Introduction

Repository provides simulation software developed for "Synchronization-free TDoA localization method for large scale wireless networks" paper submitted to Indoor Positioning and Indoor Navigation 2017 Conference. Software consists OMNET++ simulation models and Matlab scripts for data analysis. Software is capable of simulating mobile node localization in various configurations discussed in article (different hardware clocks, various infrastructure node deployments, stationary and moving mobile nodes etc.).

Simulation uses modified imperfect hardware clock model for OMNET++ created by Jens Steinhauser.

Prerequisites

• OMNET++ 5.0 with INET 3.4.0 on any supported platform
• Familiarity with OMNET++ (running and developing simulation).

Repository structure

Brief description of directories and files in repository

• src directory

  • Definitions of main simulation components such as: mobile and anchor nodes, ranging applications, hardware clocks etc. written in C++ and NED languages.

• simulations directory

  • MovingNetwork.ned and StationaryNetwork.ned files define artificial simulation areas for moving and stationary mobile node respectively.
  • ipin.ini defines all simulation cases (number of nodes, speed, hardware clock precision etc.).
  • Bash scripts (prefixed with run) running various sets of simulations in parallel.

• matlab

  • Matlab scripts for data analysis.

Components

OMNET++ is a component-based simulation environment, therefore simulations are composed of complex component structures. Such components represent various entities (e.g. wireless nodes) and implement simulation logic.

Components hierarchy:

• IHardwareClock

  Common interface for all hardware clocks

  • HardwareClock

    Common base hardware clock representation.

    • NoneDrift

      Perfect hardware clock without any drift.

    • ConstantDrift

    • BoundedDrift

    • BoundedDriftVariation

      Various hardware clocks with different drifts as described in Jens Steinhauser's paper.

• IRangingApplication

  Common interface for ranging applications running on wireless nodes.

  • RangingApplication

    Common base component for all ranging applications regardless of particular localization method.

    • TDoAAnchorRangingApplication
    • TDoAMobileRangingApplication

    Ranging application implementing logic required by proposed localization method.

• RangingHost

  RadioHost extends INET's MobileHost component and represents a freestanding wireless node. It includes and interconnects three basic sub components: hardware clock, ranging application and network interface. By design RadioHost is highly configurable, e.g. it is possible to define a ranging hist running TDoAAnchorRangingApplication application and freely exchange hardware clocks.

There are also number of *.msg files defining radio frames.

First steps

1. Checkout this repository and import it in OMNET++,

2. Build & Run simulation in GUI mode.

3. Simulator windows should show up in a moment. In a simulator's pop-up dialog choose TDoA_moving_perfect_clock configuration and run no. 0.

4. Proceed with simulation and close simulator when it is done.

5. A CSV file with simulation results will appear in simulations directory. The file name will correspond to simulation case configuration (it will include information about initial node position, speed, used clock etc.). In this case file should be named tdoa_perf_1mps_0deg_100m_100m - mobile node was equipped with perfect clock and was moving from initial position (100m, 100m) at constant speed (1m/s). For more details regarding file name convention refer to documentation in analyzeMovingNode.m.

6. Analyze simulation results in Matlab using following scripts: analyzeMovingNode.m for moving mobile nodes and analyzeStationaryNode.m for stationary mobile nodes. In this case run analyzeMovingNode.m with following arguments:

   >> [approxPos, realPos, absPosErrs, absErrStats]=analyzeMovingNode('../simulations', 'tdoa', 100, 100, 1, 0);

Author

Tomasz Jankowski <t.jankowski AT pwr.edu.pl>