11

Distributed Middleware for Container Transport: Lessons

Learned (Klaas Thoelen, Sam Michiels, Wouter Joosen)

7th MiNEMA Workshop August 21, 2008 - Lappeenranta, Finland

2

Context

• Authorized Economic Operator

• Wireless Sensor Networks (WSNs) can help to automate the supply chain

• Heterogenic, dynamic and mobile WSNs need middleware support

3

Overview

Context

1. Scope

2. Middleware Architecture

3. Prototype implementation

4. Discussiona. EPC Network

b. 6LoWPAN

5. Conclusion

4

Scope

• 1 company divided over multiple sites:• harbor dock, airport terminal, warehouse, …

• Each site deploys a WSN

• Different sites - different WSNs

• Central database: used for transport and resource planning

5

Challenges

1. End-to-end interoperability

2. External data exchange

3. Heterogeneity of data and messaging formats

4. Intermittent network connection of sensor nodes

5. Inter-network mobility of sensor nodes

6

Overview

Context

1. Scope

2. Middleware Architecture

3. Prototype

4. Discussiona. EPC Network

b. 6LoWPAN

5. Conclusion

7

Distributed Middleware

• Distributed: multi-tiered

• Middleware: vertical set of service layersWSN Gateway Backend Internet

App. Specific Services

Distribution Services

Common Services

Application

WarehouseData Base

ServerApplication

Base station

WSN Gateway Backend

Web Service

Internet

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Warehouse

Data Base

ServerApplication

Base station

WSN Gateway Backend

Harbor dock

Base station

Internet

Sensing AggregationAggregation

App. SpecificServices

Distribution Services

Common Services

ApplicationMonitoring Monitoring Monitoring

Persistence

9Challenge 1: End-to-end interoperability

Warehouse

Data Base

ServerApplication

Base station

WSN Gateway Backend

Harbor dock

Base station

Internet

Sensing AggregationAggregation

App. SpecificServices

Distribution Services

Common Services

Reliable Messaging Reliable Messaging Message queue Message queue

ApplicationMonitoring Monitoring Monitoring

Persistence

10Challenge 2: External data exchange

Warehouse

Data Base

ServerApplication

Base station

WSN Gateway Backend

Harbor dock

Base station

Web Service

Internet

Sensing AggregationAggregation

App. SpecificServices

Distribution Services

Common Services

Reliable Messaging Reliable Messaging Message queue Message queue

ApplicationMonitoring Monitoring Monitoring

Persistence

11Challenge 3: Heterogeneity of data and messaging formats

Warehouse

Data Base

ServerApplication

Base station

WSN Gateway Backend

Harbor dock

Base station

Web Service

Internet

Sensing Conversion AggregationAggregation

App. SpecificServices

Distribution Services

Common Services

Reliable Messaging Reliable Messaging Message queue Message queue

ApplicationMonitoring Monitoring Monitoring

Persistence

12Challenge 4: Intermittent network connection of sensor nodes

Warehouse

Data Base

ServerApplication

Base station

WSN Gateway Backend

Harbor dock

Base station

Web Service

Internet

Sensing Conversion AggregationAggregation

Caching

App. SpecificServices

Distribution Services

Common Services

Reliable Messaging Reliable Messaging Message queue Message queue

Connectivity

ApplicationMonitoring Monitoring Monitoring

Persistence

Advertising

13Challenge 5: Inter-network mobility of sensor nodes

Warehouse

Data Base

ServerApplication

Base station

WSN Gateway Backend

Harbor dock

Base station

Web Service

Internet

Sensing Conversion AggregationAggregation

Caching

App. SpecificServices

Distribution Services

Common Services

Reliable Messaging Reliable Messaging Message queue Message queue

AdvertisingConnectivity

ApplicationMonitoring Monitoring Monitoring

Persistence

14

Warehouse

Data Base

ServerApplication

Base station

WSN Gateway Backend

Harbor dock

Base station

Web Service

Internet

Sensing RSSI measurement Conversion AggregationLocalizationAggregation

Caching

App. SpecificServices

Distribution Services

Common Services

Encryption Logging Encryption Authentication Logging Authentication Logging Persistence

Reliable Messaging Reliable Messaging Message queue Message queue

AdvertisingConnectivity

ApplicationMonitoring Monitoring Monitoring

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Overview

Context

1. Scope

2. Middleware Architecture

3. Prototype

4. Discussiona. EPC Network

b. 6LoWPAN

5. Conclusion

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Prototype

Site A

Site Z

Base station

Derby DB

Java EEApplication

GatewayJava EE

App. Client

Web ServiceJAX-WS

Base station

GatewayJava EE

App. Client

WSN Gateway Backend Internet

GlassFishJMS

JMS

17

Overview

Context

1. Scope

2. Middleware Architecture

3. Prototype

4. Discussiona. EPC Network

b. 6LoWPAN

5. Conclusion

18

Discussion

• More realistic: server & database per site

Harbor dock

Warehouse

Base station

Data Base

ServerApplication Web Service

Base station

WSN Gateway Backend Internet

Data Base

ServerApplication Web Service

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EPC Network

• Architectural framework for an integrated supply chain using RFID technology

• EPC = Electronic Product Code – Unique identifier of an object– Stored in RFID tags– a key to retrieve information about this object

EPC: 01 . 0000A89 . 00016F . 000169DC0

Header EPC Manager

Object Class

Serial Number

URL: 00016F.0000A89.sgtin.id.onsepc.com

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EPC Network

Based on figure in ‘Enhancing Information Flow in a Retail Supply Chain Using RFID and the EPC Network: A Proof-of-Concept Approach’ by S.F. Wamba and H. Boeck in JTAER Vol.3 Issue 1

RFID readers

EPC Middleware

EPC-IS

Data Base

Enterprise Applications

Local ONS

Root ONS

RFID readers

EPC Middleware

EPC-IS

Data Base

Enterprise Applications

Local ONS

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EPC Network

Based on figure in ‘Enhancing Information Flow in a Retail Supply Chain Using RFID and the EPC Network: A Proof-of-Concept Approach’ by S.F. Wamba and H. Boeck in JTAER Vol.3 Issue 1

RFID readers

EPC Middleware

EPC-IS

Data Base

Enterprise Applications

Local ONS

Root ONS

WSN

Gateway

Backend Server

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EPC Network

• Object Name System standard still in progress:– retrieval of information at all forwarders involved– instance level data

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Overview

Context

1. Scope

2. Middleware Architecture

3. Prototype

4. Discussiona. EPC Network

b. 6LoWPAN

5. Conclusion

24

Discussion

• What about direct querying an individual sensor node?– Either leverage on ONS– Or exploit the possibilities provided by IPv6

• IPv6:– Larger address space (128 bits instead of 32 bits)– Better support for mobility– But considered too memory- and bandwidth intensive

for WSNs!!!

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6LoWPAN• Extends IPv6 to Low power Wireless

Personal Area Networks

IEEE802.15.4 PHY layer

IEEE802.15.4 MAC layer

6LoWPAN Adaptation layer

IPv6

UDP/TCP/...

Default in WSNs(TinyOS, Sun SPOTS, ...)

By default too memory- and bandwidth-intensive

for WSNsEnables efficient transmission

of IPv6 datagrams over 802.15.4 links

• By providing: - Header compression

- Fragmentation

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6LoWPAN

TCP/UDP

6LoWPAN

WSN Gateway Backend/Internet

Application

Transport

Network

PHY + MAC

IPv6

TCP/UDP

802.3

Middleware + App

proprietary

proprietary

802.15.4

Middleware + App

proprietary

proprietary

802.15.4

Middleware + App

IPv6

TCP/UDP

802.3

Application

Transport

Network

PHY + MAC

IPv6

TCP/UDP

802.3

Middleware + App

IPv6

802.15.4802.15.4

Middleware + App

IPv6

802.3

6LoWPANIPv6

End-node reachability without proxy gateway

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Overview

Context

1. Scope

2. Middleware Architecture

3. Prototype

4. Discussiona. EPC Network

b. 6LoWPAN

5. Conclusion

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Conclusion

End-to-end middleware supporting monitoring of transport containers:

– Still far from trivial: heterogeneity (WSN, gateways, backend), resource-constraints of sensor nodes

– Feasible: using state-of-the-art software components, through initiatives like EPC Network and 6LoWPAN and new generation of sensor nodes

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Questions?

Thank you!