Enhancing Plug and Play Capabilities in Body Area Network Protocols A Major Qualifying Project Report: Submitted to the Faculty Of the WORCESTER POLYTECHNIC INSTITUTE In partial fulfillment of the requirements for the Degree of Bachelor of Science By: ____________________________ Ryan Danas ____________________________ Douglas Lally ____________________________ Nathaniel Miller ____________________________ John Synnott Date: March 10, 2014 Approved: ____________________________ Prof. Krishna Kumar Venkatasubramanian, Advisor ____________________________ Prof. Craig A. Shue, Co-Advisor 1 Abstract This project aimed to create a plug-and-play protocol for Body Area Networks (BANs). This protocol enables communication between a diverse number of devices and a base station, regardless of equipment manufacturer. Previous BANs rely on either proprietary software, or protocols that are specialized to the physical device. This protocol takes a more universal approach, allowing any arbitrary device to participate in a BAN without introducing any significant overhead or running cost to the operation of that BAN. Unlike previous approaches, any existing motes and the base station will not have to be updated. Only new devices being added to the BAN will have to implement the protocol before connecting. Our protocol introduces overhead that reduced the performance and lifetime of the motes used in our BAN. 2 Table of Contents Contents Abstract ......................................................................................................................................................... 2 Table of Contents .......................................................................................................................................... 3 List of Figures ............................................................................................................................................... 5 List of Tables ................................................................................................................................................ 7 1. Introduction ............................................................................................................................................... 8 2. BAN Hardware Investigation.................................................................................................................. 10 2.1 Base Station Platform ....................................................................................................................... 10 2.2 Sensing Platforms ............................................................................................................................. 11 2.2.1 Emotiv ........................................................................................................................................ 11 2.2.2 Shimmer Sensing Platform ........................................................................................................ 12 2.2.3 Operating System Platforms ...................................................................................................... 13 3. BAN System Model ................................................................................................................................ 14 3.1 BAN Workflow ................................................................................................................................. 14 3.2 BAN Design, State Machines & Transition Tables .......................................................................... 16 4. Plug and Play Body Area Network ......................................................................................................... 19 4.1 Plug and Play Restrictions in Previous BANS .................................................................................. 20 4.2 Application Layer Protocol for a Plug and Play BAN ...................................................................... 20 4.2.1 Packet Structures ........................................................................................................................ 21 4.3 Firmware Implementation ................................................................................................................. 31 4.3.1 Mote Firmware Architecture ...................................................................................................... 32 4.4 Base Station Implementation ............................................................................................................ 41 4.4.1 Application Architecture ............................................................................................................ 41 3 4.4.2 Technologies Utilized ................................................................................................................ 45 4.4.3 User Interface Design................................................................................................................. 46 4.4.4 BAN Base Station Application .................................................................................................. 47 5. Plug and Play BAN Performance Analysis ............................................................................................. 54 5.1 Testing Scenarios .............................................................................................................................. 54 5.1.1 Shimmer Results ........................................................................................................................ 54 5.1.2 Mote Lifetime Test..................................................................................................................... 56 5.1.3 Control Message Latency Test ................................................................................................... 58 5.1.4 Base Station Battery Life Test ................................................................................................... 59 5.1.5 BAN Throughput Test ............................................................................................................... 60 5.2 Test Results ....................................................................................................................................... 61 5.2.1 Mote Lifetime Test Results ........................................................................................................ 62 5.2.2 Control Message Latency Test Results ...................................................................................... 62 5.2.3 Base Station Lifetime Test ......................................................................................................... 68 5.2.4 BAN Throughput Test Results ................................................................................................... 68 5.3 Untested Metrics ............................................................................................................................... 69 5.3.1 Packet Loss ................................................................................................................................ 69 5.3.2 Transmission Distance ............................................................................................................... 70 5.3.3 Maximum BAN Size .................................................................................................................. 70 5.3.4 BAN Goodput Over Time (Plug and Play Protocol Overhead) ................................................. 70 5.3.5 CPU Usage ................................................................................................................................. 71 5.3.6 Data Streaming Latency ............................................................................................................. 71 6. BAN Plug and Play Analysis .................................................................................................................. 72 6.1 Plug and Play Evaluation: Shimmer BtStream vs. Our BAN Protocol ............................................. 73 7. Conclusion .............................................................................................................................................. 75 8. Future Work ............................................................................................................................................ 76 8.1 Threat Modeling ................................................................................................................................ 76 4 8.2 Embedded System Cryptography...................................................................................................... 76 8.3 Honeypot ........................................................................................................................................... 77 8.4 Alternative Communication .............................................................................................................. 77 8.5 Alternative Sensing Platforms .......................................................................................................... 78 8.6 Expanding the Plug and Play Protocol .............................................................................................. 79 9. References ............................................................................................................................................... 79 Appendices .................................................................................................................................................. 84