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Building Pervasive Computing Applications on Sensor Networks

Rutgers, The State University of New Jerseywww.winlab.rutgers.edu

2IAB, May 13, 2004

Introduction: Sensor Networks

GlobalInternet(~2000)

Cell PhonesEverywhere

(~2000)

Telecom

Information Tech

DigitalMedia

Convergence(2000-2010)

Internet + Telecom

The Physical World virtualized via sensors & actuators

Global Internet fordata & telecom

The Virtual World

Wireless Sensor Nets

PervasiveComputing

(2015-)

datacontrol

3IAB, May 13, 2004

Future Wireless: Pervasive Systems

Mobile Internet (IP-based)

Overlay Pervasive Network Services

Compute & StorageServers

User interfaces forinformation & control

Ad-Hoc Sensor Net A

Ad-Hoc Sensor Net B

Sensor net/IP gatewayGW

3G/4GBTS

PervasiveApplication

Agents

Relay Node

Virtualized Physical WorldObject or Event

Sensor/Actuator

4IAB, May 13, 2004

(Frictionless Capitalism)**2 Find goods and services on your PDA as you walk through town Walk into your dept store and pick up what you need (no cashier!)

“Smart” Transportation systems get routed around traffic jams in real-time receive collision avoidance feedback, augmented reality displays be guided to an open parking spot in a busy garage

Airport logistics and security Walk on to your plane (except for physical security check) Find your (lost) bags via RFID sensors Airport authorities can screen passenger flows and check for unusual patterns

Smart office or home Search for physical objects, documents, books Migrate your electronic media and documents between devices Maintain a “lifelog” that stores a history of events by location know where your co-workers and family members are

Future Wireless: Pervasive Applications

5IAB, May 13, 2004

Sensors Tiny, low-power, integrated wireless sensors (hardware) Embedded OS and networking capabilities (software)

Ad-hoc wireless networks Self-organizing sensor networks Scalable, capable of organic growth Interface to existing 3G/4G cellular and WLAN Power efficient operation Congestion control

Pervasive computing software Dynamic binding of application agents and sensors Real-time orchestration of sensor net resources Robust, secure and failsafe systems Programming paradigm for sensor networks

Augmented reality, new displays, robotics, control, information processing...

Future Wireless: Key Technologies for Pervasive Systems

emerging computer hardwarecategory, optimized for size/power

new type of wireless network withoutplanning or central control

fundamentally different software model- not TCP/IP Windows or Unix!!

...beyond the scope of this talk

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Enabling Technologies for Pervasive Systems

7IAB, May 13, 2004

Integrated sensor/actuator + low-power microprocessor + radio

Single chip or compact moduleWireless networkingEnergy efficient design

Applications of sensors include:Verticals: factory automation, security, military, logistics, transportation, ..Horizontal market: smart office, home pervasive computingIntegrated wireless sensors are the “next microprocessor”...

MIT DVS

Crossbow Sensor

UC Berkeley MOTE

Sensor Technology: Hardware

8IAB, May 13, 2004

Sensor Technology: MUSE Prototype “Multimodal” wireless sensor hardware being developed with

NJCST funding... novel ZnO materials for tunable sensors integration with low-power wireless transceiver designs focus on an integrated system-on-package or system-on-chip integrated ad-hoc networking software (as outlined earlier) sensor applications, including medical heart monitors, etc.

Sensor Device

Modem, CPU, etc

RF

Sensor RF

Modem/CPU

ZnO SAW filter,MEMS, etc.

CMOSchip

MultimodalZnO device

Reduced functionality,optimized for low powerconsumption…

Embedded ad-hocwireless net software

2002-04 target: Multi-chip module for sub-802.11b Early medical applications at UMDNJ

2005-06 target: Single chip prototype Pre-commercial applications w/ partners

9IAB, May 13, 2004

Sensor Technology: Multimodal ZnO device

“Tunable” ZnO sensor developed

by Prof. Y. Lu’s group Can be “reset” to increase sensitivity, e.g. in

liquids or gas Dual mode (acoustic and UV optic) Applicable to variety of sensing needs

Gate voltageinput

REF.

2DEGmesa

SAWIDT

2DEGGround

Sensing device with chemicallyselective receptor coating

Sensoroutput

Mixer

2DEGmesa

Courtesy of: Prof Y. Lu,Rutgers U

10IAB, May 13, 2004

Sensor Networking: Congestion Alleviation Resource control schemes to alleviate transient congestions in

sensor networks Transient congestions are common Throttling traffic is not always an option (e.g., an heart emergency generates a large volume

of data within a short time frame) Sensor networks have elastic path capacity (e.g., variable transmission power, directional

antenna, etc) We can also use multiple routing paths to guarantee reliable event delivery Timely and accurate congestion level monitoring is the key

11IAB, May 13, 2004

Pervasive Computing: Software Model Ubiquitous or pervasive computing scenarios require a

fundamentally new software model (…not TCP/IP or web!!): Large number of context-dependent sources/sensors with unknown IP address Content-driven networking (…not like TCP/IP client-server!) Distributed, collaborative computing between “sensor clusters” Varying wireless connectivity and resource levels

Pervasive/UbiquitousComputing SoftwareModel

Pervasive Computing ApplicationPervasive Computing Application

Agent 2Agent 1

Agent 3

SensorCluster A

SensorCluster B

Run-timeEnvironment(network OS)

ResourceDiscovery

Ad-hoc Routing

OS/ProcessScheduling

Overlay Network for Dynamic Agent <-> Sensor

Association

12IAB, May 13, 2004

Pervasive Computing: System Model

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Sensors & Actuators

HierarchicalAd-Hoc Data Network

Content Network

Autonomous AgentsAffinityGroups

Courtesy of Prof. Max Ott

13IAB, May 13, 2004

Self Organizing Overlay

Content Network

Discovery/Messaging(Content-DHT/ Associative Rendezvous)

NeTS Applications (Autonomic Living, Ad hoc Control)

Opportunistic Interactions

Coordinate Flows

Ad Hoc RoutingSelf Configuration

OrbitTestbed

MeteorMiddlewareStack

ProgrammingModel

Security:

Ont

olog

y, T

axon

omy

Authorization

Authentication

Trust

Software Model: Pervasive Computing Stack

Wireless/Wired Infrastructure

Prof. Manish Parashar: Programming Model & Resource Discovery

14IAB, May 13, 2004

Pervasive Computing: Content Routing

“Content routing” method for association between sensor devices, end-users and application programs

Use of XML content multicast to dynamically find consumer/producer match XML multicast can be implemented as an overlay network on IP tunnels

Sensorcontentmulticast

data

XMLdescriptor

XM

L In

tere

st

Pro

file

XM

L

data

ApplicationPrograms

End-userdevices

NetworkInfrastructure

Radio ForwardingNode

Storage

Routing

Concept of Using Content Multicast for Data-Centric Software Model

15IAB, May 13, 2004

Pervasive Computing: Process Orchestration Programming ad hoc control systems – Coordinated Flows

Dynamic binding of application with sensors & actuators Orchestration of computing and network resources in real-time

Campus Parking Service

Data Center

Check registration,Deduct parking fee

Allocate closest available space

Check parking space availability

Incoming Car ( check ID: Registered student/faculty/staff, guest reservation? Fee

deduction)

Look for parking space: subscribe (plate-num, car-type, IAB guest)

Look for parking space subscribe (plate-num, car-type, student)

Monitorincoming car

Monitoravailable space

Parking Center

courtesy of Prof. Manish Parashar

16IAB, May 13, 2004

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Micro-level

Cluster interface

Pervasive Computing Platform: Scheduling & Network OS

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Micro-level

Cluster interface

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Micro-level

Cluster interface

Cluster I:• A cluster is formed because each sensor group provides certain data or functionality that is necessary to perform the specified task.•A sensor group can participate in multiple clusters•Work must be dynamically assigned to each group based on everyone’s energy budget, load, etc. •Each sensor group should schedule its work for different clusters according to other members in these clusters.

Micro-level scheduling issues:

• which sensor nodes should be active while others sleep?

• which sensor nodes should be sending back their readings?

• how to split a task between a group of sensor nodes?

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