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JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
MESH NETWORKING
LABORATORY OF TELECOMMUNICATION
S
George SergiadisAssociate Professor
ARISTOTLE UNIVERSITY OF THESSALONIKI GREECE
SCHOOL OF ELECTRICAL ENGINEERING DEPARTMENT OF TELECOMMUNICATIONS
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Characteristics of the mesh networks
• Wireless by definition, infrastructure independent
• Formed in a spontaneous way, few to plan
• New nodes become routers to expand the network, scalable system
• Not only for internet access
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
THE FAB LAB SCOPE
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
A TYPICAL urban MESH
Source: Microsoft Research
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
The announced Urban Mesh
A Spanish firm is to sell subsidized routers as part of a plan to turn domestic wi-fi networks into public hotspots. Fon will sell wi-fi routers, which allow people to surf the net wirelessly, for $5 The company, which has financial backing from Google and Skype, aims to create public wi-fi networks street by street across the US and Europe.
Tuesday, 27 June 2006
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
“Africa Calling” – a highway to follow
The number of mobile subscribers in 30 sub-Saharan African countries, not including South Africa, rose from zero in 1994 to more than 82 million in late
2004
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Rural mesh model - main components
Hardware:•Routers•Antennas, cables•Power supplies - Solar •Structural solutions
Software:•Networking and dynamic multihop routing•QOS control•Management•Security and privacy
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Routers
• Many vendors• Many low cost solutions from
25 to 60 US $, but• Most of them are not suitable
for efficient rural meshes with few gateway points
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Mesh network Protocols
• Dynamic rerouting
• Efficient package management
• Additional services
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Antennas
Price: $349.90
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Fab Lab mesh network approach
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Routers on trial
• Roofnet, an unplanned, multiroute mesh network developed at MIT's Computer Science and Artificial Intelligence Laboratory
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Fab Lab WiFi Antenna Projects
Target:
• Very low cost, 1 or 2 US $
• Low manufacturing sensitivity
• Fab Lab easily reproducible, by unskilled “Fablabers”, using the Fab Lab tools
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Fab Lab WiFi Antenna Projects
Glass Antennas:
1. Quasi-isotropic antennas, mostly for interior use
2. Arrays for higher gain, for internal or low distance external use
3. Corner reflector antennas for point to point longer distance links
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Glass Antenna “Ingredients”
• Window Glass• Self adhesive cooper• CAD file• Flexible low-loss cable, or no
cable
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
“Isotropic” Antennas
Gain 3 dbi
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Higher gain Arrays
Directivity 1200 H / 300 V- Gain 9 dbi
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Corner reflector antennas
Directivity 600 H / 300 V - Gain 12 dbi
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Very high gain systems New approaches
• Planar structure • Gain >20 dbi• Low cost – glass dielectric• Higher frequencies ( 5 GHz)
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Very high gain systems New approaches
Planar structure - Gain >20 dbi
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Potential contribution of the mesh networks, especially in
developing countries
• In business prosperity
• In employment
• In information spread
• In medical services
• In distance learning
• In natural disaster management
• Even in politics and democracy protection
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Conclusions
• Fab Lab reduces dramatically the cost of the mesh networking by producing the most expensive components, instead of buying them
• Fab Lab plans to design and manufacture also other expensive parts of the supporting infrastructure, by implementing its collective know-how
JUNE 2006 SYMPOSIUM ON DIGITAL FABRICATION PRETORIA
Thank you for your attention
LABORATORY OF TELECOMMUNICATION
S
George SergiadisAssociate Professor
ARISTOTLE UNIVERSITY OF THESSALONIKI GREECE
SCHOOL OF ELECTRICAL ENGINEERING DEPARTMENT OF TELECOMMUNICATIONS