APAN 29th Meeting - Sensor Network Workshop

Toward a Federated Framework
for Sensor Overlay NetworkSusumu Takeuchi
National Institute of Information andCommunications Technologygy (NICT),(), Japanp

Agenda• Definition of Sensor Network and Sensor
Network Federation• Proposal of a Federated Framework forFederation2

Background• IP‐based sensors are popularized– Weather
h station, wirelesslsensor networkk thathincludes tiny sensor nodes etc. is available• Wired sensors tend to have many functions,• whereas wireless sensors tend to be simple and a wired
gateway noded collectsllsensing data
dffromthem.
hGateway nodeSensor node(mote)

Weather station

Wireless Sensor Network (WSN)3

Sensor Networks as Infrastructure• Sensor Networks (SNs) are an essential infrastructurein the ubiquitous/pervasive environment
Disaster Management

Traffic Control

Facility Management

Weather Observation

4

Needs of Sensor Network Federation• Ubiquitous/pervasive services require sensing
d t as muchdata
h as possibleibl– Various kinds of many sensors will enable the services
to estimate users’ context through these sensing data
– Observing over wide‐area and for a long period will
enable to analyze world‐scale phenomenon• However, deploying
p y g and managing
g g SNs requiresqan enormous costFederation of SNs is inadequate (= utilizingsensing data between different SNs)
5

What is a “Sensor Network”?
• WSN is a form of SN, but not all– Sensors thath are connected
d in theh same mannerand behaves like a chunk of the sensors will bealso
l called
ll d as a Sensor Network,
k even iff they
h areconnected only by wireÎ SN should be a concept that multiple sensors
form a network and collect sensing dataInternetSensor Network ?

6

Basic Unit of SN: Sensor Network Unit
• Definition of a Sensor Network– A SN = one or more Sensor
SNNetworktkU
Unitsit (SNU(SNUs))– A SNU is a group of sensor(s) that has ONLY ONE
gatewaytnode,d andd MAY hhave sensor nodesd (motes)( t )• Gateway node MUST be accessible from others via network#≥1Sensor
NetworkConcept=1SNU

Gateway
Node

SNU

GatewayNode≥01 SNUSensor
NodeSensor
node

1 SNU

Physical devices
7Federation of Sensor Network (1/2)
Federation among heterogeneous(variousarchitectures)) SNUs
(Collaboration among homogeneous(single architecture) SNUs

SNU

SNU

SNU

SNU
SNU

SNU

SNU

Federated SN
Collaborated SN
Independent SN (=SNU)

Federation steps

8Federation of Sensor Network (2/2)
Ongoing Testbeds

Live E! on PIAX (JP)X‐Sensor version 2 (JP)Live E!, X‐Sensor (JP)IP‐USN ((KR))
CitySense (US)

Dawn of SNs

IndependentSN• Ad‐hoc WSN(ZigBee/WiFi)

Federated
Framework

FederatedSN
CollaboratedSN• Limited‐areaor purposep• Specificoperator• Monitoring
middleware• Extractingmeaning forvarious
purposes• Variousoperators• Loosely‐
coupledframework
9Agenda• Definition of Sensor Network and Sensor
Network Federation• Proposal of a Federated Framework forFederation

10

Our attitude toward Sensor Network Federation
Application (developers/users)• Intelligent services that utilize sensing data
Data Sharingg Platform for Sensor Network Federation• Management platform for storing, aggregating, andretrieving of sensing data
Standard for Sensor Network Federation• Access method
h d andd policyl eachh ffor sensor networkk• Metadata for sensor specification and sensing dataSensor Network (physical)• Wireless Sensor Network, Sensor Network Testbed

11Sensor Overlay Networks• SNs should be federated in loosely‐coupled P2P
management architecture– Each SN is managed by a different organization, sosensing data should be mutually transferred to share
Applications / Services
Real‐time
predictions

Content
Discovery

Statistical
Analysis

Distributed
Processing

MessagingContext‐aware
Contents

Sensor data processing

Sensor Overlay Networks
Overlay networks suitable for type of sensor data,
data services

L2/L3 NetworksIndoor
Sensors / Actuators

Wearable Sensors
Medical Sensors

Sensor NetworksSensorSe
so Networks
et o sSensors on Transportations
12

Requirements for SONs to Federate (1/2)• Interoperability between heterogeneous SNs– Difference
ffoff management policy
l off eachhddomain• Owner of each SN wants to manage their sensing datawithh theirh own customization andd management policylat their own timing– DifferenceDiff
off specifications
ifi ti• Specification of data type, observation method, accessmethod,th d datad t managementt method
th d etc.
t isi nott thethsame between the productsStandard of the description of access policy andmetadata of sensing data/method is required13

Requirements for SONs to Federate (2/2)• Data management for distributed sensing data–N
No one manages th
the entire
ti off SN
SNs, so th
thatt sensingidata is distributed in each SN
1. Sustainability (maintainability and scalability)•

Tolerate unstable situations (Churn(Churn‐‐Resilient)

2. Scalable data retrieval•

Handle various kinds of retrieval methods ((e.g.,g , location‐location‐based retrieval) to the massive sensors

3. Efficient data aggregation•Avoid collecting all raw sensing data by aggregating (e.g.,max, min, or average value of a certain area)

14

PIAX: P2P Interactive Agent eXtensions• Java‐based platform that integrates:– Multiple
M lti l P2P overlay
l didiscovery ffunctions
ti– Mobile agent features
Navigation
Streaming

Reputation
Sharing

Shopping
Assistant

Recommendation

Various ubiquitous applications
Agents

PIAX‐ Java‐based agent platform ‐zz

Multi‐Overlay
Discovery
MessagingFlexible Computing
by Mobile Agents

Scalable Messaging
by P2P Overlay

Peer

http://www.piax.org/Profiles
Reputations
SensorsContentsDevicesUsers

15

PIAX Structure and Features
Flexible and loose coupling of different services

Auth, Secure Su
upportWebService...

LL
LL‐‐NNett

AgentsGeographical retrieval

Discovery Messaging

DHT
Key‐value store

Multi‐‐OverlayMulti

DOLR

Overlay Transport
plug‐‐inplug

Physical Network

Application‐layer multicast
Flooding
Any kind of searches...

Concealing heterogeneity and complexity

Scalable hhandling oof enormo
ous data anda nodess

Agent library‐ File sharing‐ Location‐dependent contents‐ Sensor handlingg‐ RDF DB

16

PIAX‐based Sensor Overlay Network Platform• PIAX can support scalable data management onFederated SNs
1. Sustainability• Sensor agent platform and hybrid overlay network will help
to tolerate unstable situations

2. Scalable data retrieval• Structured overlays and multiple overlay networks handlingwill help to handle distributed sensing data efficiently

3. Efficient
ffd
data aggregation• Distributed data fusion by overlay roaming agents will help
to avoid collecting all raw sensing data

Ongoing projects: Live E! on PIAX, X‐
X‐Sensor v217

Live E! ProjectDisasterManagement

Education /AgricultureScienceMulti‐Attributesearchlive‐e‐wrapper(wrapper.)Live E! onPIAXDelay Tolerant
DelaNetwork

In‐Network
Data Processing

live‐e‐root (.)

Sensor &Overlay

weather.twnic(tw.)

live‐e.coe.phuket(psu.)

live‐e2.hongo (jp.)
live‐e.lru.ac.th(lru.)

livee.niu.edu.tw(niu.tw.)

Facility
Management

Multi‐Domain
SensorNetworking

Hadyal
(IPV6‐CNR‐HDY.psu.)

live‐e.kmd(kmd.jp.)

live‐e2.naist(nara.jp.)

Embeddedgateway

18

Live E! on PIAX
• Developed an agent for enabling other PIAX agents to connect Live E! sensor
stations by SOAP protocol
PIAX Overlay Network

Live E! Agent on PIAXWeb I/FSOAP
PortBrowse deployed sensors
on Web browser

Web I/FSOAP

20 PIAX Peers with Live E! sensors…

SSensor Data
D tStorage

Li E! WLive
Weatherth SSensor
Station
SOAP I/F
Sensors:‐ Temperature‐ Humidity‐ Raindrop‐ Wind speed etc.

19

X‐Sensor version 2 (based on PIAX)
X-Sensor

MultI-WSN Testbed

Users
U
Testbed Server
Gateway

DB

DBDB
DBDB

DBSensor Network20

Towards Sensor Overlay Network Platform
Application

ContinuousQuery

Sequence oftransformed datarevisedsourceaggregatedsourcetransformed
sourcerule‐based
deduction

Sensor Overlay Network Platform
Storage/Archive for sensing data
Sequenceqofsensing data

SSensor
NNetworktkUUnitit

Virtual Sensor

C ll b t d SN 1
Collaborated

C ll b t d SN 2
Collaborated
21

Conclusion• Sensor Networks– Essential infrastructure for ubiquitous orpervasive environment– Should be federated for utilizing sensing data
• Since federation is unanticipated utilization of sensing
d t loosely‐coupled
data,lll d framework
fk willill bbe requiredi d• Sensor Overlay Network Platform– Loosely‐coupled framework “PIAX” will realize anefficient SON Platform• Provide significant deduced data that satisfies versatileneeds of high‐level applications through federated SNs22