This page intentionally left blank PREFACE This document is being provided to the mining industry as a working draft. The intent is to make information available to labor, industry, regulators, and academia that is relevant to the Communications and Tracking systems that are being installed for compliance with the MINER Act. As a working draft, the document has not yet been through the rigorous external peer review process that NIOSH publications require before being distributed as an official NIOSH document. The document has been reviewed internally; however, it was determined that NIOSH review and release process would not likely be completed for the June 15, 2009 compliance date that is required by the MINER Act. Therefore, the decision was made to distribute this document as a working draft and to follow with a final publication as quickly as possible. We would like to acknowledge the contributions of the Defense Information Systems Agency, Joint Spectrum Center, Annapolis, MD which prepared much of the material contained in this document under an Inter-Agency Agreement (IAA) with NIOSH. We also want to acknowledge the contributions of the NIOSH research staff, whose extraordinary effort made this document possible in an exceptionally short period of time. Tutorial on Wireless Communications & Electronic Tracking TABLE OF CONTENTS 1. INTRODUCTION ...................................................................................................4 2. CT TECHNOLOGY OVERVIEW............................................................................6 2. 1 COMMUNICATIONS BASICS ....................................................................................6 2.1.1 Physical Communications Links .......................................................................7 2.1.2 Networks ...........................................................................................................8 2.1.3 Wireless versus Wired Systems ......................................................................10 2.2 COMMUNICATIONS SYSTEMS PRINCIPLES OF OPERATION ........................11 2.2.1 Hardwired Systems ..................................................................... 11 2.2.2 Wireless Systems ........................................................................ 12 2.3 TRACKING SYSTEMS PRINCIPLES OF OPERATIONS ......................................24 2.3.1 Manual Tracking Systems ............................................................... 24 2.3.2 Reader-based Tracking Systems ........................................................ 24 2.3.3 Radio Node-Based Tracking Systems ................................................. 28 2.4 NETWORK OPTIONS .................................................................................................29 2.5 MINE OPERATIONS CENTER ..................................................................................31 2.5.1 Tracking Displays ......................................................................... 31 2.5.2 Surface Communications ................................................................. 32 3. COMMUNICATIONS SYSTEM PERFORMANCE ..............................................34 3.1 GENERAL PERFORMANCE CONSIDERATIONS ..................................................34 3.1.1 Physical Communications Link ......................................................... 34 3.1.2 Network Performance ..................................................................... 42 3.1.3 Management of the Electromagnetic Spectrum ...................................... 43 3.1.4 Modeling and Analysis ................................................................... 44 3.1.5 Maintenance and Testing ................................................................. 46 3.1.6 Performance Goals and Metrics ........................................................ 46 3.1.7 Wireless Systems Considerations ...................................................... 50 3.2 Point-to-Point Communications ................................................................. 51 3.3 Wired Communications ................................................................................................51 3.3.1 Twisted Pair ................................................................................. 51 3.3.2 Ethernet Cable .............................................................................. 51 3.3.3 Fiber Optic Cable .......................................................................... 52 3.4 LEAKY FEEDER SYSTEMS.......................................................................................52 3.4.1 Description .................................................................................. 52 3.4.2 Components ................................................................................. 53 3.4.3 Transmission Media ....................................................................... 55 3.4.4 Network Operations ....................................................................... 57 3.4.5 System Implementation ................................................................... 58 3.4.6 Maintenance and Inspection ............................................................. 60 3.4.7 Performance & Limitations .............................................................. 61 3.5 MEDIUM FREQUENCY SYSTEMS...........................................................................62 3.5.1 Description .................................................................................. 62 3.5.2 Components ................................................................................. 64 i Tutorial on Wireless Communications & Electronic Tracking 3.5.3 Transmission Media ....................................................................... 65 3.5.4 Network Operations ....................................................................... 66 3.5.5 System Implementation ................................................................... 66 3.5.6 Maintenance and Inspection ............................................................. 71 3.5.7 Performance & Limitations .............................................................. 72 3.6 NODE-BASED SYSTEMS ..........................................................................................74 3.6.1 Description .................................................................................. 74 3.6.2 Components ................................................................................. 79 3.6.3 Transmission Media ....................................................................... 80 3.6.4 Network Operations............................................................................................82 3.6.5 System Implementation .....................................................................................84 3.6.6 Maintainability and Inspection .......................................................... 85 3.6.7 Performance and Limitations ............................................................ 86 3.7 THROUGH-THE-EARTH SYSTEMS ........................................................................89 3.7.1 Description .........................................................................................................89 3.7.2 Components .......................................................................................................91 3.7.3 Transmission Media ...........................................................................................91 3.7.4 Network Operations ...........................................................................................92 3.7.5 System Implementation .....................................................................................92 3.7.6 Maintenance and Inspection ..............................................................................93 3.7.7 Performance and Limitations .............................................................................94 3.8. Communications Technology Comparisons ............................................................. 95 3.8.1 Comparison Matrix ............................................................................................96 4. ELECTRONIC TRACKING SYSTEM PERFORMANCE ....................................96 4.1 Tracking Techniques .....................................................................................................97 4.2 Reader-Based ................................................................................................................98 4.2.1 Zone-Based RFID ..............................................................................................98 4.2.2 Reverse RFID ...................................................................................................107 4.3 Node-Based Communications with Integrated Tracking ............................................116 4.3.1 Description .......................................................................................................116 4.3.2 Components .....................................................................................................117 4.3.3 Transmission Media .........................................................................................117 4.3.4 Network Operations .........................................................................................117 4.3.5 System Implementation ...................................................................................118 4.3.6 Maintainability and Inspection ........................................................................118 4.3.7