Axa Assurance Maroc - Insurer Innovation Award 2024
Thesis Presentation: Web-Integrated Smart City Infrastructure
1. Web-Integrated
Smart City Infrastructure
A caching proxy for hybrid CoAP-HTTP networks.
Supervisor: Candidate:
Prof. Dr. Giovanni Malnati Francesco Corazza
Co-supervisors:
Prof. Dr. Stefano Ceri (Politecnico di Milano)
Prof. Dr. Friedemann Mattern (ETH Zürich)
Tutor:
Dipl.-Ing. Matthias Kovatch (ETH Zürich)
26 November 2012
2. Web-Integrated Smart City Infrastructure Francesco Corazza
Smart Cities?
Ningbo City, China Taipei , Taiwan
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3. Web-Integrated Smart City Infrastructure Francesco Corazza
•
1. Smart Cities and Internet: •
•
interconnected worlds •
•
• Wireless Sensor Network (WSN) The Internet of Things vision
• Spatially distributed autonomous sensors Internet of Things
• Low bandwidth, lossy, unstable medium (Trillions of nodes)
• Low energy, power, processing, faults
• IEEEE 802.15.4 – Low Rate WPAN
Fringe Internet
• Internet of Things (Billions of nodes)
• Proprietary solutions
Core Internet
• IPv6 over Low-power WPAN (6LoWPAN) (Millions of nodes)
• IP as common language
• “Things” can access standard web services
• “Things“ can be addressed from Internet
• Application-layer interconnection (Web)
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4. Web-Integrated Smart City Infrastructure Francesco Corazza
•
1. Smart Cities and Internet: •
•
RESTfy real world •
•
• Web of Things
• Web tools in real world (browser, search) Intersection originating the WoT
• Physical/virtual mashups
• REST
• Everything is a resource
• Architectural constraints
• Scalability, usability, and accessibility
• HTTP
• Constrained Application Protocol
• Designed from a subset of HTTP
• Low overhead (UDP fragmentation)
• Machine to Machine (M2M) applications
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5. Web-Integrated Smart City Infrastructure Francesco Corazza
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1. Smart Cities and Internet: •
•
CoAP (Constrained Application Protocol) •
•
• Features
• Async communication (request/response) HTTP vs. CoAP protocol stack
• Stateless reliability (confirmable/ack)
7 HTTP CoAP
• Security (CoAPS)
• Observation (native publish/subscribe) 4 TCP UDP
• Blockwise transfers (stateless large transfers)
IPv6
• Options 3 IP
6LoWPAN
• Minimum parsing complexity
• Finite number of identifiers 2 Ethernet MAC 802.15.4.5 MAC
• Caching
1 Ethernet PHY 802.15.4.5 PHY
• Freshness model
• Validation model
• Proxying
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15. Web-Integrated Smart City Infrastructure Francesco Corazza
•
3. Design the proxy: •
•
final architecture
Resources HTTP Client
HTTP Translator
CoAP Client
Resource
Cache
Abstractions Proxy Endpoint
Proxy Communicator
HTTP Translator
CoAP Stack
HTTP Stack
Servers
26
16. Web-Integrated Smart City Infrastructure Francesco Corazza
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4. Evaluation: •
•
performance assessment •
•
400
100 requests/s
Average Round Trip Time (ms)
• Emulation
350 200 requests/s
• Proxy JVM limitation
400 requests/s
• CoAP Server Virtualization 300
600 requests/s
• Test client 250
• Pre-compiled requests
• Random distribution of requests 200
• Normal distribution of resources
150
• Average of several “runs”
• Produced data 100
• Raw RTT distributions
50
• RTT/throughput trends
• CDF for RTT 0
0 200 400 600 800 1000
Request number
27