Femtocells E-Book

Jie Zhang

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 530

Veröffentlichungsjahr: 2011

Beschreibung

This book provides an in-depth guide to femtocell technologies In this book, the authors provide a comprehensive and organized explanation of the femtocell concepts, architecture, air interface technologies, and challenging issues arising from the deployment of femtocells, such as interference, mobility management and self-organization. The book details a system level simulation based methodology addressing the key concerns of femtocell deployment such as interference between femto and macrocells, and the performance of both femto and macrocell layers. In addition, key research topics in interference modeling and mitigation, mobility management and Self-Organizing Network (SON) are highlighted. The authors also introduce HNB/HeNB standardization in 3GPP.. Furthermore, access methods (closed, open and hybrid), applications, timing synchronization, health issues, business models and security are discussed. The authors also provide a comparison between femtocells and other indoor coverage techniques such as picocells, repeaters, distributed antenna systems and radio over fiber. Lastly, both CDMA and OFDMA based femtocells are covered. Key Features: * Provides a comprehensive reference on femtocells and related topics * Offers the latest research results on femtocells based on simulation and measurements * Gives an overview of indoor coverage techniques such as picocells, repeaters, distributed antenna systems, radio over fiber and femtocells * Includes chapters on femtocell access network architecture, air interface technologies (GSM, UMTS, HSPA, WiMAX and LTE), femtocell simulation, interference analysis and mitigation in femto/macrocell networks, mobility management in femto/macrocell networks, femtocell self-organization and other key challenges such as timing synchronization and security faced by femtocell deployment * Points to over 240 references from 3GPP, The Femto Forum, journals and conference proceedings This book will be an invaluable guide for RF engineers from operators, R&D engineers from femtocells hardware manufacturers, employees from regulatory bodies, radio network planners, academics and researchers from universities and research organizations. Students undertaking wireless communications courses will also find this book insightful.

Leseprobe

Contents

About the Authors

Preface

Acknowledgements

Acronyms

1 Introduction

1.1 The Indoor Coverage Challenge

1.2 Concepts of Femtocells

1.3 Why is Femtocell Important?

1.4 Deployment of Femtocells

1.5 Important Facts to Attract More Customers

1.6 The Structure of the Book

References

Indoor Coverage Techniques

2.1 Improvement of Indoor Coverage

2.2 Outdoor Cells

2.3 Repeaters

2.4 Distributed Antenna Systems (DAS)

2.5 Radiating or Leaky Cable

2.6 Indoor Base Stations

2.7 Comparison of Indoor Coverage Techniques

References

3 Access Network Architecture

3.1 Overview

3.2 GAN-Based Femtocell-to-Core Network Connectivity

3.3 3GPP Iuh (Iu-Home) for Home NodeB

3.4 Evolution to IMS/HSPA+/LTE

3.5 Architecture with IMS Support

References

4 Air-Interface Technologies

4.1 Introduction

4.2 2G Femtocells: GSM

4.3 3G Femtocells: UMTS and HSPA

4.4 OFDM-Based Femtocells

References

5 System-Level Simulation for Femtocell Scenarios

5.1 Network Simulation

5.2 Link and System Level Simulations

5.3 Wireless Radio Channel Modelling

5.4 Static and Dynamic System-Level Simulations

5.5 Static System-Level Methodology for WiMAX Femtocells

5.6 Coverage and Capacity Analysis for WiMAX Femtocells

5.7 Overview of Dynamic System-Level Simulation

References

6 Interference in the Presence of Femtocells

6.1 Introduction

6.2 Key Concepts

6.3 Interference Cancellation

6.4 Interference Avoidance

6.5 Interference Management with UMTS

6.6 Conclusion

References

7 Mobility Management

7.1 Introduction

7.2 Mobility Management for Femtocells in 3GPP

7.3 Femtocell Characterization

7.4 Access Control

7.5 Paging Procedure

7.6 Cell Selection and Reselection

7.7 Cell Handover

References

8 Self-Organization

8.1 Self-Organization

8.2 Self-Configuration, Self-Optimization and Self-Healing

8.3 Self-Organization in Femtocell Scenarios

8.4 Start-Up Procedure in Femtocells

8.5 Sensing the Radio Channel

8.6 Self-Configuration and Self-Optimization of Femtocell Parameters

References

9 Further Femtocell Issues

9.1 Timing

9.2 Femtocell Security

9.3 Femtocell Location

9.4 Access Methods

9.5 Need for New Applications

9.6 Health Issues

References

Index

This edition first published 2010

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Library of Congress Cataloguing-in-Publication Data

Zhang, Jie, 1967-

Femtocells: technologies and deployment/Jie Zhang, Guillaume de la Roche.

p. cm.

Includes bibliographical references and index. ISBN 978-0-470-74298-3 (cloth)

1. Femtocells. 2. Wireless LANs – Equipment and supplies. 3. Cellular telephone

systems – Equipment and supplies. 4. Radio relay systems. 5. Telephone repeaters.

I. De la Roche, Guillaume. II. Title.

TK5103.2.Z524 2010

621.382′1-dc22

2009039766

for

MALCOM FOSTER

for his tireless reviews

About the Authors

Jie Zhang is a professor of wireless communications and networks and the director of CWiND (Centre for Wireless Network Design, www.cwind.org) at the DCST (Department of Computer Science and Technology) of UoB (University of Bedfordshire). He joined UoB as a Senior Lecturer in 2002, becoming professor in 2006.

He received his PhD in industrial automation from East China University of Science and Technology (www.ecust.edu.cn), Shanghai, China, in 1995. From 1997 to 2001, he was a postdoctoral research fellow with University College London, Imperial College London, and Oxford University.

Since 2003, he has been awarded more than 12 projects worth over 4 million Euros (his share). In addition, Professor Zhang is responsible for projects worth a few million Euros with his industrial partners. These projects are centred on new radio propagation models, UMTS/HSPA/ WiMAX/LTE simulation, planning and optimization, indoor radio network design and femtocells.

He is an evaluator for both EPSRC (Engineering and Physical Science Research Council) and the EU Framework Program.

He has published over 100 refereed journal and conference papers. He is the chair of a femtocell panel titled Femtocells: Deployment and Applications at IEEE ICC 2009. He has been a panellist at IEEE Globecom and IEEE PIMRC.

Prof. Zhang is an Associate Editor of Telecommunication Systems (Springer) and is in the editorial board of Computer Communications (Elsevier).

Guillaume de la Roche has been working as a research fellow at the Centre for Wireless Network Design (UK) since 2007. He received the Dipl-Ing in Telecommunication from the School of Chemistry Physics and Electronics (CPE Lyon), France, an MSc degree in Signal Processing (2003) and PhD in Wireless Communication (2007) from the National Institute of Applied Sciences (INSA Lyon), France.

From 2001 to 2002 he was a research engineer with Siemens-Infineon in Munich, Germany. From 2003 to 2004 he worked in a small French company where he deployed and optimized 802.11 wireless networks. He was responsible for a team developing a WiFi planning tool. From 2004 to 2007 he was with the CITI Laboratory at INSA Lyon, France. His research was about radio propagation in indoor environments and WiFi network planning and optimization.

He has supervised a number of students and taught laboratory courses in GSM network planning. He still teaches object programming and Java at Lyon 1 University. He has been involved in EU and UK funded projects, and is currently the principal investigator for an FP7 project (CWNetPlan) related to the coexistence and the optimization of indoor and outdoor wireless networks. His current research includes femtocells, channel modelling, and wireless network planning and optimization.

Alvaro Valcarce obtained his MEng in telecommunications engineering from the University of Vigo (Spain) in 2006. During 2005 he worked at ‘Telefonica I+D’ in Madrid (Spain), integrating an applications-streaming platform into an ‘ATG Dynamo Server’, as well as developing a system for ‘applications-on-demand’.

In 2006, he worked as a researcher at the WiSAAR consortium in Saarbruecken (Germany), where he performed several WiMAX field trials, radio propagation measurements, data analysis and study of radio performance. The outcome of this project was an empirical propagation model especially designed for WiMAX coverage prediction at 3.5 GHz in urban environments.

Alvaro joined the Centre for Wireless Network Design (CWiND) of the University of Bedfordshire (UK) in 2007 with the support of a European Marie Curie Host Fellowship for Early Stage Research Training (EST). During 2008, he was one of the main researchers of the first British EPSRC-funded research project on femtocells – ‘The feasibility study of WiMAX-based femtocells for indoor coverage’ (EP/F067364/1). His PhD is integrated in the FP6 RANPLAN-HEC project (MEST-CT-2005-020958): ‘Automatic 3G/4G Radio Access Network Planning and Optimization – A High End Computing Approach’. This project studies, among other wireless topics, the indoor-to-outdoor wireless channel and its applicability to network planning. Alvaro’s main research interests currently include radio channel modelling, multicarrier systems, finite-difference algorithms, wireless networks planning and optimization methods and femtocells.

David López-Pérez received his bachelor and master degrees in telecommunication from Miguel Hernandez University, Elche, Alicante (Spain) in 2003 and 2006, respectively. He joined Vodafone Spain in 2005, working at the Radio Frequency Department in the area of network planning and optimization. He participated in the development of the Vodafone Automatic Frequency Planning tool for GSM and DCS networks.

He took up a research PhD scholarship at the Cork Institute of Technology in Ireland in 2006 for a year where he worked on a project called ‘UbiOne The Multi-Modal WiFi Positioning System’. This project proposed a multi-modal positioning system utilizing offthe-shelf WiFi based equipment for a cost-effective solution, providing accurate location data in office/open building and campus environments.

Nowadays, he is a Marie-Curie fellow at the Centre for Wireless Network Design at the University of Bedfordshire, and his research is supported by the ‘FP6 Marie Curie RANPLAN-HEC project’ (MESTCT-2005-020958). He also participates as a guest researcher in the first EPSRC-funded research project on femtocells – ‘The feasibility study of WiMAX based femtocells for indoor coverage’ (EP/F067364/1) in the UK. His research is focused on the study of 2G/3G/LTE/WiMAX network planning and optimization, and self-organization for macrocells and femtocells two-tier networks. He is also interested on cooperative communications, optimization and simulation techniques.

Enjie Liu is a Senior Lecturer at the Department of Computer Science and Technology of the University of Bedfordshire. She joined UoB in 2003. She is a member of the networking teaching group in the department and responsible for delivering both wired and wireless modules to undergraduates as well as post graduates. She received her PhD from Queen Mary College, University of London in 2002. Then she worked as research fellow with the Centre for Communication Systems Research (CCSR), the University of Surrey. She was granted a Newly Appointed Lecturers Award by The Nuffield Foundation. She was a co-investigator of EU FP6 RANPLAN-HEC project that oversees 3G/4G radio network planning and optimization. She was the principal investigator of the first EPSRC funded research project on femtocells – ‘The feasibility study of WiMAX based femtocell for indoor coverage’ (EP/F067364/1). Before her PhD, she had more than 10 years of industrial experience in telecommunications with Nortel Networks. She first worked with Nortel in China on installation, on-site testing and maintenance of wireless networks such as GSM and CDMA. She also worked with the Nortel Networks Harlow Laboratory in the UK.

Hui Song is a PhD student and research associate at the Center for Wireless Network Design (CWiND), University of Bedfordshire. His interest is network planning and optimization technologies. His current focus is on modeling OFDM fading channels. Before joining CWiND, he was the manager of the technology department at Bynear Telecom Software Ltd, Shanghai, China. There he was responsible for developing and maintaining the nation-first network planning and optimization suite (including GSM, WCDMA and TD-SCDMA). Song holds a mathematics degree from Fudan University, Shanghai, China. He currently resides in the United Kindom.

Preface

In cellular networks, it is estimated that ⅔ of calls and over 90% of data services occur indoors. However, some surveys show that many households and businesses experience a poor indoor coverage problem. It has been identified that poor coverage is the main reason for churn, which is very costly for operators in saturated markets. How to provide good indoor coverage cost effectively is thus a demanding challenge for operators.

The recent development of femtocells provides a fresh opportunity for operators to address the poor indoor coverage problem. Femtocells represent a more cost-effective solution than do other indoor solutions such as DAS (Distributed Antenna Systems) and picocells in indoor scenarios such as home and SOHO (Small Office and Home Office). Many operators such as Vodafone and AT&T have expressed a strong interest in femtocells and announced commercial launches of femtocells within their mobile networks, starting in the second half of 2009.

The deployment of a large number of femtocells (in particular, spectrum-efficient cochannel deployment) will have an impact on the macrocell layer. This impact and the performance of both macrocell and femtocell layers have to be fully evaluated before large-scale deployment. The evaluation can be done either through trials or simulationbased approaches. There is currently a lack of documentation that provides a comprehensive and organized explanation for the challenging issues arising from the deployment of femtocells in an existing macrocell network. We therefore believe that there is an urgent need for a book that covers femtocell technologies (such as femtocell architecture and air interface technologies) and the issues arising from femtocell deployment (such as interference modelling and mitigation, self-optimization, mobility management, etc.).

In recent years, CWiND has been funded by the EPSRC (Engineering and Physical Science Research Council) and the European Commission to research femtocells and indoor radio network design. These projects equipped us with a good understanding of femtocell technologies and the challenging issues arising from deployment of femtocells. It is also fortunate that CWiND could dedicate a large amount of human resources from February to June 2009 to the writing of this very much needed book.

In this book, the method used to study femtocell deployment is computer-aided simulation rather than trial based. This method is more convenient and more cost effective.

The book is written in a tutorial style. We believe that it suits a wide range of readers, e.g., RF engineers from operators, R&D engineers from telecom vendors, academics and researchers from universities, consultants for wireless networks and employees from regulatory bodies.

This book is organized as follows:

In Chapter 1 (Introduction), an introduction to femtocell concepts and the book is given. The advantages and disadvantages of using femtocells, the standardization and business models are also briefly touched on.

In Chapter 2 (Indoor Coverage Techniques), an overview of the different indoor coverage techniques is given. As femtocell is mainly used for indoors, we think a brief introduction to other indoor coverage techniques might be useful for readers. In this chapter, the evolution from macrocell to femtocell is presented and the different methods are compared. Advantages and drawbacks of the different techniques, like Distributed Antenna System (DAS), repeaters, and picocells are also given and the main challenges related to femtocells are introduced. It needs to be pointed out that femtocells can also be used outdoors, provided that backhaul connections are available or can be easily established.

In Chapter 3 (Access Network Architecture), the evolution of femtocell architecture from 3GPP Release 8 and different options to ensure the connectivity of the femtocell to the core network are described. Functional split between HNB and HNB-GW, new interfaces such as Iuh are also described. Security aspects are also touched on.

In Chapter 4 (Air Interface Technologies), different air interface technologies for femtocells are presented. In particular, femtocell specific features in the discussed air interfaces are described. The technologies covered in this chapter include Global System for Mobile communication (GSM), Universal Mobile Telecommunication System (UMTS), High Speed Packet Access (HSPA), Wireless Interoperability for Microwave Access (WiMAX) and Long Term Evolution (LTE).

In Chapter 5 (System-Level Simulation for Femtocell Scenarios), the methodology of how to simulate femtocells is detailed. The development of a femtocell simulation tool is presented, from the radio coverage level, to the system level. Simulation methods, including both static and dynamic approaches, are illustrated with some femtocell deployment examples. Coverage and capacity analysis is given for the given scenarios of a hybrid femtocell/macrocell WiMAX network.

In Chapter 6 (Interference in the Presence of Femtocells), interference between femtocell and macrocell (so-called cross-layer interference), as well as between neighbouring femtocells (so-called co-layer interference) are analysed for both CDMA and OFDMA based femto/macro networks. The performance of a UMTS macrocell network in the presence of femtocells is also given. Moreover, some interference cancellation and avoidance techniques are also presented in this chapter.

In Chapter 7 (Mobility Management), issues related to mobility management such as cell selection/reselection and handovers in two-tier femto/macro networks for various access methods (CSG, open access and hybrid access) are discussed in detail. Mobility management is a major issue and presents a big challenge for hybrid femto/macro network.

In Chapter 8 (Self-Organization), issues related to femtocell self-organization are presented. Self-organization includes self-configuration, self-optimisation and self-healing. With self-conguration, the initial femtocell parameters are automatically selected (such as PCI, neighbouring list, channel and power). Self-optimization kicks in when FAPs are operational and optimize the FAP parameters taking into account the fluctuations of the channel and resources available. In order to achieve self-organisation, FAPs should know their radio environments; hence, radio channel sensing techniques such as those using message exchange and measurement report are also described in this chapter. Femtocells are plug-and-play devices, self-organization capability is key to the successful deployment of femtocells.

In Chapter 9 (Further Femtocell Issues), some other important challenges that have to be solved are presented, these include ensuring the timing accuracy, the security and the identification of location of the femtocell devices. In addition, access methods, femtocell applications and health issues are also discussed in this chapter.

No book is perfect and this one is no exception. In order to provide a remedy to this fact, we will present further materials related to this book at the following website: www.deployfemtocell.com. We also plan to create a discussion board at this site, so that the interactions between the authors and readers and between readers themselves can be facilitated. Finally, we hope that you will like this book and give us feedback so that we can improve the book for the next edition.

Acknowledgements

We would like to thank our publishers, Tiina Ruonamaa, Anna Smart, Sarah Tilley, Brett Wells and the rest of the wireless team at Wiley. They produce the largest collection of best wireless books! We are grateful for their encouragement, enthusiasm and vision about this book, as well as for their professionalism. We believe they are all great assets for Wiley! We learned a lot from them. We thank Brett Wells and Dhanya Ramesh for their excellent work at the production stage.

We thank anonymous reviewers for their helpful comments that have improved the quality of this book.

Jie Zhang would like to thank Simon Saunders for the invitation to the Femto Forum meeting in Dallas in December 2008. This gave Jie an overview of the Femto Forum activities. The Femto Forum white paper on WCDMA interference management was also useful for this book.

The authors would like to thank Holger Claussen and Malek Shahid from AlcatelLucent. They both have a great understanding of femtocells. The discussions with them were very helpful.

The authors would like to thank De Chen and Eric (Linfeng) Xia from Huawei Technologies. The discussions with them improved our understanding of LTE femtocells.

We would like to thank John Malcolm Foster, a great friend of ours, for his wisdom and endless corrections of research proposals, research papers and book chapters in the last 7 years. Malcolm corrected the English for all the chapters of this book. We all learned a lot from him in the last few years.

We would also like to thank other CWiND members whose research might be directly/indirectly useful for this book, such as Alpár Jüttner, Raymond Kwan, Á kos Ladányi and Zhihua Lai (according to alphabetic order of surnames). We are really proud of working with so many talented, self-motivated and extremely able young researchers. Together, we have made CWiND a special place with so many achievements in a very short time.

We express our thanks to the EPSRC (Engineering and Physical Science Research Council) and the European Commission for their support of our research on femtocells and indoor radio network design. We would like to extend our thanks to the project partners on these projects Ranplan Wireless Network Design Ltd (in particular, Joyce Wu) and INSA-Lyon (in particular, Jean-Marie Gorce).

We thank all our teachers/supervisors who illuminated us during our studies from the primary school to the PhD. In many ways, they lit up our dreams.

We express our gratitude to all our families for their support throughout the years. We know that without their support, we can not even live in this world.

Jie Zhang would like to thank Joyce for all the work she does at home and, in particular, for her delivery of Jie’s biggest achievements Jennifer and James. Jie is grateful for Jennifer’s love of engineering and believes that she will do better than him in engineering.

Acronyms

3GPP 3rd Generation Partnership Project AAA Authentication, Authorization and Accounting ACIR Adjacent Channel Interference Rejection ACL Allowed CSG List ACLR Adjacent Channel Leakage Ratio ACPR Adjacent Channel Power Ratio ACS Adjacent Channel Selectivity ADSL Asymmetric Digital Subscriber Line AGCH Access Grant Channel AH Authentication Header AKA Authentication and Key Agreement AMC Adaptive Modulation and Coding API Application Programming Interface ARPU Average Revenue Per Unit AS Access Stratum ASE Area Spectral Efficiency ASN Access Service Network ATM Asynchronous Transfer Mode AUC Authentication Centre AWGN Additive White Gaussian Noise BCCH Broadcast Control Channel BCH Broadcast Channel BE Best Effort BER Bit Error Rate BLER BLock Error Rate BPSK Binary Phase-Shift Keying BS Base Station BSC Base Station Controller BSIC Base Station Identity Code BSS Base Station Subsystem BTS Base Transceiver Station CAC Call Admission Control CAPEX CAPital EXpenditure CAZAC Constant Amplitude Zero Auto-Correlation CCCH Common Control Channel CCPCH Common Control Physical Channel CCTrCH Coded Composite Transport Channel CDMA Code Division Multiple Access CGI Cell Global Identity CN Core Network CPCH Common Packet Channel CPE Customer Premises Equipment CPICH Common Pilot Channel CQI Channel Quality Indicator CRC Cyclic Redundance Check CSG Closed Subscriber Group CSG ID CSG Identity CSI Channel State Information CTCH Common Traffic Channel CWiND Centre for Wireless Network Design DAS Distributed Antenna System DCCH Dedicated Control Channel DCH Dedicated Channel DCS Digital Communication System DFT Discrete Fourier Transform DL DownLink DoS Denial of Service DPCCH Dedicated Physical Control Channel DPDCH Dedicated Physical Data Channel DRX Discontinuous Reception DSCH Downlink Shared Channel DSL Digital Subscriber Line DTCH Dedicated Traffic Channel DXF Drawing Interchange Format EAGCH Enhanced uplink Absolute Grant Channel EAP Extensible Authentication Protocol ECRM Effective Code Rate Map EDCH Enhanced Dedicated Channel EESM Exponential Effective SINR Mapping