NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 prowler PROBABILISTIC WIRELESS NETWORK SIMULATOR  Features:  Event-driven  Deterministic or Probabilistic  Command line / GUI  Visualization  Statistics / Optimization  Any number of motes / any application  Fast application prototyping  MATLAB-based

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 prowler can simulate: distance ‘ideal’ measured Signal strength Send_PacketPacket_Sent Channel_Idle_Check Waiting_TimeBackoff_TimeTransmission_Time  Radio Propagation  Transmit, Receive, Collision  Model for signal strength:  based on distance  deterministic or probabilistic (fading)  location ( LARGE VARIATION)  time ( SMALL VARIATION)  asymmetric links  random failures/external disturbances  TinyOS w/ MAC-layer  Complete MAC-layer protocol  Simplified set of  Events  Commands + Application (plug-in)

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS Topology Information for the Motes  coordinates of the motes  can change during simulation (may be random) 2. Visualization definition (optional)  events  visual effects 3. Application Code  actions to events  generate new events case 'Packet_Received' if rand<0.7 Send_Packet(RadioStream(data, memory.signal_strength)); end Application % Event_name Target Color Size anim_def={... {'Init_Application',1,[0 0 0 ],small},... {'Packet_Sent', 2,[1 0 0 ],small},... {'Packet_Received', 3,[1 0 0 ],small},... Topology = [1,1;1,2;2,1; 2,2]; mote_IDs = [1,2,3,4];

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 Example Application: Flood Commands Simulator switch event case 'Init_Application' signal_strength=100; %%%%%%%%%% Memory initialized here %%%%%%%%%%%% memory=struct('send',1, 'signal_strength', signal_strength); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% if ID==1 % first node starts flood Set_Clock(1000) end case 'Packet_Sent' % do nothing case 'Packet_Received' if memory.send p=sim_params('get_app', 'P'); if rand<p Send_Packet(radiostream(data, memory.signal_strength)); end memory.send=0; end case 'Collided_Packet_Received' % this is for debug purposes only case 'Clock_Tick' Send_Packet(RadioStream(data, memory.signal_strength)); end MATLAB Events

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 prowler – Main GUI Application and radio definition Graphic Visualization Event Monitor transmit wait receive Text messages Memory Dump of mote ID# 2: send: 0 signal_strength: 1

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 Ideal transmission function prowler – Simulation Parameters MAC-layer parameters Fading effect parameters Reception condition

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 Goal: Optimize performance Start Optimization with prowler Example: Flood in 2D with randomized retransmission (10x10 grid) Parameters: s – signal strength p – retransmission probability

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 Optimization with prowler Simple performance metrics:

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 Optimization with prowler Composed performance metrics (  ‘ adjustable interfaces ’) Metrics are composed from the number of receiving nodes & consumed energy: Emphasis on accuracy Emphasis on power consumption optimum

NEST PI Meeting July 9-12, 2002Copyright © Vanderbilt University/ISIS 2002 prowler - Conclusions  Fast and easy prototyping in MATLAB  Captures the event-driven nature of TinyOS  Algorithm testing in  deterministic environment  probabilistic environment  dynamically changing environment  Easy debugging  Application area:  communication protocols, routing  arbitrary application prototyping  optimization, parameter tuning  Provides visualization  Easy to expand; plugins