UMTSThird generation mobile communications boosting wireless efficiency Publisher: Willtek Communications GmbH Gutenbergstr. 2-4 85737 Ismaning Germany e-mail:
[email protected] http://www.willtek.com Co-Author: Helmut Visel, Acterna Eningen GmbH © Copyright 2002 Willtek Communications GmbH. All rights reserved. Willtek Communications, Willtek and its logo are trademarks of Willtek Communications GmbH. All other trademarks and registered trademarks are the property of their respective owners. Content UMTS – a communications revolution 6 Three generations of mobile communications 8 Services – ensuring the success of UMTS 10 New technology, new roles 12 The fundamentals of UMTS 15 3G frequencies 15 Frequency bands for UMTS 18 Minimum bandwidth requirements 20 Inside the UMTS architecture 22 Network overview 24 From handset to network – the user equipment 25 Virtual home environment 30 Service capabilities and APIs 32 UMTS system architecture 34 UTRAN components 35 Node B 38 Serving radio network subsystems and drift radio network subsystems 40 Handovers 41 Hard handovers 42 Softer and soft handovers 43 Role of the Iur interface during handover 45 UMTS logical planes 46 Transport network control plane 46 Control plane 46 Control plane components 47 User plane 50 User plane components 50 ATM in the core network 53 The future – all-IP networks? 55 Key terms 57 UMTS air interface 62 Multiple access routes 63 Frequency division duplex (FDD) 65 Time division duplex (TDD) 66 FDMA-based networks 67 CDMA – it’s party time 68 CDMA-based networks 70 CDMA cells 72 Orthogonal codes and multiplexing 73 Features of the UMTS radio interface 74 Frequency, code, and phase 75 CDMA air interface challenges 76 The “near-far” problem 76 Cell breathing 78 Variable rate transmission 79 Glossary 80 Bibliography 86 Information sources 87 UMTS – a Almost everyone today seems to own at least one mobile device.