Rapid Development and Flexible Deployment of Adaptive Wireless Sensor Network Applications

Chien-Liang Fok, Gruia-Catalin Roman, Chenyang Luhttp://mobilab.wustl.edu/projects/agilla

Mobile Computing LaboratoryDistributed Object Computing LaboratoryDepartment of Computer Science and Engineering

2MURI 2005

Motivation

Software development for sensor networks is hard Limited resources Difficult to debug Large & highly dynamic network

Existing software lacks flexibility Entire network runs just one application Cannot adapt to changes in

• the environment• user requirements

3MURI 2005

Motivating Example Three applications: 1) Environmental Monitoring,

2) Fire Detection, 3) Fire Tracking

4MURI 2005

Agilla: A Flexible Middleware for Sensor Networks

Env. monitoring agentFire detection agentFire tracking agent

Sensor network as a shared computing resource Flexible application deployment

5MURI 2005

Agilla’s System Architecture

TinyOS

Node @ (1,1)

Tuplespace

Agilla Middleware

Agents

TinyOS

Node @ (2,1)

Tuplespace

Agilla Middleware

Agentsmigrate

remote accessNeighbor

ListNeighbor

List

Middleware Services Middleware Services

6MURI 2005

Agilla’s Computational Model

Cloneor

MigrateCode

Stack

Heap

ConditionCodes

PC

Two variants of each: 1) Strong (code + state) 2) Weak (code only)

7MURI 2005

Location-Base Addressing

Nodes are addressed by location

(3,1) (3,2)(3,3)

(2,2)

(1,1) (1,3)

clone to (3,3)clone to (3,1)

Fire DetectionAgent

8MURI 2005

Tuple Space-Based Coordination Content-addressable shared memory

Tuple – A set of data fields Template – A pattern that matches particular tuples

Provides spatiotemporal decoupling

“out”

“rout”

“in”

TuplespaceTuplespace

“in”

9MURI 2005

Implementation on TinyOS 1.1.13

Agilla 1.x is available for Mica2 and MicaZ motes 4 agents/node

Agent Injector Written in Java Remote Injection via RMI

Key Challenges: Memory:

• ROM: 54.7KB of 128KB • RAM: 3.5KB of 4KB

Message loss

10MURI 2005

Agilla 1.x Test Bed

6x9 Mica2 Mote Test Bed

Multi-hop Grid One base station

Base Station

11MURI 2005

Performance Evaluation: migration vs. remote tuple space access

Migration instructions are more reliable because of hop-by-hop acknowledgements…

…but remote tuplespace operationshave less overhead

12MURI 2005

Agilla Instruction Execution Times

Local Operations

Remote Operations

13MURI 2005

Application Experiences Fire Detection & Tracking

Presented at MURI 3-Year Review and IPSN 2005 Efficient Network Exploration

In collaboration with UCI Presented at MURI 3-Year Review

Intruder Detection and Tracking Yuling Liang’s CS 521S Class Project

Cargo Tracking In collaboration with

Robot Navigation Around Fires In collaboration with the Media Machines Lab

14MURI 2005

Intruder Detection and Tracking

Base Station

Tracker sends back a heartbeat. Base station re-deploys tracker if heartbeat goes away.

15MURI 2005

Cargo Tracking

7 million containers arrive annually into the US Impossible to check every container

Existing container security devices are limited:

•Requires line-of-sight with satellite•Low-bandwidth (six 9B msgs/day)•$500/device, $34.95/mo

16MURI 2005

AgiTrack: Cargo Tracking using Agilla

base

station

base

station

Internet

•Manifest•Security Flags

•Find Cargo•Load Manifest•Find Intrusions

17MURI 2005

Dynamic Context Discovery & Multi-Hop Network Formation

Ship

Dock

base

station

base

station

PDA

18MURI 2005

Agilla 2.0

Supports multiple base stations Allows nodes to move (physical mobility) Integrates wireless sensor networks with IP

networks

Agilla Network

Agilla Network

AgillaTuple Space

LimoneTuple Space

Limone Network

(IP)

Limone ServiceRegistry

Limone agent encapsulatesAgilla agent

19MURI 2005

Systematic Network Traversal

20MURI 2005

Robot Navigation

Mobile agents guide robot safely around the fires

21MURI 2005

Robot Navigation Videos

Without sensor network data With sensor network data

http://www.cse.wustl.edu/~bayazit/index.php?page=sensornet

22MURI 2005

System Challenges

Multi-Hop Routing No geographic routing implementation available for

Mica 2 Not enough memory on Mica2 motes for Agilla & Mint

Indoor localization Cricket motes use a different radio packet and don’t

have enough memory to run Agilla Use Cricket & Mica 2 platforms

Outdoor localization Least Squares Scaling (LSS) UIUC

23MURI 2005

Conclusions

Mobile agent middleware simplifies application deployment & increases network flexibility

Empirical results show that deploying sensor network applications via mobile agents is reliable and efficient

There are many applications for mobile agents in wireless sensor networks Fire detection Intruder detection Cargo tracking Robot navigation

24MURI 2005

Agilla URL: http://mobilab.wustl.edu/projects/agilla• Source Code• Documentation• Tutorials• Experience Reports

Thank you!