369,99 zł
Written by experts in the field, this book provides an overviewof all forms of broadband subscriber access networks andtechnology, including fiber optics, DSL for phone lines, DOCSIS forcoax, power line carrier, and wireless. Each technology isdescribed in depth, with a discussion of key concepts, historicaldevelopment, and industry standards. The book containscomprehensive coverage of all Broadband Access technologies, with asection each devoted to fiber-based technologies, non-fiber wiredtechnologies, and wireless technologies. The four co-authors'breadth of knowledge is featured in the chapters comparing therelative strengths, weaknesses, and prognosis for the competingtechnologies. Key Features: * Covers the physical and medium access layers (OSI Layer 1 and2), with emphasis on access transmission technology * Compares and contrasts all recent and emerging wired andwireless standards for Broadband Access in a single reference * Illustrates the technology that is currently being deployed bynetwork providers, and also the technology that has recently beenor will soon be standardized for deployment in the coming years,including vectoring, wavelength division multiple access, CDMA,OFDMA, and MIMO * Contains detailed discussion on the following standards:10G-EPON, G-PON, XG-PON, VDSL2, DOCSIS 3.0, DOCSIS Protocol overEPON, power line carrier, IEEE 802.11 WLAN/WiFi, UMTS/HSPA, LTE,and LTE-Advanced
Ebooka przeczytasz w aplikacjach Legimi na:
Liczba stron: 1007
Cover
Title Page
Copyright
Dedication
About the Authors
Acknowledgments
List of Abbreviations and Acronyms
Chapter 1: Introduction to Broadband Access Networks and Technologies
1.1 Introduction
1.2 A Brief History of the Access Network
1.3 Digital Subscriber Lines (DSL)
1.4 Hybrid Fiber-Coaxial Cable (HFC)
1.5 Power Line Communications (PLC)
1.6 Fiber in the Loop (FITL)
1.7 Wireless Broadband Access
1.8 Direct Point-to-Point Connections
Appendix 1.A: Voiceband Modems
Chapter 2: Introduction to Fiber Optic Broadband Access Networks and Technologies
2.1 Introduction
2.2 A Brief History of Fiber in the Loop (FITL)
2.3 Introduction to PON Systems
2.4 FITL Technology Considerations
2.5 Introduction to PON Network Protection
2.6 Conclusions
Appendix 2.A: Subscriber Power Considerations
References
Further Reading
Chapter 3: IEEE Passive Optical Networks
3.1 Introduction
3.2 IEEE 802.3ah Ethernet-based PON (EPON)
3.3 IEEE 802.3av 10Gbit/s Ethernet-based PON (10G EPON)
3.4 Summary Comparison of EPON and 10G EPON
3.5 Transport of Timing and Synchronization over EPON and 10G EPON
3.6 Overview of the IEEE 1904.1 Service Interoperability in Ethernet Passive Optical Networks (SIEPON)
3.7 ITU-TG.9801 Ethernet Passive Optical Networks using OMCI
3.8 Conclusions
Appendix 3.A: 64B/66B Line Code
References
Further Readings
Chapter 4: ITU-T/FSAN PON Protocols
4.1 Introduction
4.2 ITU-T G.983 Series B-PON (Broadband PON)
4.3 ITU-T G.984 Series G-PON (Gigabit-capable PON)
4.4 Next Generation PON (NG-PON)
Appendix 4.A: Summary Comparison of EPON and G-PON
References
Further Readings
Chapter 5: Optical Domain PON Technologies
5.1 Introduction
5.2 WDMA (Wavelength Division Multiple Access) PON
5.3 CDMA PON
5.4 Point-to-Point Ethernet
5.5 Subcarrier Multiplexing and OFDM
5.6 Conclusions
References
Further Readings
Chapter 6: Hybrid Fiber Access Technologies
6.1 Introduction and Background
6.2 Evolution of DOCSIS (Data-Over-Cable Service Interface Specification) to Passive Optical Networks
6.3 Radio and Radio Frequency Signals over Fiber
6.4 IEEE 802.3bn Ethernet Protocol over Coaxial Cable (EPoC)
6.5 Conclusions
References
Further Readings
Chapter 7: DSL Technology – Broadband via Telephone Lines
7.1 Introduction to DSL
7.2 DSL Compared to Other Access Technologies
7.3 DSL Overview
7.4 Transmission Channel and Impairments
7.5 DSL Transmission Techniques
References
Further Readings
Chapter 8: The Family of DSL Technologies
8.1 ADSL
8.2 VDSL
8.3 Basic Rate Interface ISDN
8.4 HDSL, HDSL2, and HDLS4
8.5 SHDSL
8.6 G.fast (FTTC DSL)
References
Chapter 9: Advanced DSL Techniques and Home Networking
9.1 Repeaters and Bonding
9.2 Dynamic Spectrum Management (DSM)
9.3 Vectored Transmission
9.4 Home Networking
References
Further Readings
Chapter 10: DSL Standards
10.1 Spectrum Management – ANSIT1.417
10.2 G.hs – ITU-T Rec. G.994.1
10.3 PLOAM – ITU-T Rec. G.997.1
10.4 G.bond – ITU-T Recs. G.998.1, G.998.2, and G.998.3
10.5 G.test – ITU-T Rec. G.996.1
10.6 G.lt – ITU-T Rec. G.996.2
10.7 Broadband Forum DSL Testing Specifications
10.8 Broadband Forum TR-069 – Remote Management of CPE
References
Chapter 11: The DOCSIS (Data-Over-Cable Service Interface Specification) Protocol
11.1 General Introduction
11.2 Introduction to MSO Networks
11.3 Background on Hybrid Fiber Coax (HFC) Networks
11.4 Introduction to DOCSIS
11.5 DOCSIS Network Elements
11.6 Brief History of the DOCSIS Protocol Evolution
11.7 DOCSIS Physical Layer
11.8 Synchronization and Ranging
11.9 DOCSIS MAC Sub-Layer
11.10 CM Provisioning
11.11 Security
11.12 Introduction to Companion Protocols
11.13 Conclusions
References
Further Readings
Chapter 12: Broadband in Gas Line (BIG)
12.1 Introduction to BIG
12.2 Proposed Technology
12.3 Potential Drawbacks for BIG
12.4 Broadband Sewage Line
Reference
Chapter 13: Power Line Communications
13.1 Introduction
13.2 The Early Years
13.3 Narrowband PLC*
13.4 Broadband PLC*
13.5 Power Grid Topologies*
13.6 Outdoor and In-Home Channel Characterization
13.7 Power Line Channel Modeling*
13.8 The IEEE 1901 Broadband over Power Line Standard
13.9 PLC and the Smart Grid*
13.10 Conclusions
References
Further Reading
Chapter 14: Wireless Broadband Access: Air Interface Fundamentals
14.1 Introduction
14.2 Duplexing Techniques
14.3 Physical Layer Concepts
14.4 Access Technology Concepts
14.5 Cross-Layer Algorithms
14.6 Example Application: Satellite Broadband Access
14.7 Summary
Further Reading
Chapter 15: WiFi: IEEE 802.11 Wireless LAN
15.1 Introduction
15.2 Technology Basics
15.3 Technology Evolution
15.4 WLAN Network Architecture
15.5 TV White Space and 802.11 af
15.6 Summary
Further Readings
Chapter 16: UMTS: W-CDMA and HSPA
16.1 Introduction
16.2 Technology Basics
16.3 UMTS Technology Evolution
16.4 CDMA2000
16.5 Summary
Further Readings
Chapter 17: Fourth Generation Systems: LTE and LTE-Advanced
17.1 Introduction
17.2 Release 8: The Basics of LTE
17.3 Release 9: eMBMS and SON
17.4 Release 10: LTE-Advanced
17.5 Future of LTE-Advanced: Release 11 and Beyond
17.6 IEEE 802.16 and WiMAX Systems
17.7 Summary
Further Readings
Chapter 18: Conclusions Regarding Broadband Access Networks and Technologies
Index
End User License Agreement
Table 2.1
Table 2.2
Table 3.1
Table 3.2
Table 3.3
Table 3.4
Table 3.5
Table 3.6
Table 4.1
Table 4.2
Table 4.3
Table 4.4
Table 4.5
Table 4.6
Table 4.7
Table 4.8
Table 4.9
Table 4.10
Table 6.1
Table 8.1
Table 8.2
Table 11.1
Table 11.2
Table 11.3
Table 11.4
Table 11.5
Table 13.1
Table 13.2
Table 13.3
Table 15.1
Table 15.2
Table 15.3
Table 17.1
Table 17.2
Table 17.3
Table 17.4
Table 17.5
Figure 1.1
Figure 1.2
Figure 1.3
Figure 1.4
Figure 2.1
Figure 2.2
Figure 2.3
Figure 2.4
Figure 2.5
Figure 2.6
Figure 2.7
Figure 2.8
Figure 2.9
Figure 2.10
Figure 2.11
Figure 2.12
Figure 2.13
Figure 2.14
Figure 2.15
Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 3.7
Figure 3.8
Figure 3.9
Figure 3.10
Figure 3.11
Figure 3.12
Figure 3.13
Figure 3.14
Figure 4.1
Figure 4.2
Figure 4.3
Figure 4.4
Figure 4.5
Figure 4.6
Figure 4.7
Figure 4.8
Figure 4.9
Figure 4.10
Figure 4.11
Figure 4.12
Figure 4.13
Figure 4.14
Figure 4.15
Figure 5.1
Figure 5.2
Figure 5.3
Figure 5.4
Figure 5.5
Figure 5.6
Figure 5.7
Figure 5.8
Figure 5.9
Figure 6.1
Figure 6.2
Figure 6.3
Figure 6.4
Figure 6.5
Figure 7.1
Figure 7.2
Figure 7.3
Figure 7.4
Figure 7.5
Figure 7.6
Figure 7.7
Figure 7.8
Figure 7.9
Figure 7.10
Figure 7.11
Figure 7.12
Figure 7.13
Figure 7.14
Figure 7.15
Figure 7.16
Figure 7.17
Figure 7.18
Figure 7.19
Figure 7.20
Figure 7.21
Figure 7.22
Figure 7.23
Figure 7.24
Figure 8.1
Figure 8.2
Figure 8.3
Figure 8.4
Figure 8.5
Figure 8.6
Figure 8.7
Figure 8.8
Figure 9.1
Figure 9.2
Figure 11.1
Figure 11.2
Figure 11.3
Figure 11.4
Figure 11.5
Figure 11.6
Figure 11.7
Figure 11.8
Figure 11.9
Figure 11.10
Figure 11.11
Figure 11.12
Figure 11.13
Figure 11.14
Figure 11.15
Figure 11.16
Figure 11.17
Figure 11.18
Figure 11.19
Figure 12.1
Figure 13.1
Figure 13.2
Figure 13.3
Figure 13.4
Figure 13.5
Figure 13.6
Figure 13.7
Figure 13.8
Figure 13.9
Figure 13.10
Figure 13.11
Figure 13.12
Figure 14.1
Figure 14.2
Figure 14.3
Figure 14.4
Figure 14.5
Figure 14.6
Figure 14.7
Figure 14.8
Figure 14.9
Figure 14.10
Figure 15.1
Figure 15.2
Figure 15.3
Figure 15.4
Figure 15.5
Figure 15.6
Figure 15.7
Figure 15.8
Figure 15.9
Figure 15.10
Figure 15.11
Figure 16.1
Figure 16.2
Figure 16.3
Figure 16.4
Figure 16.5
Figure 16.6
Figure 16.7
Figure 16.8
Figure 16.9
Figure 16.10
Figure 16.11
Figure 16.12
Figure 16.13
Figure 16.14
Figure 16.15
Figure 16.16
Figure 16.17
Figure 17.1
Figure 17.2
Figure 17.3
Figure 17.4
Figure 17.5
Figure 17.6
Figure 17.7
Figure 17.8
Figure 17.9
Figure 17.10
Figure 17.11
Figure 17.12
Figure 17.13
Figure 17.14
Figure 17.15
Figure 17.16
Figure 17.17
Figure 17.18
Figure 17.19
Figure 17.20
Figure 17.21
Figure 17.22
Figure 17.23
Figure 17.24
Figure 17.25
Figure 17.26
Figure 17.27
Figure 17.28
Figure 17.29
Figure 17.30
Figure 17.31
Cover
Table of Contents
Chapter 1
iii
iv
xv
xvi
xvii
xviii
xix
xx
xxi
xxii
xxiii
xxiv
xxv
xxvi
xxvii
xxix
xxx
xxxi
xxxii
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
Steve Gorshe
PMC-Sierra, Inc., USA
Arvind R. Raghavan
Blue Clover Devices, USA
Thomas Starr
Stefano Galli
ASSIA Inc., USA
This edition first published 2014
© 2014 John Wiley & Sons, Ltd
Registered office
John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom
For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com.
The right of the author to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher.
Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.
Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book.
Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. It is sold on the understanding that the publisher is not engaged in rendering professional services and neither the publisher nor the author shall be liable for damages arising herefrom. If professional advice or other expert assistance is required, the services of a competent professional should be sought.
Library of Congress Cataloging-in-Publication Data applied for
ISBN: 9780470741801
To my wife Bonnie Gorshe, and sons Alex and Ian Gorshe; S.D.G.
Steve Gorshe
To the Lord, in the spirit of Karma Yoga.
Arvind Raghavan
To my wife, Marilynn Starr.
Thomas Starr
To Tobey and Hannah.
Stefano Galli
Steve Gorshe is a Distinguished Engineer in the CTO organization of PMC-Sierra, Inc., where his work since 2000 has included technology development and telecommunications standards. He received his BSEE from the University of Idaho (1980) and both his MSEE (1982) and PhD (2002) degrees from Oregon State University. Since 1983, he has worked in product development, applied research, and systems architecture of telecommunications access and transport systems. His standards activity includes over 300 contributions across six standards bodies, serving as technical editor for nine North American and international standards, and currently serving as Associate Rapporteur for the Q11 group of ITU-T Study Group 15.
Steve is a Fellow of the IEEE. His IEEE activities include Communications Magazine Editor-in-Chief (2010–2012), Associate Editor-in-Chief (2006–2009), and Broadband Access Series co-editor (1999–2006). He has also served as the IEEE Communications Society Director of Magazines and Chair of the Transmission, Access and Optical Systems Technical Committee.
Steve has 37 patents issued or pending, over 24 published papers, and is co-author of two textbooks and co-author of chapters in three other textbooks.
Arvind R. Raghavan heads research and development at Blue Clover Devices, where he is involved with the design and implementation of innovative products for the Internet of Things, with current emphasis on Bluetooth Low Energy technology. Before joining Blue Clover Devices, he was part of the Radio Technology and Strategy group at AT&T Labs, where his work focused on the impact of QoS on LTE, design and analysis of heterogeneous networks, and advanced MIMO techniques for standardization in 3GPP. Prior to joining AT&T Labs, he played a lead role in the Systems Engineering group at ArrayComm, LLC, where they developed specifications for their multi-antenna signal processing products, conducted performance analyses, and made contributions to the standardization of WiMAX systems. Arvind holds MS and PhD degrees in Electrical Engineering from Clemson University.
Thomas Starr is a Lead Member of Technical Staff at AT&T Laboratories in Hoffman Estates, Illinois. Thomas is responsible for the development and standardization of local access and home networking technologies for AT&T's network. These technologies include ADSL, HDSL, SHDSL, VDSL and G.hn. In 2009, Thomas received the prestigious AT&T Science and Technology Medal. He serves as Chairman of the Broadband Forum and has also served as a member of the Board of Directors since its inception as the ADSL Forum in 1994. Thomas has been a distinguished fellow of the Broadband Forum From 1988 to 2000, has served as Chairperson of ANSI accredited standards working group T1E1.4, which develops xDSL standards for the United States, received the Committee T1 Outstanding Leadership Award in 2001, and now serves at ATIS COAST-NAI Chairman. In the ITU-T SG15, Thomas serves as Chairman of Working Party 1, addressing fiber, DSL, and home networking standards, and participates in the ITU SG15 Q4 group on xDSL international standards.
Thomas is a co-author of the books DSL Advances, published by Prentice Hall in 2003, and Understanding Digital Subscriber Line Technology, published by Prentice Hall in 1999. Thomas is also the author of the Science Fiction novel Virtual Vengeance. Thomas previously worked for 12 years at AT&T Bell Laboratories on ISDN and local telephone switching systems, and twenty US patents in the field to telecommunications have been issued to him. Thomas holds a MS degree in Computer Science and a BS degree in Computer Engineering from the University of Illinois in Urbana, Illinois.
Stefano Galli received his MS and PhD degrees in Electrical Engineering from the University of Rome “La Sapienza” (Italy) in 1994 and 1998, respectively. He is currently the Director of Technology Strategy of ASSIA – the leading developer of automated management and diagnostics tools for broadband networks. Prior to this position, he held the role of Director of Energy Solutions R&D for Panasonic Corporation and Senior Scientist at Bellcore.
Dr. Galli is serving as Chief Information Officer of the IEEE Communications Society (ComSoc), director of Smart Grid activities for the IEEE ComSoc Technical Committee on Power Line Communications, member of the Energy and Policy Committee of IEEE-USA, and as Editor for the IEEE Transactions on Communications and the IEEE Communications Magazine. Dr. Galli is also serving as Rapporteur for the ITU-T Q15/15 “Communications for Smart Grid” standardization group. Past positions include serving as Co-Chair of the “Communications Technology” Task Force of IEEE 2030 (Smart Grid), Leader of the “Theoretical and Mathematical Models” Group of IEEE 1901 (Broadband over Power Lines standard), Coexistence sub-group Chair of the SGIP/NIST PAP 15, elected Member-at-Large of the IEEE Communications Society (ComSoc) Board of Governors, and a variety of other leadership positions in the IEEE. He has also served as Founder and first Chair of the IEEE ComSoc Technical Committee on Power Line Communications.
Dr. Galli is a Fellow of the IEEE, has received the 2013 IEEE Donald G. Fink Best Paper Award for his paper on Smart Grid and Power Line Communications, the 2011 IEEE ComSoc Donald W. McLellan Meritorious Service Award, the 2011 Outstanding Service Award from the IEEE ComSoc Technical Committee on Power Line Communications, and the 2010 IEEE ISPLC Best Paper Award. He holds several issued and pending patents, has published over 90 peer-reviewed papers, has co-authored three book chapters on power line communications, and has made numerous standards contributions to the IEEE, the ITU-T, the Broadband Forum, and the UK NICC.
Thanks are given to the experts who provided assistance for the chapters on DSL technology: George Ginis, Ken Kerpez, Vladimir Oksman, Craig Schelp, Massimo Sorbara, and Arlynn Wilson. Thanks also are given to Marilynn Starr for her support and assistance.
Steve would like to thank the following people for their generous help, excellent comments and reviews for portions of his chapters: Frank Effenberger, Alon Bernstein, Chris Look, Onn Haran, Jeff Mandin, Lior Khermosh, Bob Murray, Valy Ossman, and Jim Dahl. Steve also wants to thank PMC-Sierra for allowing some of his white paper material to be adapted for this book.
Arvind would like to acknowledge the significant contributions of his wife, Sanchita Shetty, for painstakingly generating all the figures in the wireless chapters, and her unwavering support throughout the writing of this book. He would also like to express his heartfelt gratitude to Paul Chiuchiolo, Rich Kobylinski, Milap Majmundar, and Tom Novlan, for reviewing the wireless section of the book and providing excellent feedback for improving the quality and accuracy of the manuscript. Finally, he would like to thank his family and all his wonderful friends in Austin for their love and encouragement.
2G
Second Generation
3G
Third Generation
3GPP
Third Generation Partnership Project
10GE
10 Gigabit/s Ethernet specified in IEEE 802.3
10G EPON
10 Gbit/s Ethernet Passive Optical Network specified in IEEE 802.3
ABS
Almost Blank Subframes
AC
Alternating Current
AC
Access Category
ACK
Acknowledgement
ACM
Adaptive Coding and Modulation
ADC
Analog-to-Digital Converter
ADSL
Asymmetric Digital Subscriber Line specified in ITU-T G.992.1
ADSL2
Asymmetric Digital Subscriber Line 2 specified in ITU-T G.992.3
ADSL2plus
Asymmetric Digital Subscriber Line 2plus specified in ITU-T G.992.5
AES
Advanced Encryption Standard
AFE
Analog Front End
AICH
Acquisition Indicator Channel
AM
Acknowledged Mode
AMI
Advanced Metering Infrastructure
A-MPDU
Aggregate MAC Protocol Data Unit
AMPS
Advanced Mobile Phone System
AMR
Automatic Meter Reading
A-MSDU
Aggregate MAC Service Data Unit
ANSI
American National Standards Institute
AP
Access Point
APD
Avalanche Photo Diode
APS
Automatic Protection Switching
ARIB
Association of Radio Industries and Businesses
ARP
Allocation and Retention Priority
ARQ
Automatic Repeat Request, Retransmission
AS
Access Stratum
ASE
Amplified Spontaneous Emission
ASF
DOCSIS Aggregated Service Flow
A-TDMA
Advanced TDMA (used with DOCSIS)
ATIS
Alliance for Telecommunications Industry Solutions
ATM
Asynchronous Transfer Mode protocol
AWG
American Wire Gauge
AWG
Arrayed Waveguide Grating WDM filter/multiplexer
BB
Broad Band
BCCH
Broadcast Control Channel
BCH
Broadcast Channel
BE
Best Effort service
BEMS
Building Energy Management System
BER
Bit Error Rate (or Ratio)
BIP
Bit Interleaved Parity
BMC
Broadcast Multicast Control
BMSC
Broadcast Multicast Service Center
B-ONU
DPoE Bridge ONU
BPL
Broadband over Power Lines
B-PON
FSAN/ITU-T Broadband PON protocol specified in the ITU-T G.983 series
BRI-ISDN
Basic Rate Integrated Services Digital network
BSS
Basic Service Set
BTS
Base Transceiver Station (for a wireless network)
CA
Carrier Aggregation
CAPEX
Capital Expense
CAPWAP
Control and Provisioning of Wireless Access Points
CATV
Community Access Television
CBR
Constant Bit Rate
CBS
Committed Burst Size
CC
Component Carrier
CCA
Clear Channel Assessment
CCCH
Common Control Channel
CCK
Complementary Code Keying
CCO
Capacity and Coverage Optimization
CDD
Cyclic-Delay Diversity
CDMA
Code Division Multiple Access
CENELEC
European Committee for Electotechnical Standardization
CEPCA
Consumer Electronics Powerline Alliance
CES
Circuit Emulation Service
CFP
Contention Free Period
CIF
Carrier Indicator Field
CIR
Committed Information Rate
CM
Cable Modem
CMCI
DOCSIS Cable Modem CPE Interface
CMTS
DOCSIS Cable Modem Terminating System
CN
Core Network
CO
Telephone company Central Office
CoMP
Cooperative Multi-Point
CP
Contention Period
CP
Cyclic Prefix
CPC
Continuous Packet Connectivity
CPE
Customer Premises Equipment
CPICH
Common Pilot Channel
CPRI
Common Public Radio Interface
CQI
Channel Quality Information
CRC
Cyclic Redundancy Check
CRE
Cell Range Expansion
CRS
Cell-specific Reference Signal
CS
Circuit Switched
CS
Channel Sensing
CSA
Carrier Serving Area
CS/CB
Coordinated Scheduling/Coordinated Beamforming
CSG
Closed Subscriber Group
CSI-RS
Channel State Information Reference Signal
CSM
Collaborative Spatial Multiplexing
CSMA/CA
Carrier Sense Multiple Access with Collision Avoidance
CSO
Cell Selection Offset
CTCH
Common Traffic Channel
CTS
Clear-to-send
CTS
Common Technical Specification for G-PON
CV
Code Violation
C-VID
Customer VLAN Identifier (Ethernet)
CWDM
Coarse Wavelength Division Multiplexing
DAC
Digital-to-Analog Converter
DAS
Distributed Antenna System
dB
Decibel, ten times the common logarithm of the ration of two powers
DBA
Dynamic Bandwidth Assignment
DBC
Dynamic Bonding Change (in DOCSIS 3.0)
DBG
Downstream Bonding Group (in DOCSIS 3.0)
DBR
Dynamic Bandwidth Report
DC
Direct Current
DCCH
Dedicated Control Channel
DCF
Distributed Coordination Function
DCH
Dedicated Channel
DCS
Downstream Channel Set (in DOCSIS 3.0)
DELT
Dual Ended Line Test
DEMARC
Carrier owned Demarcation device between the carrier and the CPE
DER
Distributed Energy Resources
DFE
Decision Feedback Equalizer
DFT
Discrete-time Fourier Transform
DHCP
Dynamic Host Configuration Protocol
DIFS
Distributed Interframe Spacing
DL
Downlink
DLC
Digital Loop Carrier
DLL
Data Link Layer
DL-SCH
Downlink Shared Channel
DM-RS
Demodulation Reference Signal
DMT
Discrete Multi Tone modulation
DOCSIS
Data Over Cable Service Interface Specification
D-ONU
DPoE ONU
Downstream
Data flowing towards the customer
DPB
Dynamic Point Blanking
DPCCH
Dedicated Physical Control Channel
DPDCH
Dedicated Physical Data Channel
DPoE
DOCSIS Protocol over Ethernet protocol
DPS
Dynamic Point Selection
DPSK
Differential Phase Shift Keying
DQPSK
Differential Quadrature Phase Shift Keying
DR
Demand Response
DRX
Discontinuous Reception
DS
Direct Sequence
DS1
Digital Signal level 1 in the North American asynchronous telephone network hierarchy
DS-CDMA
Direct Sequence Code Division Multiple Access
DSCP
DiffServ Code Point
DSID
Downstream Service ID (in DOCSIS 3.0)
DSL
Digital Subscriber Line
DSLAM
DSL Access Multiplexer
DSM
Dynamic Spectrum Management (in DSL)
DSM
Demand Side Management (in Smart Grid)
DSP
Digital Signal Processing
DSSS
Direct Sequence Spread Spectrum
DTX
Discontinuous Transmission
DVB
Digital Video Broadcast
DVB-RCS
Digital Video Broadcast Return Channel via Satellite
DVB-S2
Digital Video Broadcasting - Satellite - Second generation
DWDM
Dense Wavelength Division Multiplexing
E-AGCH
Enhanced Absolute Grant Channel
EBS
Excess Burst Size
ECH
Echo Cancelled Hybrid
eCM
embedded Cable Modem
EDCA
Enhanced Distributed Channel Access
E-DCH
Enhanced Dedicated Channel
EDFA
Erbium Doped Fiber Amplifier
EDGE
Enhanced Data-rates for GSM Evolution
E-DPCCH
Enhanced Dedicated Physical Control Channel
E-DPDCH
Enhanced Dedicated Physical Data Channel
E-HICH
Enhanced HARQ Indicator Channel
eICIC
Enhanced Inter-Cell Interference Coordination
EIR
Excess Information Rate
eMBMS
Enhanced Multimedia Broadcast and Multicast Service
EMC
Electro-Magnetic Compatibility
EMS
Element Management System
EO
Electrical to Optical signal conversion
eOAM
Extended OAM messages used in DPoE
EOC
Embedded Operations Channel
EONT
Embedded ONT
eNodeB
Evolved Node-B
EPC
Evolved Packet Core
EPON
Ethernet Passive Optical Network (1 Gbit/s rate)
EPS
Evolved Packet System
E-RGCH
Enhanced Relative Grant Channel
eSAFE
embedded Service/Application Functional Entity
ESP
Ethernet Service Path
ESS
Extended Service Set
ETSI
European Telecommunications Standards Institute
E-UTRAN
Evolved UMTS Terrestrial Radio Access Network
EVC
Ethernet Virtual Circuit
EVSE
Electric Vehicle Supply Equipment
FACH
Forward Access Channel
FBI
Feedback Information
FCC
Federal Communications Commission
FCS
Frame Check Sequence
FDD
Frequency Division Duplexing
FDM
Frequency Division Multiplexing
FDMA
Frequency Division Multiple Access
F-DPCH
Fractional Dedicated Physical Channel
FEC
Forward Error Correction
FeICIC
Further Enhanced Inter-Cell Interference Coordination
FEXT
Far End crosstalk
FFT
Fast Fourier Transform
FH
Frequency Hopping
FH-CDMA
Frequency Hopping Code Division Multiple Access
FHSS
Frequency Hopping Spread Spectrum
FITL
Fiber in the Loop
FN
Fiber Node (in a HFC network)
FSAN
Full Service Access Network industry consortium
FSK
Frequency Shift Keying
FTTC
Fiber to the Curb
FTTCab
Fiber to the Cabinet
FTTCell
Fiber to the Cell site
FTTH
Fiber to the Home
FTTN
Fiber to the Node
FTTO
Fiber to the Office
FTTP
Fiber to the Premises
G.hn
ITU-T G.9960/9961 home networking standard
G.hs
ITU-T G.994.1 DSL handshake protocol
G.lite
ITU-T G.992.2 reduced complexity ADSL
G.lt
ITU-T G.996.2 standard for DSL line test functions
G.test
ITU-T G.996.1 standard for testing of DSL modems
GBR
Guaranteed Bit Rate
GE
Gigabit/s Ethernet
GEM
G-PON Encapsulation Method
GERAN
GSM Edge Radio Access Network
GFP
Generic Framing Procedure specified in ITU-T G.7041
GGSN
Gateway GPRS Support Node
GMSC
Gateway Mobile Switching Center
GP
Guard Period
G-PON
FSAN/ITU-T Gigabit-capable PON protocol specified in the ITU-T G.984 series
GPRS
GSM Packet Radio System
gPTP
generalized Precision Timing Protocol
GSM
Global System for Mobile communications
GTC
G-PON Transmission Convergence
HAN
Home Area Network
HARQ
Hybrid Automatic Repeat Request
HCF
Hybrid Coordination Function
HD-PLC
High Definition Power Line Communication
HDR
High Data Rate
HDSL
High bit rate Digital Subscriber Line
HDSL2
High bit rate Digital Subscriber Line, 2 wire version
HDSL4
High bit rate Digital Subscriber Line, 4 wire version
HE
Head End
HEC
Header Error Check
HEMS
Home Energy Management System
HetNet
Heterogeneous Network
HF
High Frequency
HFC
Hybrid Fiber-Coaxial cable network
HLR
Home Location Register
HSDPA
High Speed Downlink Packet Access
HS-DPCCH
High Speed Dedicated Physical Control Channel
HS-DSCH
High Speed Downlink Shared Channel
HSPA
High Speed Packet Access
HS-PDSCH
High Speed Physical Downlink Shared Channel
HS-SCCH
High Speed Shared Control Channel
HSS
Home Subscriber Server
HSUPA
High Speed Uplink Packet Access
HV
High Voltage
IAD
Integrated Access Device
ICIC
Inter-cell Interference Coordination
IEC
International Electrotechnical Commission
IED
Intelligent Electronic Devices
IEEE
Institute of Electrical and Electronic Engineers
IETF
Internet Engineering Task Force
IFS
Inter-Frame Spacing
IGMP
Internet Group Management Protocol
IMT
International Mobile Telecommunications
IP
Internet Protocol
IP-HSD
DOCSIS IP High-Speed Data service
IPP
Inter-PHY Protocol
IPTV
Television delivered over Internet Protocol
IPv6
Internet Protocol version 6
IR
Infra-Red
IR
Incremental Redundancy
IRC
Interference Rejection Combining
IS-54
A second generation cellular standard
IS-136
A second generation cellular standard, an improvement on IS-54ISI Intersymbol interference
ISI
Inter-symbol Interference
ISM
Industrial, Scientific, and Medical
ISO
International Organization for Standardization
ISP
Internet Service Provider
ISP
IEEE 1901 Inter System Protocol
ITU-T
International Telecommunication Union – Telecommunication Standardization Sector
JP
Joint Processing
JT
Joint Transmission
kft
kilofeet (length of wire)
L1
Layer-1
L2
Layer-2
L3
Layer-3
LAN
Local Area Network
LDPC
Low Density Parity Check
LDR
Low Data Rate
LED
Light Emitting Diode
LF
Low Frequency
LLID
Ethernet Logical Link Identifier
LOF
Loss Of Frame
LoS
Line of Sight
LOS
Loss Of Signal
LSB
Least Significant Bit
LTE
Long Term Evolution (mobile telephone standard)
LV
Low Voltage
MAC
Medium Access Control
MAN
Metro Area Network
MBMS-GW
Multimedia Broadcast Multicast Service Gateway
MBR
Maximum Bit Rate
MBSFN
Multicast Broadcast Single Frequency Network
MCCA
MCF Controlled Channel Access
MCE
Multicell/Multicast Coordination Entity
MCF
Mesh Coordination Function
M-CMTS
Modular CMTS
MCS
Modulation and Coding Scheme
MEF
Metro Ethernet Forum
MELT
Metallic line test
MF
Medium Frequency
MF-TDMA
Multi-Frequency Time Division Multiple Access
MIB
Management Information Base
MIMO
Multiple Input Multiple Out
MLB
Mobility Load Balancing
MLME
MAC Layer Management Entity
MME
Mobility Management Entity
MMSE
Minimum Mean Squared Error
MoCA
Multimedia over Coax Alliance
Modem
Modulator/Demodulator, a transceiver
MPCPDU
Multi-Point Control Protocol PDU
MPDU
MAC Protocol Data Unit
MPEG
Motion Picture Experts Group video compression standards
MRC
Maximal Ratio Combining
MRO
Mobility Robustness Optimization
MSB
Most Significant Bit
MSC
Mobile Switching Center
MSDU
MAC Service Data Unit
MSO
Multiple System Operator (cable network operator)
MTA
Multimedia Terminal Adapter
MTL
Multi-Conductor Transmission Line
MU-MIMO
Multi-user Multiple Input Multiple Output
MV
Medium Voltage
NACK
Negative Acknowledgement
NAS
Non-Access Stratum
NAV
Network Allocation Vector
NB
Narrow Band
NE
Network Element
NEXT
near end crosstalk
NG-PON
FSAN/ITU-T Next Generation PON protocol
NI
Network Interface
NID
Network Interface Device
NMS
Network Management System
Node-B
Base Station in a third generation cellular system
nrt-PS
Non-real-time Poling Service (DOCSIS)
NRZ
Non-Return to Zero line code
NSR
Non-Status Reporting
NTU
Network Termination Units
OAM
Operations, Administration and Maintenance
OAM&P
Operations, Administration, Maintenance and Provisioning
OBSAI
Open Base Station Architecture Initiative
ODN
Optical Distribution Network
OE
Optical to Electrical signal conversion
OEO
Optical to Electrical to Optical signal conversion (repeater)
OFDM
Orthogonal Frequency Division Multiplexing
OFDMA
Orthogonal Frequency Division Multiple Access
OLT
Optical Line Terminal
OLU
Optical Line Unit
OMCC
ONU Management and Control Channel
OMCI
ONU Management and Control Interface
ONT
Optical Network Terminal
ONU
Optical Network Unit
OTN
Optical Transport Network (ITU-T G.709)
OVSF
Orthogonal Variable Spreading Factor
PAM
Pulse Amplitude Modulation
PAP
Priority Action Plan
PBCH
Physical Broadcast Channel
PBR
Prioritized Bit Rate
PCB
Physical layer Control Block
PCC
Primary Component Carrier
PCCH
Paging Control Channel
PCCPCH
Primary Common Control Physical Channel
PCF
Point Coordination Function
PCFICH
Physical Control Format Indicator Channel
PCH
Paging Channel
PCI
Pre-coder Indicator
PCMM
Packet Cable Multi-Media protocol
PCRF
Policy and Charging Rules Function
PDCCH
Physical Downlink Control Channel
PDCP
Packet Data Convergence Protocol
PDFA
Praseodymium Doped Fiber Amplifier
PDN
Packet Data Network
PDN
Premises Distribution Network
PDSCH
Physical Downlink Shared Channel
PDU
Protocol Data Unit
PEIN
Prolonged Electrical Impulse Noise
PF
Proportionally Fair
P-GW
PDN Gateway
PHEV
Plug-in (Hybrid) Electric Vehicles
PHICH
Physical HARQ Indicator Channel
PHS
Payload Header Suppression
PHY
Physical Layer
PIFS
PCF Inter-Frame Spacing
PIN
Photo diode constructed with P-type, Intrinsic, and N-type semiconductor regions
PL
Power Line
PLC
Power Line Communications
PLCP
Physical Layer Convergence Procedure
PLI
Payload Length Indicator
PLO
Physical Layer Overhead
PLOAM
Physical Layer OAM
PMCH
Physical Multicast Channel
PMD
Physical Medium Dependent sublayer
PMI
Precoding Matrix Indicator
PMS-TC
Physical media specific transmission convergence sublayer
PON
Passive Optical Network
POTS
Plain Old Telephone Service
PRACH
Physical Random Access Channel
PRB
Physical Resource Block
PRIME
Powerline Related Intelligent Metering
PS
Packet Switched
PSB
Physical Layer Synchronization Block
PSD
Power Spectral Density
PSS
Primary Synchronization Signal
PSTN
Public Switched Telephone Network
PTI
Payload Type Indicator
PTP
Precision Timing Protocol
PUCCH
Physical Uplink Control Channel
PUSCH
Physical Uplink Shared Channel
QAM
Quadrature Amplitude Modulation
QCI
QoS Class Identifier
QoS
Quality of Service
RACH
Random Access Channel
RAN
Radio Access Network
RAT
Radio Access Technology
RB
Resource Block
RCS
Ripple Carrier Signaling
RDI
Remote Defect Indication
RE
Resource Element
REIN
Repetitive Electrical Impulse Noise
RF
Radio Frequency
RFI
Radio Frequency Interference
RFoG
Radio Frequency over Glass
RI
Rank Indicator
RIT
Radio Interface Technology
RLC
Radio Link Control
RMS-DB
Root Mean Square - Delay Spread
RNC
Radio Network Controller
RoF
Radio over Fiber
RoHC
Robust Header Compression
R-ONU
RFoG Optical Network Unit
RP
Repeater
RP
Reception Point
RRC
Radio Resource Control
RRH
Remote Radio Head
RS
Reed Solomon
RSOA
Reflective Semiconductor Optical Amplifier
RT
Remote Terminal
RTD
Round Trip Delay
rt-PS
Real-time Poling Service (DOCSIS)
RTS
Request-to-send
RTT
Round Trip Time
SA
System Architecture
SAE
Society of Automotive Engineers
SAI
Serving Area Interface
SCADA
Supervisory Control and Data Acquisition
SCB
Single Copy Broadcast Ethernet frame
SCC
Secondary Component Carrier
SCCPCH
Secondary Common Control Physical Channel
SC-FDMA
Single-Carrier Frequency Division Multiple Access
SCH
Synchronization Channel
SCTE
Society of Cable Telecommunications Engineers
SDF
Service Data Flow
SDO
Standard Development Organization
SDU
Service Data Unit
SELT
Single Ended Line Test
SES
Severely Error Seconds
SF
DOCSIS Service Flow
SFBC
Space Frequency Block Coding
SFD
Ethernet Start of Frame Delimiter
SGSN
Serving GPRS Support Node
S-GW
Serving Gateway
SHDSL
Symmetric High bit rate Digital Subscriber Line, ITU-T G.991.2
SHINE
Short High amplitude Impulse Noise Event
SID
Service Identifier
SIEPON
Standard for Service Interoperability in Ethernet Passive Optical Networks
SIFS
Short Inter-Frame Spacing
SIM
Subscriber Identity Module
SINR
Signal-to-Interference-and-Noise Ratio
SIR
Signal-to-Interference Ratio
SLA
Service Level Agreement
SLF
Super Low Frequency
SMB
Small or Medium sized Business
SNMP
Simple Network Management Protocol
SNR
Signal to Noise Ratio
SOA
Semiconductor Optical Amplifier
SON
Self-Optimizing Network
S-ONU
DPoE Standalone ONU
SPS
Semi-Persistent Scheduling
SR
Status Reporting
SR
Scheduling Request
SRS
Sounding Reference Signal
S-SCMA
Synchronous CDMA (used with DOCSIS)
SSID
Service Set Identifier
SSS
Secondary Synchronization Signal
STA
Station
STB
Set-Top Box
STBC
Space Time Block Coding
STM
Synchronous Transfer Mode
SU-MIMO
Single-user Multiple Input Multiple Output
S-VID
Service VLAN Identifier (Ethernet)
T1
Repeatered 1.544 Mbit/s transmission line using Alternate Mark Inversion coding
T1E1.4
United States DSL standards committee now called COAST-NAI
TC
Transmission Convergence
TCM
Time Compression Multiplexing
TCM
Trellis Code Modulation
T-CONT
G-PON Transmission Container
TCP
Transmission Control Protocol
TC-PAM
Trellis Coded Pulse Amplitude Modulation
TDD
Time Division Duplexing
TDFA
Thulium Doped Fiber Amplifier
TDM
Time Division Multiplexing
TDMA
Time Division Multiple Access
TD-SCDMA
Time Division Synchronous Code Division Multiple Access
TFCI
Transport Format Combination Indicator
TFT
Traffic Flow Template
TFTP
Trivial File Transfer Protocol
TG
Task Group
TIA
Transimpedance Amplifier
TL
Transmission Line
TLV
Type-Length-Value field
TM
Transparent Mode
TM
Transmission Mode
ToD
Time of Day
TOS
Type of Service
TP
Transmission Point
TPC
Transmit Power Control
TR-069
Broadband Forum standard for remote management of CPE
TPS-TC
Transport protocol specific transmission convergence sublayer
TTI
Transmission Time Interval
TWACS
Two-Way Automatic Communications System
TWDM
Concurrent time and wavelength division multiplexing
UCD
DOCSIS Upstream Channel Descriptor
UE
User Equipment
UGS
Unsolicited Grant Service (DOCSIS)
UGS-AD
Unsolicited Grant Service with Activity Detection (DOCSIS)
UL
Uplink
ULF
Ultra Low Frequency
UL-SCH
Uplink Shared Channel
UM
Unacknowledged Mode
UMTS
Universal Mobile Telecommunication System
UNB
Ultra Narrowband
UNI
User-Network Interface
U-NII
Unlicensed National Information Infrastructure
UPBO
Upstream Power Back Off
Upstream
Data flowing from the customer
UTRAN
UMTS Terrestrial Radio Access Network
VBR
Variable Bit Rate
vCM
virtual Cable Modem
VCSEL
Vertical-Cavity Surface-Emitting Laser
VDSL1
Very high bit rate Digital Subscriber Line 1, ITU-T G.993.1
VDSL2
Very high bit rate Digital Subscriber Line 2, ITU-T G.993.2
VID
VLAN Identifier
VLAN
Ethernet Virtual LAN
VLF
Very Low Frequency
VoIP
Voice over Internet Protocol
VoLTE
Voice over Long Term Evolution
VSAT
Very Small Aperture Terminal
WAN
Wide Area Network
WARC
World Administrative Radio Conference
WBF
Wavelength Blocking Filter
W-CDMA
Wideband Code Division Multiple Access
WDM
Wavelength Division Multiplexing
WDMA
Wavelength Division Multiple Access
WG
Working Group
WiMAX
A fourth generation cellular standard based on OFDM/OFDMA
WLAN
Wireless Local Area Network
WSD
White-Space Device
XGEM
XG-PON Encapsulation Method
XG-PON
FSAN/ITU-T 10 Gbit/s PON protocol specified in the ITU-T G.987 series
XGTC
XG-PON Transmission Convergence
In the mid-1990s, there were many doubts about the future of broadband access. No one was sure if the mass market needed or wanted more than 100 kbit/s; what applications would drive that need; what broadband access would cost to deploy and operate; what customers were willing to pay; whether the technology could provide reliable service in the real world; or which access technology would “win.” Government regulation in many countries made it unclear if investment in broadband would yield profits. It seemed that broadband access would be available only to wealthy businesses. Fortunately, there were some people who had a vision of a broadband world and who also had the faith to carry on despite the doubts.
We now live in a world where broadband access is the norm and households without it are the exception. No one asks today why the average household would need broadband access. The answer is obvious: we need internet access, with its ever-growing number of applications, and VOD (video on demand). With more than 600 million customers connected to broadband networks, no one asks if the technology works or whether it can meet the customer's willingness to pay.
Furthermore, a growing application of broadband access is the support of femtocells, and small cells in general. Resorting to small cells has today become the most promising trend pursued for increasing wireless spectral efficiency, and the key to its success is the availability of a high capacity wired line to the home. Also, a growing fraction of cellular data is today generated indoors. In addition, it has become clear that no single broadband access technology will win the entire market, and that the market shares of the different technologies will change over time.
Each access technology has its strengths and weaknesses. A common constraint is that we can have it fast, low cost, and everywhere – but not all at the same time. In many cases, the choice of broadband access technology is driven by the legacy network infrastructure of the network provider. In other cases, national regulatory considerations are a significant factor. As a result, each access technology has its areas of dominance in terms of geography, applications, and political domains.
The book is divided into three sections:
The chapters in the first section of the book cover technologies and standard protocols for broadband access over fiber-based access networks.
The chapters in the second section cover technologies and standards associated with non-fiber, non-wireless broadband access.
The chapters in the final section of the book address wireless broadband access technology and standards. Some of these technologies have been widely deployed, while others are anticipated to see deployment soon.
The traditional access network consisted of point-to-point wireline connections between telephone subscribers and an electronic multiplexing or switching system. The early access network used a dedicated pair of wires (referred to as a copper line or “loop”) between the subscriber and the central office (CO) switch.1 As the cost of multiplexing technology decreased, it became more economical in many cases to connect subscribers to a remotely located terminal. This remote terminal (RT) would multiplex calls from multiple subscribers onto a smaller number of wires for the connection to the CO. Network cost was reduced by having far fewer pairs of wires from the CO to the remote areas. As the technology evolved from analog frequency domain multiplexing (FDM) to digital time domain multiplexing (TDM), the RT systems became known as digital loop carrier (DLC) systems.
Data access to the telephone network began with the introduction of voiceband modems that could transmit the data as a modulated signal within the nominally 4 kHz voiceband pass-band frequency. The shorter lines (loops) allowed by DLCs made increasingly efficient modulation technologies practical. However, as explained in Appendix 1.A, the maximum data capacity of voiceband modems was limited to 33.6 kbit/s, or 56 kbit/s under special circumstances. Modems and their evolution are also discussed briefly in Appendix 1.A.
As a result, out-of-band technologies were introduced that transmitted signals over the copper line at frequencies outside the voiceband. Since these technologies sent digital information in the out-of-band signals, they became known collectively as digital subscriber line (DSL) technology. DSL is discussed further in Section 1.3 and Chapter 7–10.
Since the subscriber lines are implemented with twisted wire pairs, with multiple lines sharing the same cable without being shielded from each other, there are limits on the bandwidth that is achievable with DSL. For this reason, network providers became interested in alternatives to the subscriber line for providing broadband access. The three main contending technologies are coaxial cable, fiber optic cable, and wireless radio frequency connections. Each of these technologies is reviewed in later chapters of this book.
Coaxial cable networks were deployed by community access cable television (CATV) companies to provide broadcast video distribution. Due to the high bandwidth capabilities of coaxial cables, they had the potential for offering broadband services to their subscribers. In order to offer broadband data services, CATV companies evolved their networks to support upstream data transmission, and introduced fiber optic cables for higher performance in the feeder portion of their networks. As discussed below and in Chapter 11, coaxial networks have their own challenges as well as advantages.
Telephone network providers responded to the potential broadband advantages of the CATV companies by deploying additional fiber in their access networks. Telephone companies have deployed fiber directly to each subscriber's premises in some areas. Others are deploying fiber to terminals near enough to the subscribers' premises that broadband services can be provided by the latest very high-speed DSL technologies. The most attractive aspect to fiber is its virtually unlimited bandwidth capability. The primary drawback has been the relatively high cost of the network and its associated optical components.
Wireless access had not originally been a significant contending technology for residential broadband access. However, as wireless mobile networks have become widely deployed, and new technologies and protocols have been developed, wireless broadband access has become increasingly important. It is especially attractive in regions that lacked a legacy wireline infrastructure capable of evolution to broadband services. Examples of such regions include developing nations and rural areas. It also offers the very significant advantage of allowing mobile, ubiquitous service rather than being restricted to service at the subscriber's premises.
Since a limited amount of spectrum is available for use in broadband services, the networks to support it have become increasingly complex. For spectrum efficiency, wireless networks use grids of antenna, where each subscriber only needs enough signal power to reach the nearest antenna. The region covered by each antenna is referred to as a cell. The result is that the same frequencies can be used by subscribers in non-adjacent cells, since their signals should not propagate far enough to interfere with each other. The signal formats have been optimized in the latest protocols to approach the Shannon limit for data bits transmitted per Hertz of transmission channel bandwidth. Capacity is further increased by re-use of the spectrum through smaller cells and smart antenna technologies. Both add cost, and radio signals are always more vulnerable to various types of interference than wireline technologies. Wireless technologies are discussed further in Section 1.6 below, and in detail in Chapter 14–17.
DSL operates over a copper line at frequencies outside the voiceband, sending digital data directly from the subscriber, and thus avoiding the need for an analog to digital conversion. Since the telephone lines were designed to provide good quality for voiceband signals, they are often not particularly well suited for higher rate data signals. Reflections become a significant problem in the electrical domain at rates beyond the voiceband. One of the worst sources of reflections in North American networks is bridge taps. When the feeder cables are installed from the CO into the loop area, they go to splice boxes where the wires going to the subscribers are connected. When service is disconnected to a subscriber (e.g., due to the homeowner moving), a second pair of wires may be connected to the feeder cable to serve a different subscriber without removing the other line. The result is a bridge tap, and it is possible to have bridge taps at more than one location along the connection to a subscriber. The unterminated end of the unused line(s) causes electrical reflections of the DSL signals, and these reflections can cause destructive interference for certain frequencies (any impedance mismatch along the copper connection to the CO to the subscriber can cause harmful reflections, but the bridge taps are especially bad).
The first widely deployed services using a digital subscriber line were the Digital Data Service (DDS) from AT&T. DDS used baseband signals over the line and offered data rates including 2400, 4800 and 9600 bits/s, and 56 kbit/s. The lower rate signals were sometimes converted to analog signals at the CO and then mapped into a voiceband channel, thus avoiding any noise or distortion from the subscriber line. DDS required the end-to-end service be synchronized to a common atomic clock. DDS circuits also usually required that the line be groomed to remove impairments such as bridge taps. While DDS circuits were very valuable for some customers (e.g., banks using them for connections to ATM machines), they were too expensive to deploy to residential subscribers or even to many business subscribers.
The first serious attempt to provide higher data rates to subscribers was the basic rate interface of the Integrated Services Digital Network (ISDN-BRI). ISDN-BRI used baseband signals2 over the subscriber line to offer bidirectional data rates of 144 kbit/s. ISDN-BRI was designed to operate over most subscriber lines of up to 18 000 feet without having to remove impairments such as bridge taps from the lines. The 144 kbit/s signal was typically divided into two 64 kbit/s bearer (B) channels and a 16 kbit/s data (D) channel. The B channels could be used for voice or data, while the D channel carried the connection signaling information, with its leftover bandwidth available to carry subscriber data packets. It was also possible to merge the two B channels or merge the Bs and D channel into a single 144 kbit/s channel. The cost of ISDN-BRI was relatively expensive, however, and there were no driving subscriber applications to generate high demand. ISDN also required that the connection signaling protocol be processed by the CO switch, which meant a major upgrade to the switches. By the time that Internet connectivity became a driving application, much higher rates were practical for DSL.3 In effect, ISDN BRI provided too little bandwidth, too late, with too much network complexity.4
DSL modems that were dedicated to data services began to be widely deployed instead of ISDN-BRI. Initially, there were two broad categories of DSL. The first was a high speed DSL (HDSL) that provided bidirectional symmetric service at half the DS1 rate over a single pair,5 or symmetric full DS1 rate over two pairs (half on each pair). Although it would seem that HDSL had no advantage over T16 service, which also uses two pairs, HDSL was capable of operating over much longer line lengths than T1, and it could do so without requiring repeaters. The total cost of HDSL was less than half of T1 lines, mainly due to eliminating most of the labor needed to install repeaters and remove bridged taps. It became common for carriers to use HDSL as the primary technology for providing DS1 connections to business customers. The current generation of HDSL is HDSL2, which allows bidirectional symmetric transmission of up to 2.048 Mbit/s payloads over a single wire pair.
The second category is the DSL lines optimized for residential subscriber access. The first generation was called ADSL (asymmetric DSL) due to its use of asymmetric data rates in the upstream and downstream directions. Since residential subscriber are typically downloading more information than they are providing to the network, they typically require much higher data rates from the network (downstream) than they do for upstream. This asymmetry in the desired data rates per direction was exploited to achieve the higher downstream rates. The service rate for ADSL is affected by several factors, but line length is the primary one. Over the past 25 years, telephone companies have tried to limit the line lengths to 12 000 feet.7 Rates of 768 kbit/s downstream with 384 kbit/s upstream are possible over most of these lines. The actual rate is often determined adaptively as the system uses feedback to determine the frequency response of the line. In addition to higher data rates, another advantage of these DSL systems over ISDN-BRI was that they left the voiceband frequencies available for voice signals. This allowed analog POTS (Plain Old Telephone Service) signals to “ride underneath” the DSL data in its native format, which kept the voice and data signals separate within the network and allowed subscribers to use their existing telephone sets without conversion to digital signals at the subscriber premises.
ADSL rates and signal formats have been standardized by the ADSL Forum (now the Broadband Forum), by T1E1 (now ATIS COAST-NAI) and by the ITU-T SG15. SG15 is the primary body developing the current generation of DSL standards. The latest generation of ADSL is specified in the ITU-T G.992.5 standard for ADSL2plus which enables up to 20 Mb/s, with 12 Mb/s possible at 3000 feet.
Video delivery will require rates of 10–50 Mbit/s, depending on the service. For these rates, very high-speed DSL (VDSL) is required. VDSL requires lines lengths limited to 5000 feet. ITU-T SG15 has developed the VDSL2 standard, whose specifications are provided in ITU-T G.993.2 which enables rates up to 100 Mb/s upstream and downstream with 25 Mb/s downstream possible at 3000 feet. The ITU-T is developing the G.fast standard which promises to achieve bit rates up to 1 Gb/s over short copper lines.
Both ADSL2plus and VDSL2 support transmission of packet transport mode (PTM), asynchronous transport mode, and synchronous transport mode (STM). ITU-T G.997.1 specifies management parameters for ADSL2plus and VDSL2.
The first generation of DSL equipment connected DSL modems at the subscriber premises to DSL access multiplexers (DSLAMs) located in the central office. DSLAMs were next deployed in remote locations that were often co-located with DLC RTs. If the DLC RT was served by a SONET fiber connection, the DSLAM traffic would be multiplexed onto the same SONET signal as the DLC voice traffic. One of the challenges of co-locating the DSLAM and RT is that the DSLAMs require much more power per line than DLC equipment. This leads to heat dissipation issues when they shared the same cabinet, which can restrict the number of DSL lines that can be served. The DSLAM is not connected to the RTs backup batteries, however, since there is no requirement to maintain DSL service during a power outage.8
DSL was developed at a time when Asynchronous Transfer Mode (ATM) appeared to the preferred multiplexing technology for next generation networks. ATM provided adaptation techniques to carry a wide variety of packet-oriented data and constant bit rate (CBR) traffic such as voice signals. Hence, ATM was a natural choice for the encapsulation technology over the DSL line and for the multiplexing technology within the DSLAM. ATM allowed some statistical multiplexing for more efficient bandwidth utilization on the trunk from the remote DSLAM to the CO, or within the network.
There are two drawbacks to ATM, however. The first is that it adds at least five bytes of overhead to each 53-byte cell, causing a roughly 10% bandwidth overhead penalty. The bandwidth penalty is sometimes referred to as the ATM “cell tax.” The other drawback to ATM is that it typically uses a rather complex signaling protocol that is overkill for purposes such as carrying connections to the Internet. Since most of the data going over DSL systems uses the Internet Protocol (IP) for Layer 3, it makes sense to use lower layer protocols that are more efficient with IP packets. Consequently, the emerging generation of DSLAMs is IP-based and uses Ethernet for the Layer 2 protocol instead ATM. These are commonly referred to as IP-DSLAMs.