Presentazione di PowerPoint

1
European Workshop ICT and Civil Protection
current state and future scenarios
Senigallia, 18-19 June 2007
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Wireless sensors solutions for
environmental monitoring applications why?

• Advantages
• No connection problems due to distance between
  the sensor and the LWU and obstacles between them
  
• Freedom in the choice of the installation place
• Easy to connect (plug and play solution)
• Unlimited diffusion of the data (with access key)
• Fast and easy to install and to mantain (there is
  no need of qualified people to do it)

ICT and Civil Protection Senigallia,
18-19 June 2007
3
Wireless sensors solutions for
environmental monitoring applications
architecture
ICT and Civil Protection Senigallia,
18-19 June 2007
4
Wireless sensors solutions for environmental
monitoring applications protocols

• The wireless solution in the field of sensors
  presents wide sperimental and
• innovation margin. This solutions can be searched
  inside various polifunctional
• standard, that can be classified depending on the
  working area
• WPAN (Wireless Personal Area Network)
• BlueTooth (IEEE 802.15.1)
• BlueTooth 2 (IEEE 802.15.3)
• ZigBee (IEEE 802.15.4)
• sensori smart WPAN (IEEE P1451.5a)
• WUSB a basso rate (Wireless Universal Serial Bus
  su LR-WPAN, IEEE 802.15.4)
• WUSB ad alto rate (Wireless Universal Serial Bus
  su HR-WPAN, IEEE 802.15.3)
• Wireless Firewire (IEEE1394, UWB)
• WLAN (Wireless Local Area Network, IEEE 802.11)
• WiFi (IEEE 802.11b-g)
• sensori smart WLAN (IEEE P1451.5b)
• WMAN (Wireless Metropolitan Area Network, IEEE
  802.16)
• sensori smart WMAN (IEEE P1451.5c)
• WiMAX (IEEE 802.16)

ICT and Civil Protection Senigallia,
18-19 June 2007
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Wireless sensors solutions for
environmental monitoring applications

• The possible solutions, arranged on the previous
  categories, can be compared referring to the
  specific requests and the additional parameters
  principally
• Number of connecting sensor
• Cost
• Power / consumption
• Safety
• Hardiness / EMC
• Distance
• Performance (error rate)
• Compactness
• Transmission speed
• Inside the large range of possible solutions
  showed before, the choice must be restricted
  toward one of this two standards ZigBee or WUSB
  for each of them here are some of the principal
  characteristics

ICT and Civil Protection Senigallia,
18-19 June 2007
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WUSB characteristics

• Datarate 62.5 kbps max
• Star topology
• Spatial coverage from a minimum of 10m to 50m in
  open space
• Transmitted signal modulation DSSS type (Direct
  Sequence Spread Spectrum)
• Dinamic adressing of the devices
• Transmission affidability
• Low consumption (average current 90µA)
• 79 channels in ISM band at 2.4GHz, that through a
  mulplation technique of the code can be used to
  reach a maximum of 3871 simultaneous
  communications
• Duty-cycle 1
• Low unitary cost of the devices.

ICT and Civil Protection Senigallia,
18-19 June 2007
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ZigBee/802.15.4characteristics

• Datarate 250 kbps max, 20 kbps and 40kpbs
• Star topology or peer to peer topology
• Spatial coverage from a minimum of 10m to 100m in
  open space
• Transmitted signal modulation DSSS type (Direct
  Sequence Spread Spectrum)
• Dinamic adressing of the devices (till 65536
  connected nodes)
• Transmission affidability
• Low consumption (average current 40µA)
• 16 channels in ISM band at 2.4GHz, 10 channels in
  ISM band at 915MHz and one channel in the
  European band at 868MHz
• Duty-cycle lt 0.1

ICT and Civil Protection Senigallia,
18-19 June 2007
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Operating systems for wireless sensors

• The properties of a wireless sensors network
  impose the use of an operating system, that
  considers
• Small hardware dimensions and low energy
  avaliability
• High number of events in the use of sensors
  network
• Low parallelism level of the sensors network
• Need to adequate the same kind of software to
  different hardware devices
• Tolerance to damages in sensors network that work
  in critical environment

ICT and Civil Protection Senigallia,
18-19 June 2007
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Operating systems for wireless sensors

• An operating system for wireless sensors must be
  characterized from
• Simplicity it must avoid operations unuseful and
  hard working for the operating system
• Energetic saving it must turn off the hardware
  resources when not working
• Efficency it must fastly manage a large quantity
  of events to avoid losing precious information
• Low parallelism fast access to the hardware and
  low execution overhead
• Modularity it must grant reusability and
  maintenance of the software
• Failure tolerance it must support the
  development of reliable distributed solutions

ICT and Civil Protection Senigallia,
18-19 June 2007
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TinyOS

• Open source operating system for wireless sensor
  network
• Developed by Berkleys University and by the
  Intel research center (www.tinyos.net).
• TinyOS has been developed with the following
  objectives
• Reduce energy consumption, computational charge
  and memory occupation
• Support intensive contemporaneous, robust,
  efficient and modular operations requests
• The result is an operating system characterized
  by
• Reduced kernel that allows the direct access to
  the hardware
• The memory is considered as a unique and linear
  physical space, allocated at compilation time

ICT and Civil Protection Senigallia,
18-19 June 2007
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TinyOS

• TinyOS is a very small dimensions operaing system
• To satisfy the efficency requirement, TinyOS has
  been implemented following the events model.
• In the field of wireless sensors network, the
  external events based approach allows to use the
  hardware resources in the most efficient way.
• To satisfy the modularity requirement, TinyOS has
  been implemented using a components model.
• Each component present in TinyOS is an
  independent software unit provided with
  interfaces.
• The TinyOS system and its applications are
  written in NesC language.

ICT and Civil Protection Senigallia,
18-19 June 2007
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Wireless intelligent sensors- General
characteristics -

• Radio link between the sensor and the LWU (local
  web unit)
• Used frequency range ISM 2,4GHz
• The use of this particular range allows to
  operate freely without the need of licenses or
  grants dealing with the European Standards EN
  300-220-3, EN 3001-489-3 and to the
  raccomandations CEPT-ERC-REC 70-03
• Software selectable number of useful channels
  12
• Communication protocol from sensors to the Zbee
  LWU
• Transmission rate 9600bit/s
• Number of connectable sensors ? 20
• Normal polling cicle 30 minutes (programmable
  from 15 minutes to 24 hours)

ICT and Civil Protection Senigallia,
18-19 June 2007
13
Wireless intelligent sensors- General
characteristics -

• Fast polling cycle 3 minutes
• Each sensor clock interlocked with the LWU one
• Auto configuration of every sensor inside the
  LWU network
• Distance between the sensor and the LWU
• superior to 300m without obstacles between the
  terminals
• superior to 30m in presence of obstacles that
  obstruct the visibility
• Non rechargeable power batteries
• Power and voltage of the batteries depending on
  the sensor
• Battery life superior to 6/12 months depending
  on the sensor

ICT and Civil Protection Senigallia,
18-19 June 2007
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- Termoigrometer -

• Every minute, acquisition of temperature
• and relative damp values.
• Validation, through apposite algorithm,
• of the acquired values.
• Maximum and minimum values calculation,
• in the record interval.
• Temperature range 30C ? 50C
• Temperature values accuracy ?0,3C
• Range 0 ? 100
• Accuracy ? 3
• 4 batteries size C
• Absorption during measurement ? 5mA
• Stand-by absorption 100?A
• Average absorption including radio
• module ?0,5mA
• Working autonomy superior to 12 months

ICT and Civil Protection Senigallia,
18-19 June 2007
15
- Anemometer -

• Acquisition of speed values every
• 5 seconds.
• Validation, through apposite algorithm,
• of the acquired values.
• Maximum and minimum values calculation,
• in the record interval.
• Measurement range 0m/s ? 50m/s
• Measurement accuracy ? 0,5m/s
• 4 batteries size C
• Absorption during measurement ? 4mA
• Stand-by absorption 100?A
• Average absorption including radio
• module ?0,4mA
• Working autonomy superior to 12 months

ICT and Civil Protection Senigallia,
18-19 June 2007
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- Gonioanemometer -

• Acquisition of speed values every
• 5 seconds.
• Validation, through apposite algorithm,
• of the acquired values.
• Maximum and minimum values calculation,
• in the record interval.
• Measurement range 0 ? 360
• Measurement accuracy ? 2
• 4 batteries size C
• Absorption during measurement ? 2mA
• Stand-by absorption 100?A
• Average absorption including radio
• module ?0,4mA
• Working autonomy superior to 12 months

ICT and Civil Protection Senigallia,
18-19 June 2007
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- Rainfall sensor-

• Registration of the single tip and of the tipping
  
• Instant.
• Measures compensation algorithm due to the
• rain intensity.
• Measurement range 0 a 300mm/h
• Measurement accuracy ? 3
• 4 batteries size C
• Working autonomy superior to 12 months

ICT and Civil Protection Senigallia,
18-19 June 2007
18
- Ultrasonic level sensor -

• Acquisition of water level every
• 2 minutes.
• Validation, through apposite algorithm,
• of the acquired values.
• Maximum and minimum values calculation,
• in the record interval.
• Measurement range ?1cm
• Measurement accuracy 0,5m ? 6m
• 4 batteries size D
• Absorption during measurement ? 50mA
• Stand-by absorption 100?A
• Average absorption including radio
• module ?2mA
• Working autonomy superior to 6 months

ICT and Civil Protection Senigallia,
18-19 June 2007
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- LWU (local web unit) -

• The LWU picks up the data sent via radio from the
  sensors and through a web server. It sends the
  data via GPRS or UHF radio module, with a
  9600bit/s modem to the center.
• The power for Rx/Tx devices and the Web server it
  is given by a battery and a solar panel.
• Composition of the LWU
• Tx/Rx ISM module for the sensors connection
• Web server
• Radio device for the connection with the
• Access point
• Average absorption of ISM module during the
• connection with the sensor 50mA

ICT and Civil Protection Senigallia,
18-19 June 2007
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- LWU -

• Average absorption of the radio device during
  the connection with the Access Point 800mA
• Average absorption of the system 65mA
• Autonomy without sunstroke gt30gg
• The alternative modules to the radio are
• GPRS module
• Trasmitter receiver in UHF band with data
• speed trasmission 9600bit/s (GP340 data)

ICT and Civil Protection Senigallia,
18-19 June 2007