Ethernet . 7.3.2 MEF Services ' 7.3.3 Ethernet OAM IP Layer ' 7.4.7 VRRP 7.4.2 Load Sharing j 7.4.3 Routing Protocols I 7.4.4 OSPF \ 7.4.5 BED ' 7.4.6 Further Topics 7.4.7 Loop Free Alternates M P L S Resilience 7.5.7 Label Allocation 7.5.2 LDP Sessions 7.5.3 IP MPLS VPN 7.5.4 VPLS 7.5.5 MPLS TE and Fast Reroute 7.5.6 MPLS OAM 7.5.7 MPLS-TP 7.5.8 GMPLS Control Plane Resilience in the B T S Access • 7.6.7 BTS and BTS Site • . 7.6.2 BTS Access 7.6.3 IP Addressing 7.6.4 Active-Passive Ports 7.6.5 IP Load Sharing 7.6.6 Ethernet Link Aggregation 7.6.7 OSPF in the Access 7.6.8 Static Routes 7.6.9 First Hop Gateway Redundancy 7.6.10 Microwave Access Links 7.6.11 Attachment to a MEF Service Resilience in the Controllers and the Core Interface 7.7.7 BSC and RNC and Their Site Solutions 7.7.2 VRRP Example 7.7.3 Signaling Resilience with SCTP Multihoming 7.7.4 Use of Multiple Core Network Nodes Summary

CONTENTS

8 QoS 250 Thomas Deifi, Jouko Kapanen, Esa Metsaid and Csaba Vulkan

8.1 End User Service, Radio Network Layers and the Transport Layer Service 250 8.1.1 Transport Layer Service / . " 251 8.1.2 End-to-End QoS / • - • 251 8.1.3 Need for Backhaul QoS / 252 8.1.4 QoS Alignment with Radio and Backhaul 254 T C P and U D P as End User Transport Layer Protocols 255 8.2.1 UDP \ • 256 8.2.2 TCP 256 8.2.3 TCP Congestion Control 257 8.2.4 TCP Over Wireless 262 D S C P Traffic Class, and Priority Bits 263 8.3.1 Differentiated Services h 263 8.3.2 IPv6 jf 265 8.3.3 Per-Hop Behaviours 265 8.3.4 Recommended Use of DSCPs and Treatment Aggregates 266 8.3.5 DSCP in IP Tunnels 268 8.3.6 Use of DSCPs for Mobile Backhaul 268 8.3.7 MPLS Traffic Class 270 8.3.8 IEEE802.1Q Priority Bits 270 8.3.9 VLANs 273 8.3.10 QoS with MEF Services 273 Ingress and Egress Functions 275 8.4.1 Ingress Classification and Policing 275 8.4.2 Single-Rate Two Color Policer 276 8.4.3 Two-Rate Three Color Policer 276 8.4.4 Egress Scheduling, Queue Management, and Shaping 276 8.4.5 Strict Priority Scheduler 277 8.4.6 Weighted Round Robin Scheduler 277 8.4.7 Weighted Fair Queuing 277 8.4.8 Combined Schedulers ^ 278 8.4.9 Buffering 279 8.4.10 Tail Drop 279 8.4.11 Active Queue Management 280 8.4.12 Shaping 280 2G 281 8.5.1 Native PCM-Based Abis 281 8.5.2 Abis Over Pseudowire 281 8.5.3 Abis Example 281 3G/HSPA 282 8.6.1 Bearers and Their Attributes 282 8.6.2 lub 283 8.6.3 lub Example 285 8.6.4 Congestion Control in MBH 288

8.6.5 Congestion Control in HSPA Systems 8.6.6 HSDPA Congestion Control 8.6.7 HSUPA Congestion Control 8.6.8 Co-existence of Radio Networks

8.7 L T E 8.7.1 QoS Architecture 8.7.2 Packet Flows and Bearers 8.7.3 QoS Parameters 8.7.4 Admission Control 8.7.5 S] Interface 8.7.6 SI Example

8.8 Summary References

Security Esa Metsdld and Jose Manuel Tapia Perez

9.1 Security in 3 G P P Mobi l e Networks 9.1.1 Network Domain Security 9.1.2 2G 9.1.3 Abis, A and Gb 9.1.4 3G 9.1.5 lub 9.1.6 lu-cs, lu-ps and lur Interfaces 9.1.7 LTE 9.1.8 SI and X2 Interfaces 9.1.9 Management Traffic

9.2 Protection of the Backhaul 9.2.1 Cryptographic Protection Compared to Other Protection 9.2.2 Leased Service and A Self-Deployed Backhaul 9.2.3 Traffic Separation 9.2.4 Ethernet Services 9.2.5 IEEE 802.1x and IEEE802.Iae 9.2.6 MEF

9.3 IP Layer Protection 9.3.1 IPsec 9.3.2 IPsec SA 9.3.3 IPsec ESP

J 9.3.4 IPsec AH 9.3.5 IKE Protocol 9.3.6 Anti-Replay Protection 9.3.7 Network Element Authentication 9.3.8 Firewalls and Access Control Lists 9.3.9 Network Control Protocols Protection

9.4 IP Sec V P N Deployment 9.4.1 Cell and Hub Site Solutions ^• 9.4.2 IPsec Profiles

' 9.4.3 VPN Resilience

CONTENTS rfU

9.4.4 Fragmentation 336 9.4.5 IPsec and Quality of Service 337 9.4.6 LTE SI and X2 Study Case 340

9.5 Summary 344 References / 344

10 Packet Backhaul Solutions 346 Erik Salo and Juha Salmelin 10.1 Creating a Packet Based M B H Solution 1 346 10.2 M B H Solution Starting Points , ' 347

10.2.1 Hard Starting Points 348 70.2.2 Soft Starting Points I 348

10.3 M B H Optimization Considerations 349_ 10.3.1 Economic Optimization 349 10.3.2 Technical Optimization V 350 10.3.3 Optimization for a Particular Operator 350 10.3.4 Optimization for a Certain Region 351 10.3.5 Optimization for Flexibility 351 10.3.6 Optimization of Implementation 351

10.4 M B H Solution Alternatives 352 70.4.7 Enhancing SDH/Sonet Networks with NG-SDH/MSPP

Equipment 352 70.4.2 Enhancing SDH/Sonet Networks with a Packet Overlay 353 10.4.3 Fully Packet Based Networks for MBH Backbone and

Aggregation 356 70.4.4 Building Fully Packet Based MBH Access Network

for New Base Stations 357 70.4.5 Building Fully Packet Based MBH Access

Networks Area by Area 360 70.4.6 Other Possible Approaches/Strategies 360

10.5 Outsourcing the M B H Network or Parts o f it 360 70.5.7 Economic Considerations , .̂ 361 70.5.2 Strategic and Organizational Considerations 361 70.5.1 Technical Issues 362

10.6 Selecting M B H Access Solution for a Particular Case ,^ 363 70.6.7 MBH Solution for LTE in a Dense Urban Area

(in a Developed Environment) 364 70.6.2 MBH Solution for Suburban Area for 3G + LTE

(in a Developed Environment) 366 70.6.i MBH Solution in a Rural Area for a New 3G Network 367

10.7 From the Selected M B H Solution to Detailed Network Plans 368 10.8 Summary 369

11 Summary 370 Esa Metsdld and Juha Salmelin

Index 373