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Global Sensor Networks
A Platform for the Internet of Things
Ali Salehi,Prof. Karl Aberer
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What are Sensor Networks ?
ActuatorsSensors
Interconnected!and Actuators,Sensors,
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Properties of existing solutions
ExpensiveTo Modify
Time consuming
HireExpert(s)
People don't benefit from sensor networks.
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Motivation,
?
?
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Question : What is common ?
1. Stream of Data.2. Structure can be defined.3. Common Requirements.
Virtual Sensor
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WHAT DOES ALL THIS MEANWHAT DOES ALL THIS MEAN
Internet of Things.
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Hardware independent, any new hardware (sensors and actuators) should be integratable.
Application independent.
Light & Scalable (internet scale ; peer to peer)
Modifications MUST be very cheap and simple.
Modifications MUST be applied while system is running.
Solution,
Restarting the internet ?!!!
A Software :
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Design, Global Sensor Networks
Common data processing, management and interfacingrequirements, off the shelf.
GSN = implementation of thevirtual sensor concept and theall the listed requirements.
Multi layered architecture to be deployable on resource constrained devices.
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Simplicity, Simplicity, Simplicity (1)Email to MMS
Service (swisscom)
A ) Select Image from CameraB ) Select Temperate from MoteA
Select Camera.Image from A[window 1],B[window 10min]
where avg(temperature) >30
Ap
plicatio
n d
escriptio
n
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Control EngineersAutomatic Control Laboratory ,ETHZ
Requirements: Simplicity, Unified Abstraction.
Matlab Controller
Light &Temperature
Electricblinds
GSN
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Stream Services Develop sensor network applications :
Virtual sensors. Might produce a stream of data (service).
Buy a stream source : Hardware and/or Service (E.g., Lausanne
temperature ).
StreamSources
GSN Virtual Sensors
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Simplicity, Simplicity, Simplicity (2)
Self identifying devices (IEEE 1451).
TEDS and Virtual TEDS.
Zero-programming deployment.
TemplateVirtualSensor
TEDSNew
VirtualSensor
+ =
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High Level View of The GSN
* Uniform API for developing Sensor Network Applications.* Declarative Requirement Management.* Uniform API for exporting sensor data to the GSN. * Various protocols (interfaces) for accessing data.
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Resource Discovery
Addressing the virtual sensors : Static (e.g., socket address).Dynamic using a set of predicates :
Using a Directory Service: <predicate key=“GPS.Latitude”>46.3423</predicate> <predicate key=“Type”>temperature</predicate>
Distributed Directory Service (DDS)*:Based on P-Grid infrastructure.Each node acts as a peer in DDS.
* Not implemented yet.
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Resource Constrained Devices
Resources are allocated on demand.
Resource sharing as much as possible.
20 virtual sensors, 10% > CPU, 64MB RAM, 500 Mhz.
Requirements (e.g., Nokia 770), 32-bit processor. 64 MB Memory and/or Swap Option. 25 MB Storage.
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Wrappers, as of TodayBridge between the sensors/actuators and the GSN.
Wrappers Actuators
TinyOS 1.x SMS Service.
TinyOS 2.x Email Service.
Wise Nodes Pages Service.
TI RFID Readers (20cm)Alien Tech. Readers (20m)
Fax Service.
Wired Cameras EPuck Robots.
Networked Cameras Speaker Output (AT&T)
Generic Bluetooth Protocol
IEEE 1451 Compatibility
Generic Serial
Generic UDP
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Outcome as of today.
Successful Open Source Project.
More than 20 sensors/actuators supported.
7 Releases of the engine (Stable).
30K visitors, 600 downloads.
Users Community GNU GPL License
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WHAT DOES ALL THIS MEANWHAT DOES ALL THIS MEAN
GSN, Middleware for Internet of Things.
Q/A