wimax broadband wireless access technology

WIMAX OUTLOOK SERIES BEST SELLER, RESOURCE4BUSINESS, 2005BUSINESS OF WIMAX, J WILEY & SONS, 2005 WIMAX – TAKING WIRELESS TO THE MAX, CRC PRESS, 2005 WIMAX – BROADBAND WIRELESS ACCESS TEC

WIMAX OUTLOOK SERIES BEST SELLER, RESOURCE4BUSINESS, 2005

BUSINESS OF WIMAX, J WILEY & SONS, 2005

WIMAX – TAKING WIRELESS TO THE MAX, CRC PRESS, 2005

WIMAX – BROADBAND WIRELESS ACCESS TECHNOLOGY, IDEA GROUP 2006

C OLUMNIST

WIMAX.COM, WIMAXXED.COM, CONNECTWORLD

“WIMAX: BROADBAND WIRELESS ACCESS

TECHNOLOGY"

Table of Content

Preface 21

Section 1 24

WiMAX - Overview 24

Chapter 1 25

Introduction 25

Broadband Age 27

What is Broadband? 30

Broadband Technologies 34

Broadband Demand 45

Economics of Broadband 50

Broadband Connectivity Solutions 53

Designing Broadband Solution 59

Mobile & Wireless Access 68

Wireless Broadband - The Communications Revolution79

Attraction of Wireless Broadband 80

Need for Wireless Broadband 81

Broadband Wireless Access 82

Broadband Wireless Networks 85

Broadband Wireless Technologies 89

WiMAX - Broadband for Masses 96

Chapter 2 99

WiMAX – The Disruptive Technology 99

Impact of Disruption 102

Technology Life Cycle 105

Disruption 106

Dominant Design 107

Disruption and New Market 108

Innovation for Disruption 109

Technology Strategy 112

Emerging & Established Technologies 113

Technology Uncertainty 114

Technology Adoption 116

Broadband Wireless - Technology Advancements 120

WiMAX – The Biggest Disruption 125

It’s Different 127

WiMAX - Disruptive Capabilities 130

What is WiMAX? 131

Why WiMAX 133

WiMAX Hype or Reality 135

Chapter 3 137

How WiMAX Works 137

Robust Technology 140

Channel Characteristics 141

RF and Hardware Considerations 144

Flexible Tradeoffs 146

WiMAX Networks 147

WiMAX Types 150

Building Blocks of WiMAX 153

WiMAX Base Station 156

Working Mechanism 169

Operational 173

Architecture 173

Network Topology 175

Point to Point 175

Point to Multi Point 176

Mesh 178

Section 2 187

WiMAX - Cutting Edge 187

Chapter 4 188

WiMAX – Specification 188

Basic Profiles 192

Medium Access Control (MAC) Layer 203

Physical (PHY) Layer 225

Mobile WiMAX 228

RF System 234

WiMAX – State of the Art Technologies 237

Learning from The Past 237

Technology of WiMAX 243

Dynamic Burst Mode TDMA MAC 243

Quality of Service 243

Link Adaptation 244

Non Line Of Sight (NLoS) Support 245

Highly Efficient Spectrum Utilization 247

Flexible Channel Bandwidth 250

Smart Antenna Support 251

Error Correction Techniques 256

Power Control 257

Data Security 258

WiMAX Radio 260

Multiplexing Technology 260

Modulating Technology 265

Duplexing Technology 270

WiMAX Silicon 273

System on Chip (SoC) 276

Chapter 6 278

WiMAX Proposition 278

Features of Substance 279

Value Creation 285

Drivers 291

Throughput & Coverage 291

Flexibility & Scalability 292

Cost Effectiveness 294

Emergence of Standards 294

Backing of Intel 296

Challenges 298

RF Interference 298

Infrastructure Placement 299

Roll out Cost 302

Incomplete Standards 302

Chipset Availability 304

Interoperability Testing and Market Feel 304

Competition 311

Wireline 315

Wireless 317

Section 3 332

WiMAX – Roll Out 332

Chapter 7 334

WiMAX Standard 334

Why Standards 334

IEEE 802.16 Standards Family 338

IEEE 802.16 345

Mobile Broadband Wireless Access (MBWA) 361

MBWA Technology Issues 363

Power Consumption Reduction 364

IEEE 802.20 - Alternate MBWA 366

Chapter 8 369

WiMAX TM & IEEE 802.16 370

WiMAX Forum 371

Global Harmonization 374

Why Certification 377

Conformance vs Interoperability 386

Certification Process 387

Conformance Testing 387

Interoperability Testing 389

Abstract Test Suite Process 392

Chapter 9 394

WiMAX Regulation 394

Regulating Broadband 394

Broadband for Unserved 396

Wireless Regulation 398

Regulatory Framework and Convergence 401

Deregulation 404

Spectrum 410

Licensed and Unlicensed Spectrum 412

The Spectrum Picture 423

New Bands of Interest 428

Section 4 430

WiMAX - Planning 430

Chapter 10 431

WiMAX Business 431

WiMAX Markets 433

WiMAX and Demographics 435

WiMAX Applications 438

Metropolitan-Area Networks (MANs) 441

Last Mile High Speed Internet Access or Wireless DSL 444

Backhaul 448

Other Applications 450

WiMAX Business Models 457

Last Mile 458

WiMAX Opportunity 465

Strategy to Succeed 468

Technology Forecasting 470

Service Providers 472

Public Sector 474

Regulators 476

Equipment Vendors 480

Investor 483

Chapter 11 484

WiMAX Deployment 484

WiMax Business Planning 487

Provision of Service 490

Deployment Best Practices 491

Deployment Stages 495

Deployment Type 496

Designing WiMAX Solution 506

System Components 506

WiMAX Network Planning 507

Need for Scalability 513

Hardware Platform 520

Choosing the Best SoC 523

WiBro – The WiMAX Sibling 526

Chapter 12 530

Conclusion & The Way Forward 530

Expectations 532

Early Movers 533

Road Ahead 535

Next Generation Networks 536

What Future Holds 538

IP Multimedia Subsystem (IMS) 548

IMS Definition 548

IMS Applications 552

IP UTRAN 555

4th Generation 555

Appendix 559

Appendix 1 560

Wireless Standards 560

WLAN - Wi-Fi, IEEE 802.11 567

WiFi – Standards 572

Appendix 3 579

WPAN – Bluetooth, Ultra Wideband and ZigBee 579 Appendix 4 590

WWAN - Cellular Technology 590

Appendix 5 599

Proprietary BWA Systems 599

Appendix 6 603

Trends & Projections 603

BIBLIOGRAPHY 610

ABBREVIATIONS AND GLOSSARY 616

ABOUT AUTHOR 660

T ABLE OF F IGURES

Figure 1 - Broadband Evolution 28

Figure 2 - Applications of High Speed Internet 34

Figure 3 - Access Technologies and Speeds 38

Figure 4 - Internet Access Technologies 40

Figure 5 - Broadband Subscribers Projection - USA 46

Figure 6 Residential Broadband Penetration Trends & Forecast -Europe 49

Figure 7 - Total Utility Curve for Broadband 51

Figure 8 - Marginal Utility Curve for Broadband 52

Figure 9 - OSI Model 62

Figure 10 - Voice Service Subscribers - Fixed Vs Mobile 69

Figure 11 - Worldwide Subscriber Base for Wireless Broadband Services 70

Figure 12 - Use of Mobile Data 80

Figure 13 - Wireless Network Types 86

Figure 14 - Various BWA Technology 89

Figure 15 - Cellular Wireless Technology Evolution 92

Figure 17 - Disruptive Technology Performance Curve 102

Figure 18 - Technology Life Cycle 106

Figure 19 - Sustaining and Disruptive Technology Cycle 107

Figure 20 - Sustained Innovations for Disruption 111

Figure 21 - WiMAX Adoption and Acceptance 116

Figure 22 - Technology Adoption Chasm 118

Figure 23 – WiMAX: One Solution for Multiple Needs 140

Figure 24 - WiMAX Wireless Complete Ethernet Solution 141

Figure 25 - WiMAX Coverage With Different SS Types 150

Figure 26 - WiMAX Types 152

Figure 27 - WiMAX PHY Architecture 167

Figure 28 - WiMAX Point to Multi Point Deployment 178

Figure 29 - Mesh Network 179

Figure 30 - Multi-stake Holder Relationships for WiMAX Standard 192

Figure 31 - Scope of WiMAX Specification 193

Figure 32 - Layers of the 802.16 Protocol 197

Figure 33 - 10-66 GHZ TDD Frame for 1mS, 198

Figure 35 - PSDU Transport Stages 208

Figure 36 - Burst FDD - With Scheduling Flexibility 225

Figure 37 - Working of Smart Antennas 254

Figure 38 - Power Control Using Sleep Mode 258

Figure 39 - OFDM Wave Form 260

Figure 40 - OFDM Channel 263

Figure 41 - Adaptive Modulation 268

Figure 42 - Radio on Silicon 273

Figure 43 - WiMAX SoC 276

Figure 44 - Coverage Vs Throughput 291

Figure 45 - Cost Advantage of WiMAX 294

Figure 46 - WiMAX OpEx Break-up 301

Figure 47 – WiMAX Network Coverage Cost Vs Frequency Curves, Rural, Suburban and Urban 307

Figure 48 - Path Length & Capacity Curve for Different Frequency Bands in Line of Sight Deployments 308

Figure 49 - Value Analysis, 3G, WLAN (Wi-Fi) and WiMAX 317

Figure 50 - 3G Time Line 329

Figure 52- WiMAX Standard Evolution 342

Figure 53 - L2.5 Label Routing for 802.16e 366

Figure 54 - WiMAX Forum Defined Interoperability 389

Figure 55 - Certification Process 390

Figure 56 - Abstract Test Suite Development Process 392

Figure 57 - Collaborative Technology Environment 401

Figure 58 - Average Modelled Downlink Capacity for WiMAX in 3.5GHz Band 412

Figure 59 - Global Licensed & Un Licensed Band Allocations 423

Figure 60 - Spectrum Picture for WiMAX 424

Figure 61- WiMAX Applications 438

Figure 62 - Metropolitan-Area Networks (MANs) 440

Figure 63 - Cellular Backhaul 448

Figure 64 - Diverse WiMAX Applications 450

Figure 65 - Personal Broadband 459

Figure 66 - Opportunity for WiMAX 467

Figure 67 - Business Risks of WiMAX 469

Figure 68 - Technology Evaluation 487

Figure 70 - WiMAX Deployment 516

Figure 71 - WiBro Spectrum 526

Figure 72 - WiBro Speed Vs Mobility 527

Figure 73 - WiBro Value Analysis 528

Figure 74 - WiBro Functional Model 529

Figure 75 - WiMAX Future Evolution 536

Figure 76 - Next Generation Network Architecture 543

Figure 77 - Next Generation Network with RAN, PCN and IMS 552

Figure 78 - SIP in VoIP Service 554

Figure 79 - Worldwide Broadband Subscribers - According to Technology Used 604

Figure 80 - Fixed BWA Users – World Wide 605

Figure 81 - WiFi Client Units – World Wide 606

Figure 82 - World Wide WiMAX Subscribers by Standards 607

Figure 83 - World Wide WiMAX Subscribers by Segment 608

Figure 84 - World Wide 802.16a & Proprietary < 11GHz Subscribers & Equipment Revenue 609

T ABLE OF T ABLES Table 1 - Broadband Throughput as a Function of Delivery and Time

45

Table 2 - Features of Wireless Networking Standards 76

Table 3 - Wireless Personal Area Network (WPAN) Technologies 88

Table 4 - Sustaining Technology Vs Disruptive Technology 104

Table 5 - 802.16 MAC Features 164

Table 6 - 802.16 PHY Features 166

Table 7 - Working Mechanism for WiMAX Connection 173

Table 8 - BWA Evolution 242

Table 9 - QoS for WiMAX 282

Table 10 - Spectrum used for Broadband Wireless in the US 310

Table 11 - Present and Future of Broadband Technologies - DSL, Cable, BWA/WiMAX 315

Table 12 - Relationship between IEEE 802.16 and IEEE 802.11 321

Table 13 - Capabilities of WiMAX and various 3 G Technologies .331 Table 14 - Characteristics of Key IEEE 802.16 Standards 338

Table 15 - IEEE 802.16 Family of Standard 345

Table 17 - Comparison between FBWA and MBWA 356

Table 18 - Comparison between IEEE 802.20 and IEEE 802.16e 368

Table 19- WiMAX Forum Mission & Principles 374

Table 20 - Bands and frequencies available for WiMAX 386

Table 21 - Key Advantages & Disadvantages - Converged Regulators 404

Table 22 - Regulatory Environment for Wireless - Europe & US 410

Table 23 - List of First Stage System Profiles 414

Table 24- Matrix of Opportunity by Demography 466

Table 25 - Matrix of Opportunity by Sector 467

Table 26 - WiMAX Multiple Antenna Schemes 512

Table 27 - IMS Evolution 551

Table 28 - WPAN - Technology Comparison 589

Preface

Modern disruptive technologies are revolutionising the way we work, play,and interact It won’t be an exaggeration if we suggest these technologiesare altering the way we live More interesting to note is that with everypassing day these disruptions are becoming more rapid This trend hascreated new competitive threats as well as new opportunities in each walk

of our lives

One such technology, which will have profound impact on future of ourworld, is WiMAX This groundbreaking development in Broadband WirelessAccess technology landscape is an evolving standard for point-to-multipointwireless networking, works for the "last mile" in the same way that WiFi

"hotspots" work for the last one hundred feet of networking

Think of the possibilities that this affordable broadband wireless accesstechnology offer to wide range of users like you and me Theseadvancements on WiMAX technology front can save life of millions ofpeople living in remote underdeveloped part of the globe by providingremote health care services, emergency or distress information regardingpossible typhoons, floods or may be the Tsunamis An under served poorkid living in sub-Sahara can read details of latest experiments in spacescience or biotechnology conducted in California or Oxford

Potential of WiMAX is phenomenal.

“WiMAX – Broadband Wireless Access Technology” is a book which is

a step in the direction to demystify WiMAX The key idea behind the book is

“To pin down the technical details that make WiMAX actually work”

In WiMAX – Broadband Wireless Access Technology, Deepak Pareek an

expert in the field dissects critical issues of compatibility, internetworking,standardization and certification, providing audience an in-depthunderstanding of the field

The book is divided in four sections each covering an important aspect ofsubject The centrepiece of the book is in-depth exploration of the

“Disruptive Technology Innovations of WiMAX, WiMAX Deployment Planningand Successful Solution Strategies for all the stake holders”

SECTION 1 - WiMAX - Overview

WiMAX, or the IEEE 802.16 standard for broadband wireless access, isincreasingly gaining in popularity as a technology with significant marketpotential This section as the name suggest provides an overview of WiMAXwhile putting forward concept of “Disruptive Technology”

SECTION 2 - WiMAX - Cutting Edge

WiMAX is not one technology but a aggregation of many technologyinnovations bound together by IEEE 802.16 standards effort This section,

associated characteristics

SECTION 3 - WiMAX – Roll Out

This section provides understanding about issues related to WiMAXdeployment, which includes discussions about standards, certification andregulation

SECTION 4 - WiMAX - Planning

This section, the last one of this book, deals with some of the majoraspects of planning a successful WiMAX solution The section deals withthree major areas of business planning, deployment planning and futurestrategy

The book also incorporates some detailed readings on different topicswhich have been touched upon in main text but were not covered for sake

of larger audience Annexure provides an overview of these topics

WiMAX – Bigger than the Biggest Disruption

S ECTION 1

WiMAX - Overview

WiMAX, or the IEEE 802.16 standard for broadband wireless access, isincreasingly gaining in popularity as a technology with significant marketpotential This section as the name suggest provides an overview of WiMAXwhile putting forward concept of “Disruptive Technology” The sectionconsists of three chapters

Chapter 1 – Introduction

This chapter provides background information on developments in area ofBroadband, Wireless and Mobile Broadband including WiMAX

Chapter 2 – WiMAX: The Disruptive Technology

This chapter, as evident by the name, provides an in-depth understandingabout factors making WiMAX a disruption and discusses in detail theconcept of “Technology Disruption”

Chapter 3 – How WiMAX Works

This chapter takes a close look at all the pieces of WiMAX puzzle, includingits component i.e Base Station, Subscriber Station and Backhaul It alsodiscusses the WiMAX architecture and provides insight about variousnetwork related issues including Network Topologies The PHY and MAC

to millions of people across the globe, creating new choices andopportunities in some of the most vital realms of human endeavour

Modern societies are currently undergoing a number of fundamentaltransformations caused by the growing impact of the new ICTs on allaspects of human life But this revolution brought about by the newtechnologies has to confront a major challenge, namely the extremedisparities of access between the industrialized countries and thedeveloping countries and those in transition, as well as within societiesthemselves

Even though there has been a substantial increase in telecom investmentnot to forget technology advancements in the past decade, there are stillenormous gaps in accessibility There is still an average tele-density indecimals in the poorest countries while in some advance countries it is

non-urban areas

Affordable access, connectivity, and the skills to utilise increasinglyadvanced but essential services remain the central public interest issues inthe area of information and communication technologies across the globe.This is true for all countries, but particularly for developing countries

There are many reasons behind polarization of today's knowledge society

on basis of access to connectivity hence information Some of the vitalissues extensively responsible for “digital divide1” across the globe are lack

of resources, scarce infrastructure, widespread illiteracy, inadequatetechnology, biased policies, apathetic governance, political instability anddeep rooted corruption Technology though is considered undeniablyimportant, in comparison with other causes it is rated less important thanpolicy, funding, and geo-political issues to name a few

All these issues are interrelated and have technology as insignificantcomponent But in recent past advancement of information andcommunication technology had revolutionary impact on these obstacles,

1 The concept of the “digital divide” expresses the gap in access to

information resources in some countries compared with those with of-the-art networks: telephone, radio, TV, Internet, satellite, in short,anything that can be classed as Information and CommunicationTechnologies (ICT) Thus the digital divide expresses the difference infacilities for people to communicate, relative to their geographic location,their living standard and their level of education Ultimately it is anindicator of a country’s economic and social situation

state-concurrent technological innovations, coined as Disruptive Technologies,underpinned by a number of externalities (network externalities,knowledge-sharing effects, innovative business modelling) neverexperienced in the past

BROADBAND AGE

The history of modern-day communications technology can be said to havestarted when Samuel Morse invented the wireline telegraph in 1832.However, it was Alexander Graham Bell's invention of the telephone, in

1874, that led to the development of our present day communicationstechnology The former had simply created a way for humans to extendtheir ability to transfer information – instantly – over long distances, whilelater gave the ability to have the most personal and intimate form ofcommunication over distances – the use of our voices

The concept of the telephone was so strong that most communicationtechnology during the past century was developed to support an efficientvoice communication network From 1874 to 1980, communicationnetworks around the world were constructed to facilitate the efficient andeconomical transmission of voice conversations Multiplexing and digitaltransmission systems were developed to "cram" more voice conversationsinto the existing copper wire communication facilities

The Internet, first developed in 1973 initiated a profound change in thefuture development of communications networks and technologies.Originally called the Arpanet, which linked several Universities, andresearch laboratories it evolved into the World Wide Web (WWW) The

information processing, data sharing and data storage In the ‘90s, theInternet was even more revolutionary in terms of communications andfurthering the progress of data sharing, from the personal level to theglobal enterprise level

It wasn't until 2004 that major telecommunication carriers announced theneed to develop, and support, a network designed for the purpose oftransporting high-speed digital data instead of voice centric networks.While the 1970s and 1980s will be remembered as the “Information Age,”and the 1990s will undoubtedly be singled out in history as the beginning

of the “Internet Age,” the first decades of the 21st Century may becomethe “Broadband Age”

Today, broadband sources such as fibre-optic, wireless access and cablemodems provide very high-speed access to information and media of alltypes via corporate networks and the World Wide Web, creating an

“always-on” environment The result will eventually be a widespreadconvergence of entertainment, telephony and computerized information:data, voice and video, delivered to a rapidly evolving array of Internetappliances, PDAs, wireless devices (including cellular telephones) anddesktop computers

Broadband access networks are much faster than traditional dial-upconnections Broadband networks are fast enough to deliver a variety of

video) and, most important, voice.

What is Broadband?

There are various definitions of broadband, and it is worth noting thatworking definitions have changed and are changing with both time andplace A simple notion is anything perceptibly better than a basic ISDN line.This implies a rate around or exceeding 256 kbps, although customers mayaccept less if this is the best available to them A common current

understanding is “a service that is always on, and can scale up to at least 2

Mbps”.

Some broadband access technology platforms have a dedicated channel toeach user (for example ADSL and fibre-to-the-user), while others have ashared channel that goes to many users A feature of this second type ofsystem is contention for the bandwidth, because it is shared In this type ofsystem the maximum instantaneous bandwidth obtainable exceeds by alarge margin the average bandwidth a user enjoys

Irrespective of however it is defined and technology platform it use, what isimportant and hence useful to examine, is the user services that becomepossible with “broadband” As it is these services, and not theoreticaltechnical definitions, that drive consumer demand the stress must always

be on applications

and each has its own peculiar technical requirements While for onethroughput is vital then for another low latency (this is time delay torespond, and is typical of satellite links because of the long distance thesignals must travel) is critical Nonetheless, it possible in broad terms toidentify a trail of application types such that the most basic broadbandservice supports only the first while the highest offering supports them all.

In the interests of cost, availability and financial realism, a user group or acommunity may decide what it can afford and what it cannot Some of themost prevalent applications and services are

Type 1: Messaging Services

These include simple e-mail, instant text messaging, remote login, simpleweb and Internet access, electronic shopping and business, electronicgovernment and chat These services can operate at the lowest bandwidthssuch as 256 or 512 kbps, although they are considerably more convenientand enjoyable when enriched by higher bandwidths Most users receivemore data than they send, so these services are compatible withasymmetric broadband (higher downstream than upstream capacity).These services can tolerate latency

Type 2: Large File Transfer Services

quantities of data, perhaps 100’s kilobytes or megabytes as opposed to thetens of kilobytes envisaged for simple messaging They may be extendedsimple messaging services, for example rich-content Internet surfing,electronic catalogue shopping, remote healthcare, home working, remoteworking and business virtual private networks (VPNs) Large-scale filetransfer services include downloading of games, software, educationalmaterial, films and other entertainment content These services ideallyrequire 1-2 Mbps or higher, if the user is not to be kept waiting too long.

As with Type 1, Type 2 services are compatible with asymmetric links andcan tolerate latency

Type 3: Unidirectional Real Time Services

These are mainly broadcast services such as audio and video streaming,and radio and television broadcasting These services typically require high(at least 1.5 Mbps for video) or very high bandwidths, and are inherentlyasymmetric They can tolerate high latency, as the data flow is one wayonly

Type 4: Interactive Real Time Messaging Services

These messaging services operate between users who are interacting onewith another, such bi-directional real time services include, video-conferencing, interactive video, interactive gaming, integrated business

over a broadband link and wide area networks These services ideallyrequire 1-2 Mbps or higher, need to be symmetric and cannot toleratelatency.

The promises of broadband technologies have generated much interest allaround However in reality, a lot needs to be done for broadband to deliver

as per its promises The key is to identify ways to unleash the potential ofbroadband networks

Today's broadband solutions are quite complex and require semiconductormanufacturers to integrate a wide variety of innovative technologies tooffer low-power, cost-effective system solutions that address the needs oforiginal equipment manufacturers (OEMs), service providers, and endusers This tutorial provides an overview of various broadbandinfrastructure, access, and home networking technologies and examinesthe essential technology building blocks required to deliver end-to-endbroadband connectivity from the infrastructure to endpoint devices

Broadband Technologies

There are multiple transmission media or technologies that can be used toprovide broadband access Each technology has its respective advantagesand disadvantages, and will likely compete with each other based onperformance, price, quality of service, geography, user friendliness, andother factors

Cable and DSL are currently the most widely used technologies forproviding broadband access Both require the modification of an existingphysical infrastructure that is already connected to the home

The same cable network that currently provides television service toconsumers is being modified to provide broadband access with maximumdownload speeds as much as 6 Mbps As an alternative to existing copperphone wires, cable companies have been providing broadband access usingtheir cable plant to carry data and voice services in addition to traditionalvideo services

A cable-modem termination system (CMTS) communicates with cablemodems located at the customer premises to provide broadband accessservices The cable modem typically provides an Ethernet interface to a PC

or to a small router when multiple PCs are connected However, networksharing has also led to security concerns and fears that hackers might beable to eavesdrop on a neighbour’s Internet connection

Today's cable networks generally deliver data with download speedsroughly between 500 kbps and 6 Mbps and upstream speeds of 128 kbps

As users share cable networks, access speeds can decrease when manycustomers are sharing bandwidth at the same time

Newer-generation cable-modem technologies will significantly increase theavailable bandwidth to further enable interactive applications such asvideoconferencing and high-end on-line video Internet protocol (IP)telephony is one of the services that can be delivered over coaxial cable

that, to date, have been the domain of the telephone companies

Digital Subscriber Line (DSL) & ADSL

DSL is a modem technology that converts existing copper telephone linesinto two-way high-speed data conduits Data transmission speeds typicallyrange up to 3 Mbps for downloading and 768 kbps for uploading Speedscan depend on the condition of the telephone wire and the distancebetween the home and the telephone company’s central office

DSL technology is a copper-loop transmission technology for transmittinghigh-speed data over ordinary telephone wires A DSL modem is installed

at the customer premises and at the central office (CO) Different variants

of DSL exist to address different technology trade-offs that can be maderegarding different network environments and applications One of the keytrade-offs is distance (referred to as reach) from the CO and data rate Asymmetrical DSL, or ADSL, is primarily used for residential services ADSLtakes advantage of the fact that there is more cross talk interference at the

CO end of a copper pair than at the subscriber end due to the largebundles of cabling entering the CO ADSL can provide data rates up to 8Mbps from the network to the subscriber direction, and up to 1 Mbps fromthe subscriber to the network direction The asymmetry of ADSL works well

in the network to user direction

As ADSL uses frequencies much higher than those used for voicecommunication, both voice and data can be sent over the same telephoneline Thus, customers can talk on their telephone while they are online, andvoice service will continue even if the ADSL service goes down Like cablebroadband technology, an ADSL line is “always on” with no dial-uprequired Unlike cable, however, ADSL has the advantage of beingunshared between the customer and the central office Thus, datatransmission speeds will not necessarily decrease during periods of heavylocal Internet use

A disadvantage relative to cable is that ADSL deployment is constrained bythe distance between the subscriber and the central office ADSLtechnology over a copper wire only works within 18,000 feet (about threemiles) of a central office facility However, providers are deployingtechnology to further increase deployment range

Symmetrical DSL, or SDSL, is a cost-effective solution for small andmedium enterprises, offering a competitive alternative to T1 and E1 lines.The International Telecommunication Union-TelecommunicationsStandardization Sector (ITU-T) standard G.991.2, also known as G.shdsl, is

a replacement standard for proprietary SDSL G.shdsl offers data ratesfrom 192 kbps to 2.3 Mbps while providing a 30% longer reach than SDSL

asymmetrical services Asymmetrical VDSL is capable of providing datarates to the user of up to 52 Mbps, making it suitable for transporting high-speed applications such as real-time video streaming The trade-off for thishigh speed is restricted reach This requires that the customer be locatedclose to the CO or that the infrastructure access gateway resides outsidethe CO (and closer to the customers) in a remote terminal (RT)

Figure 3 - Access Technologies and Speeds

Satellite

Satellite broadband Internet service like cable, is a shared medium,meaning that privacy may be compromised and performance speeds mayvary depending upon the volume of simultaneous use Anotherdisadvantage of Internet - over-satellite is its susceptibility to disruption inbad weather On the other hand, the big advantage of satellite is its

solution for rural or remote areas not served by other technologies

Powerline Communication (PLC)

Power utilities around the world are recognising the natural competitiveadvantage they have in telecommunications This comes from the use ofinfrastructure they have in place (ducting, building access, poles), theirsystems (billing, call centres), a strong relationship with and anunderstanding of a large customer base, and a core competency in networkmanagement and maintenance It is a natural extension of businessactivity for a power company to enter into telecommunications

New developments in Powerline Communication (PLC) are making itpossible for these utilities to enter the more lucrative broadband market.Over the years a large number of utilities have entered thetelecommunications market Some started to look at core electricityapplications such as Automated Meter Reading (AMR) others started toexploit their internal telecom networks and offered access to theirinfrastructure on a wholesale basis

Others made poles and towers available for new telcos to string their owntelecom infrastructure Increasingly however, we are starting to seeelectricity utilities taking a higher-level strategic interest in the telco

the world are recognising the natural competitive.

Figure 4 - Internet Access Technologies

HomePlug-AV – Keep an Eye on Power

HomePlug-AV is gaining interest as with characteristics capable ofsupporting multiple High Definition TV streams simultaneously using asingle A/C power outlet are essentially impressive

In a recent demo, a pioneer customer electronics manufacturer showedvideo streams being sent simultaneously between A/C power outletscommon in any home or office They were using a prototype version of anemerging standard for high-speed audio/video applications over the 110vpowerline with speeds up to 170 Mbps and with full QoS support