XGSN: An Open-source Semantic Sensing Middleware for the Web of Things

XGSN: An Open-source Semantic Sensing Middleware

for the Web of ThingsSome Afterthoughts

Jean-Paul Calbimonte, Sofiane Sarni, Julien Eberle, Karl AbererLSIR EPFL

Semantic Sensor Networks SSN 2014. International Semantic Web Conference ISWC 2014

Riva del Garda, 20.10.2014

@jpcik

Sensor deployments everywhereMountainsGlaciersSnow regionsSea CoastalAgriculture…

DIYMobileParticipatory

People want the data!

So what can I do with it?

• Get data from my sensors (API, web interface) • Store and archive the data• Put it online, available for download• Put it online, available for discovery and querying• Apply post-processing to the data• Combine different data sources• Use the data from an R script• More stuff…

OSPER - Swiss ExperimentOpen support platform for environmental research

Multidisciplinary research team• Real world data + problems

Facilitating research in:• Precipitation patterns in mountains• Evaporation in Africa• Return periods of Natural Hazards• Stream flows in Alpine catchments• Permafrost in the Alps

managing environmental sensor data &metadata

Platform

http://swiss-experiment.chD

ata

heterogeneous sensing devices

summarization, filtering, compression, interpolation

continuous processing, streaming, geospatial, aggregation

pattern discovery, correlation, regression

metadata management, semantics

data services, visualization, standards

acquisition

processing

querying

analysis

discovery

provision

OpenSense2global concernhighly location-dependenttime-dependent

Crowdsourcing High-Resolution Air Quality Sensing

Air Pollution

Accurate location-dependent and real-time information on air pollution is needed

Integrated air quality measurement platform

Heterogeneous devices and data Human activity assessment, lifestyle and health data

• Link high-quality and low-quality data • Integration of pure statistical models and physical

dispersion models• Better coverage through crowdsensing• Incentives for crowd data provision• Finer temporal and spatial resolutions• Utilitarian approach for trade-off between model

complexity, privacy and accuracy• Higher accuracy of pollution maps models

http://opensense.epfl.ch

Institutional stations

OpenSense infrastructure

Personal mobile sensors CrowdSense

OpenIoT FP7

Open Source Cloud solution for the Internet of Things

http://openiot.eu

Established Open-source platform for IoT

• Integrate sensors & things with cloud computing • Configure, deploy and use IoT services• Auditing/assessing privacy of IoT apps in the cloud• Semantic annotations of internet-connected objects• Energy-efficient data harvesting• Publish/subscribe for continuous processing and

sensor data filtering• Mobility of sensors and QoS aspects in IoT

https://github.com/OpenIotOrg/openiot

Use cases and validation scenariosSmart

Manufacturing Campus Guide Air MonitoringAgriculture

Sensing

The OpenIoT Architecture

Sensor data management

Semantic data management

X-GSN goes here

GSN: Global Sensor Networks

Managing sensor datasets

Publishing sensor observations

Discovery and exploration of datasets

Processing sensor time series

Open source project: Available in Github

• Open Source License• Mainly in Java• Community Support• Used in several projects

Releases available in Github

The OpenIoT Architecture

Sensor data management

Semantic data management

X-GSN goes here

Discovery & Exploitations

Request Definition & Presentation

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Everything nice if your data is also nice

Issues: here, there and everywhere

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GSN architecture

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data acquisition

storage

query processing

data access interfaces

security

preprocessing

GSN: distributed deployment

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pluggable input

pluggable output

standards?

discovery?

vocabularies?

semantics?

GSN REST interfaces: e.g JSON

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Request all sensors in this GSN instance

Standard vocabs?Semantics?

SSN Ontology, for sure

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ssn:Sensor

ssn:Platform

ssn:FeatureOfInterest

ssn:Deployment

ssn:Property

cf-prop:air_temperature

ssn:observes

ssn:onPlatform

dul:Place

dul:hasLocation

ssn:SensingDevicessn:inDeployment

ssn:MeasurementCapability

ssn:MeasurementProperty

geo:lat, geo:lng

xsd:double

ssn:hasMeasurementProperty

ssn:Accuracy

ssn:ofFeature

aws:TemperatureSensor

aws:Thermistor

ssn:Latency

dim:Temperature

qu:QuantityKind

cf-prop:soil_temperature

cf-feat:Wind

cf-feat:Surface

cf-feat:Medium

cf-feat:aircf-feat:soil

dim:VelocityOrSpeedcf-prop:wind_speedcf-prop:rainfall_rate

aws:CapacitiveBead …

…

…

Where to look for vocabs?

When do we set up the onto?

Who sets it up?http://lsm.deri.ie/resource/4039002668863045

http://lsm.deri.ie/ont/lsm.owl#unit

"Percent"

Ontologies in OpenIoT

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‘configure’ ontologieshere

But sensors and wrappers configured here

Virtual Sensors

Data in GSN through Wrappers

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Common abstractions, independent of applications, hardware

Simple integration & data correlation.

5140

GS

N

Various

Applications

Plug & Play

deployment

On-the-fly

reconfiguration

GS

N

GSN

Virtual Sensor configuration

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<virtual-sensor name="room-monitor" >

<addressing>

<predicate key="geographical">BC143</predicate>

<predicate key="usage">room monitoring</predicate>

</addressing>

<life-cycle pool-size="10" />

<output-structure>

<field name="image" type="binary:image/jpeg" />

<field name="temp" type="int" />

</output-structure>

<storage permanent="true" history-size="10h" />

<input-streams>

<input-stream name="cam">

<stream-source alias="cam" storage-size="1“ sampling-rate=“1”>

<address wrapper=“tinyos2.x">

<predicate key=“host">tinybox.epfl.ch

</predicate>

<predicate key=“port">9001</predicate>

</address>

select * from WRAPPER

</stream-source>

<stream-source alias="temperature1“

storage-size="1m“ sampling-rate=“1”>

<address wrapper="remote">

<predicate key="type">temperature</predicate>

<predicate key="geographical">BC143-N </predicate>

</address>

select AVG(temp1) as T1 from WRAPPER

</stream-source>

<stream-source alias="temperature2“

storage-size="1m“>

<address wrapper="remote">

<predicate key="type“>temperature</predicate>

<predicate key="geographical“>BC143-S </predicate>

</address>

select AVG(temp2) as T2 from WRAPPER

</stream-source>

<query>

select cam.picture as image, temperature.T1

as temp from cam, temperature1

where temperature1.T1 > 30 AND

temperature1.T1 = temperature2.T2

</query>

</input-stream>

</input-streams>

</virtual-sensor>

Some metadata is here

Sensor metadata configuration

Some available mappings

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• HTTP generic wrapper

• devices accessible via HTTP GET or POST requests, e.g., the AXIS206W wireless camera

• Serial forwarder wrapper

• enables interaction with TinyOS compatible motes (standard access in TinyOS)

• USB camera wrapper

• local USB connection.

• supports cameras with OV518 and OV511 chips.

• RFID wrapper

• access to Texas Instruments Series 6000 S6700 multi-protocol RFID readers

• Alien Technologies long range RFID reader 8950 EU.

• WiseNode wrapper

• access to WiseNode sensors (CSEM, Switzerland, http://www.csem.ch/)

• Generic UDP wrapper

• any device using the UDP protocol

• Generic serial/bluetooth wrapper

• supports sensing devices which send data through the serial port, e.g., EPuck robots, etc.

Register metadata

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If ontologies change…

If we add new types of sensors?

Do I have control over my sensor metadata?

Metadata properties

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sensorID="http://lsm.deri.ie/resource/1099207032411018"sensorName=closedsensesource=“Some source"sourceType=lausannesensorType=lausanneinformation=Air Quality Sensors from Lausanne station 1author=opensensefeature="http://lsm.deri.ie/OpenIoT/opensensefeature"fields="humidity,temperature"field.temperature.propertyName="http://lsm.deri.ie/OpenIoT/Temperature"field.temperature.unit=Cfield.humidity.propertyName="http://lsm.deri.ie/OpenIoT/Humidity"field.humidity.unit=Percentfield.co.propertyName="http://lsm.deri.ie/OpenIoT/CO"field.co.unit=PPMlatitude=46.529838longitude=6.596818

Turtle RDF registration

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<sensor/5010> rdf:type aws:CapacitiveBead,ssn:Sensor;rdfs:label "Sensor 5010";ssn:observes aws:air_temperature ;phenonet:hasSerialNumber

<sensor/5010/serial/serial2> ;ssn:onPlatform <site/narrabri/Pweather> ;ssn:ofFeature <site/narrabri/sf/sf_narrabri> ;ssn:hasMeasurementProperty

<sensor/5010/accuracy/acc_1> ;prov:wasGeneratedBy "AuthorName";DUL:hasLocation <place/location1>;lsm:hasSensorType <sensorType1>;lsm:hasSourceType "SourceType".

<sensorType1> rdfs:label "TypeName".

<sensor/5010/serial/serial2> rdf:type phenonet:SerialNumber; phenonet:hasId "5010" .

<sensor/5010> rdf:type aws:CapacitiveBead,ssn:Sensor;rdfs:label "Sensor 5010";ssn:observes aws:air_temperature ;phenonet:hasSerialNumber

<sensor/5010/serial/serial2> ;ssn:onPlatform <site/narrabri/Pweather> ;ssn:ofFeature <site/narrabri/sf/sf_narrabri> ;ssn:hasMeasurementProperty

<sensor/5010/accuracy/acc_1> ;prov:wasGeneratedBy "AuthorName";DUL:hasLocation <place/location1>;lsm:hasSensorType <sensorType1>;lsm:hasSourceType "SourceType".

<sensorType1> rdfs:label "TypeName".

<sensor/5010/serial/serial2> rdf:type phenonet:SerialNumber; phenonet:hasId "5010" .

A bit more of semantics

Need tools for this

OpenIoT Schema Editor

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Mobile sensors issues

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ssn:Sensor

ssn:FeatureOfInterest

ssn:Propertyssn:observes

ssn:SensingDevice

ssn:ofFeature

ssn:Platform

ssn:Deployment

dul:Place

dul:hasLocation

ssn:inDeployment

geo:lat, geo:lng

xsd:double

But sensors move!

‘Mobility context’

Places where the sensor is usually in…

URI issues

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• Auto-generated URIs: problematic naming

• Generate a sensor URI: templating

• Producing Duplicated Sensor registrations

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Push observations there?

Push observations

Push observations

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RDF observation annotations

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CQELS stream processing

When to store, when to stream?

A-priori knowledge of the data usage

Why Streams?

Web standardsData discoveryData sharingWeb queriesG

o W

eb

SemanticsVocabulariesData HarvestingData linkingMatchingIn

tegr

atio

n OntologiesExpressivityInferenceRule processingKnowledge basesR

eas

on

ing

Query languagesQuery answeringEfficient processingQuery Federation

Pro

cess

ing

Do we always require these?

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In Practice?

Discussion

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•Annotation in IoT• Dynamic sensor data streams• Scalability

•Ontologies & Vocabularies• Reuse, definition, policies

•OpenIoT platform• Modules available• System integration

Muchas gracias!

Jean-Paul CalbimonteLSIR EPFL

@jpcik