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1 drshin@ece.skku.edu
Introduction
Related work
2
Contents
Publish/Subscribe middleware
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Conclusion and Future works
Introduction
Objectives Research related to adaptive ontology middleware for diverse
raw data in sensor networks
Topics related to our research Context aware Ontology Middleware
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Middleware Ontology Context aware
Step 1
Step 2
Step 3
Introduction
Ontology A data model that represents a set of concepts within a domain
and the relationships between those concepts• It is used to reason about the objects within that domain
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Introduction
Context any information that can be used to characterize the situation of
entities.
Context-Awareness Seeks to deal with linking changes in the environment with
computer system
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InputInformation
OutputInformation
Context-Aware System
General context
- User situation
- Physical situation
- Computing system situation
- etc.
Introduction
Middleware The software that sits 'in the middle' between applications
working on different operating systems
Function• Support the standardized system service for diverse application
• Support environment to control diverse application
• Support the technology to efficiently use system resource
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To begin with we should develop the middleware to send diverse sensing data to user application
(Step 1)
Related work
Sensor middleware The main purpose of middleware for sensor networks
• Support the development, maintenance, deployment, and execution of sensing-based application
This includes mechanism for• Formulating complex high-level sensing task
• Communicating this task to the WSN
• Coordination of sensor nodes to split the task and distribute it to the individual sensor nodes
• Data fusion for merging the sensor readings of the individual sensor nodes into a high-level result
• Reporting the result back to the task issuer
• Etc.
Energy efficiency, robustness and scalability
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Related work
Sensor middleware modules
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User App #1
User App #2
User App #3
Context-Aware management component
USN application service management component
Meta-data management component
Sensing-data management component
Various query component
USN gateway management component
Server-side In-network
Node App #1 Node App #2 Node App #3
In-network query
component
Sensor/driver management component
Topology management component
Sensor node monitoring component
Related work
Sensor middleware modules
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Server-side (server) Description
Various query component A component to express various requirement of USN application service
Sensing-data management component
A component to efficiently store and manage sensing-data by time
USN gateway management component
A component to abstract the sensor nodes for the independent wireless communication between these nodes
USN application service management component
A component to independently assign and manage application service
Meta-data management component
A component to store information about other information
Context-Aware management component
A component to compare and analyze previous and current information for adapting them to the current user’s situation
In-network (sensor) Description
In-network query component A query process component for information sharing between sensor nodes
Topology management component
A maintenance and management component of topology in sensor networks
Sensor node monitoring component
A monitoring component on the sensor node’s resource and neighbor
Sensor/driver management component
A sensor and driver control component
Pub/Sub middleware
Asynchronous messaging paradigm where senders (publishers) of messages are not programmed to
send their messages to specific receivers (subscribers) Publisher
• Published messages are characterized into classes– Without knowledge of what (if any) subscribers there may be
Subscribers• Express interest in one or more classes, and only receive message
that are of interest– Without knowledge of what (if any) publishers there are.
Decoupling of publishers and subscribers • Allow for greater scalability and a more dynamic network topology
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Pub/Sub middleware
Publish/Subscribe architecture
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Node App #1 Node App #2 Node App #3
Publish/Subscribe middleware
TinyOS 1.x
Architecture
Radio CPU Sensor
Message management
Data management
Service #1
Service #2
Service #N
Topic Publish Subscribe
Pub/Sub middleware
Publish/Subscribe middleware module
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Publish/Subscribe middleware
Message management
Topic Transmit the local topic to server by broadcasting
Subscribe Receive the subscribe message from server
Publish Transmit the publish message related to subscribe
Data management
Topic Manage the data collected from local sensors (e.g. Temperature, Lighte.etc)
Publish Manage containing data related to the advertised topics
Services
AVG A service to average local or remote sensing data subscribed by server
SUM A service to sum local or remote sensing data subscribed by server
Pub/Sub middleware
Publish/Subscribe middleware diagram
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Pub/Sub middleware
Frequency Range
ProcessorRadio
TransceiverSerial Flash RAM
2.4Hz ISM BandAtmel ATMega
128LTI2420
Atmel At45DB41B
(512kB)4K bytes
Features
Buzzer Microphone Photoregister Thermistor
DescriptionMote/Board Connectors
Programming Port Data port
USB Programmer IRIS, MICAz MICA2 USB USB
Wireless Modules ( MPR 2400)
Sensor Board (MTS300)
Gateways (MIB520)
OS
Cygwin 1.5.12
Tinyos 1.1.13 version
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Pub/Sub middleware
1. Receive advertisement message of Node 1
2. Send the subscribe message of Node 1
3. Receive the sensing data of Node 1
4. Receive advertisement message of Node 2
5. Send the subscribe message of Node 2
6. Receive the sensing data of Node 1 & Node 2
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ADV (Node 1)
ADV (Node 1)
SUB(App #1)
PUB(Node 1)
PUB
(Node 1 & 2)
ADV(Node 2)
SUB(App #2)
We implemented the publish/subscribe middleware It is located on sensor nodes between TinyOS and application It communicated by message (message-oriented
communication) User application can select the specific node for collecting
sensing-data
Future work Server-side
• Various query component
In-network• Topology management component
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Thank you
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