WINLAB Capturing an Experiment: A Wireless Testbed Perspective Ivan Seskar Seskar (at) winlab (dot) rutgers (dot) edu Rutgers, The State University of New Jersey

WINLAB Experiment Support Architecture System Control Measure Deploy & Configure Experimenter Results Definition

WINLAB Orbit Services

WINLAB Orbit Measurement Library (OML)

WINLAB Defining an Experiment

WINLAB Experiment Definition Experiment.name = "tutorial-1" Experiment.project = "Orbit::Tutorial" Experiment.startMode = Experiment::REBOOT # # Define nodes used in experiment # node([2, 3], :sender) {|n| n.prototype(" { :if => Node::W0_IF, :packetSize =>128 Experiment.parameter("packetSize"), :rate => Experiment.parameter("rate") }) } node([3, 4]) {|n| n.prototype(" {:if => Node::W0_IF}) } # # Configure environment # node("/*/*").net.w0 {|n| n.essid = "HelloWorld" n.mode = "ad-hoc" n.channel = 1 n.xmitPower = 1 n.bitrate = "11Mbps" # Force single rate n.ip = "%10.0.%x.%y" } # Start experiment whenReady {|e, n| p.packetSize = 1024 p.rate = 250 e.sleep 5.0 e.done } OMF Experiment Description Language, OEDL

WINLAB ORBIT Grid

WINLAB 8 Hardware  Differences in commercial hardware  Difference in tolerances and ageing for various low cost components Issues Affecting Archiving/Repeatability Software  Software or firmware bugs that may manifest as inconsistent experimental results Environment  Uncontrolled interference over time and space  Co-located infrastructure, opening and closing of doors, movement of people etc.

WINLAB 9 Device Calibration Setup

WINLAB 10 Transmitter calibrationReciver calibration Calibrate transmit and receive side of the wireless cards Record corrections to be applied for each card based on the discrepancies observed Calibration: Device Characterization

WINLAB 11 Calibration: Temporal repeatability The Experiment

WINLAB 12 Calibration: Spatial repeatability Blue sender sends to blue receiver Yellow sender sends to yellow receiver Experiment repeated on a different set of nodes with same topology Spatial throughput variations w.r.t mean for experiment duration averaged over different experimental runs

WINLAB 13 Calibration Node calibration procedure necessary to address hardware dependencies Temporal variation less than device variability Periodic re-calibration necessary Need to automate the on-site calibration procedure so that it can “monitor” the testbed “drift” Bounds on acceptable performance – Baseline standard

WINLAB Archiving ORBIT Experiments Existing Support: Image Experiment script and/or commands on the console State of services and environmental traces Measurements (if using OML) Device calibration info What is missing Full metadata State of devices Full RF environment (not necessarily critical for repeatability)

WINLAB Wild Environment: WiMAX Basestation Roof Antenna Wide-area packet based communication system (4G) Operational with an educational license Basestation (IDU) Unit RF (ODU) Amplifier

WINLAB Measured RSSI Wild Environment: Coverage

WINLAB Wild Environment: Mobility Trajectory RSSI

WINLAB Instead of Conclusion Repeatability/replayability incentive Standardized anomaly monitoring Storing metadata in archives Baseline performance tests and calibration