ATSN 2009

Towards an Extensible Agent-based Middleware forSensor Networks and RFID Systems

Dirk BadeUniversity of Hamburg, Germany

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #2

Overview

• Preface

• Introduction

• Challenges

• Proposed Solution▪ Application Scenario

▪ Middleware Architecture

▪ Implementation

• Discussion

• Conclusion and Future Work

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #3

data distributionnetwork

pro-cessing

pro-cessing

pro-cessing

sensor network

data distributionnetwork

pro-cessing

pro-cessing

pro-cessing

sensor network

Preface

Different Shades of Middleware▪ Sensor Network Middleware

• supports development, maintenance, deployment, execution of sensing-based applications

• focuses on e.g. power & topology management, data transmission & aggregation inside the network

▪ Middleware beyond Sensor Networks• high-level processing & distribution of sensor data

considered asblack box

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #4

Motivation

Sensor Networks & RFID Systems…▪ Although hyped, still in an early state of adoption

▪ High investments, few standards, missing killer applications

▪ Several projects already realized• Designed for a special purpose

• Not interoperable

… will once become widespread▪ More experience with technologies

▪ New emerging requirements

Standards and best-practices will evolve Frequent redesigns of applications & frameworks

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #5

Robustness

Adaptivity

Flexibility

Openness

Heterogeneity

Scalability

Challenges

The Software-Engineering Perspective▪ Evolution of standards and best-practices requires

well designed software infrastructures

▪ Avoiding a Software-Engineering Nightmare

General, non-functional design-goals for a Sensor Network Middleware

• Tolerance towards failures, overloading

• Adaptation of processing to changing conditions

• Deployment in different scales

• Middleware shall be extensible and in parts exchangeable

• Support for different device- and data types

• Deal with drastically increasing loads

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #6

Proposed Solution

Agent-based Event Stream Processing Middleware▪ Agents as …

• design-paradigm for complex distributed processing

• building blocks for different functional roles

▪ Agents are able to …• cope with environmental dynamics

• coordinate among themselves by (a)synchronous message exchangefollowing standardized communication patterns

• exhibit different behaviors according to their context

▪ Event Stream Processing allows to …• efficiently process multiple streams of event data (e.g. from WSN)

• identify meaningful events and complex patterns

• correlate & abstract events to create Application Level Events

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #7

High Level View

ApplicationApplicationApplication

Event ProcessingMiddleware

register

ALE

· Filter· Group· Store· Enrich

· Transform· Aggregate · Create ALE· ...

Tasks

WSN

Base station

RFID

Reader

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #8

Smart Container Monitoring▪ Trading company expects to receive a pallet with TV devices

• Pallet is packed in a Smart Container equipped with several sensors

• Once the container is unpacked, sensor logs are read

• If sensor values exceed a threshold, a mechanic is called to check

▪ States of interest are …• Pallet does not arrive in time

• Pallet arrived, but sensor values indicate possible damage

• Pallet arrived, everything is OK.

▪ Trading Company registers states of interests and information is pushed to the TC once a state is achieved no pulling required

Application Scenario

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #9

Architecture

Net

wor

k E

dge

Net

wor

k La

yer

App

licat

ion

Laye

r

Connector

InfrastructureManagement

Low-Level Event Filter

High-Level Event Filter

ApplicationApplicationApplication

group, aggregatetranslate, etc.

get description,ontology, position, etc.

· Create Complex Event Pattern· Create Processing Workflow· Generate Simulation Data

ALEregister

RFIDWSNBase station

Reader

Coordinator

Monitoring/Reporting

EventGenerator

SELECT * FROM MyEventWHERE id BETWEEN x AND y AND (overallacc > 5 OR humidity > 80 OR temperature > 50)+

aggregatemax(temperature)

getInfofrom(warehouseIS, field:containerLog, of:RFID)

getInfofrom(EPCIS@xyz, field:owner,of:RFID)

storeinto(damageDB)

transformto(myProprietaryFormat)use(myAgent@tradingcorp.com)

+

groupwin:time(5s)by(id)

Processing WorkflowComplex Event Pattern

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #10

Jadex Event Stream Processing Architecture (JESPA)▪ Core infrastructure has already been implemented

▪ Network Edge • currently supports SunSPOTs, NFC Mobiles, and MagicMap

▪ Network Layer• Lightweight (and BDI-)Agents running on Jadex v2

• HLEF powered by Esper CEP Runtime

▪ Application Layer• Simple Event Generators

• MagicTracker, an Integration of JESPA with MagicMap

Implementation

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #11

Towards meeting the non-functional design-goals▪ Abilities of agents allow different ways to achieve their goals.

▪ Agents are loosely coupled.

▪ Dynamic binding achieved by federated yellow pages.

▪ Functional changes may be handled by injecting or replacing agent types.

▪ Most middleware components are optional

▪ Lightweight agents used for simple tasks, BDI-agents for more sophisticated ones.

▪ Different event sources, data formats and processing devices supported

▪ Processing of events may be easily distributed and parallelized

▪ Security not considered yet

Discussion

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #12

Conclusion & Future Work

Conclusion▪ WSNs more widely deployed, post-WSN data processing more important

▪ Challenging design of event-processing middlewares as standards, requirements and best-practices will change.

▪ Agent-based ESP shall meet these challenges.

▪ JESPA-Prototype incorporates agent-based ESP

Future Work▪ Push the implementation

▪ Develop Monitoring Tools and Event Generators

▪ Foster application integration

Towards an Extensible Agent-based Middleware for Sensor Networks and RFID Systems #13

Thank You

Questions ?

Dirk Bade

bade@informatik.uni-hamburg.de