Title: monitoring/controlling critical physical infra-structures with sensor networks
1monitoring/controlling critical physical
infra-structures with sensor networks
- Mário Alves (mjf_at_isep.ipp.pt)
- Encontro com a Ciência
- Lisbon 3/JUL/2008
2CISTER/IPP-HURRAY snapshot
- FCT Research Unit 608
- rated Excellent (2004-2006) (only one among 28
units in the ECE area) - around 25 researchers (currently 10 PhD)
- based at the Polytechnic Institute of Porto
(ISEP/IPP) - Leading international research in
- Wireless Sensor Networks for time-critical
applications - COTS-based sensor networks communication
architecture (ART-WiSe) - innovative dominance-based MAC Protocols (WiDom,
WiseCan) - innovative data aggregation, interpolation and
in-network computing mechanisms - Real-Time Software Infrastructure
- QoS-aware Middleware
- collaborative Computing
- real-time languages and operating systems
- Scheduling and Schedulability Analysis
- probabilistic scheduling
- single, multicore and multiprocessor Scheduling
- communication scheduling (TDMA/SS)
- Real-time Factory Communications
- wired/wireless real-time fieldbus communications
today
3Buzzwords
- ubiquitous
- pervasive
- wireless
- mobile
- wearable
- M2M
- distributed
- embedded
- dynamic
- energy
The Internet of things is emerging
4Scale leads to limitations
- Embedded computing systems are scaling
- ?up
- in number of nodes (103106), and area (103
106 m2) - ? down
- in size (smart dust) and cost (lt1 /) per node
- which implies
- very low cost per node (for cost-effective
deployment) - no maintenance (at least for most of the nodes)
- long network/node lifetime (years)
- and stringent node resource limitations
- processing/memory speed, size
- communications radio coverage, bit rate
- energy battery size vs. capacity
5bringing important challenges
- resource limitations are big impairments to
- network/system lifetime
- energy-efficiency
- processing/transmitting huge amounts of
information - data fusion/aggregation, information processing,
network topologies, MAC and routing protocols - get tasks finished correctly and on time
- reliable and real-time computing
- get messages transmitted correctly and on time
- reliable and real-time communications
-
- and this is what we are addressing
6Which applications are we targeting?
- Monitoring/controlling time-critical
applications, such as - critical physical infrastructures (e.g. bridges,
tunnels) - homeland security
- utilities transportation systems (e.g.
electrical, gas, water, oil) - factory automation and process control in large
plants - domotics (home/building automation)
- park/forest hazard monitoring
- sports/religious/cultural events monitoring
- disaster management (e.g. searchrescue in
buildings/mines) - health care monitoring/management (e.g. in a
hospital) - intelligent transportation systems (e.g.
highways, trains, metro)
7ART-WiSe outlook
Architecture for Real-Time Communications in
Wireless Sensor Networks
- Objective
- real-time communications in large-scale
distributed embedded systems - Main Design Goals
- Real-Time
- Reliability
- Scalability
- Mobility
- Energy-efficiency
- Cost-effectiveness
- COTS standard technology
- Multiple Tiered Arch.
- Tier 2 backbone
- IEEE 802.11 (WiFi) or
- IEEE 802.16 (WiMAX) or
- Tier 1 sensor network
- IEEE 802.15.4/ZigBee
8ART-WiSe why IEEE 802.15.4/ZigBee?
- Energy-efficiency
- adaptable duty-cycles (100 ? 0)
- low data rates (20-250 kbps)
- low radio coverage (? 30 m)
- Traffic differentiation
- Real-Time traffic
- Guaranteed Time Slots (GTS)
- Best-effort traffic
- CSMA/CA mechanism
- Scalable network topologies
- star, mesh, cluster-tree
- up to 65000 nodes per PAN
- COTS standard technology
- many different manufacturers
- many different motes
9ART-WiSe results
- IEEE 802.15.4/ZigBee for WSNs
- New mechanisms/methodologies for
- engineering ZigBee cluster-tree WSNs
- energy/bandwidth tradeoff
- real-time and energy-efficient communications
- worst-case timing analysis/network dimensioning
- mitigating the hidden-terminal problem
- tolerating routers failure/link quality
degradation - traffic differentiation (high/low priority)
- respecting backward compatibility with standard
- Developed an open-source toolset
- network dimensioning MATLAB
- simulation models OPNET
- protocol stack nesC/TinyOS over MICAz and TelosB
motes
9
10WiDom outline
Prioritized Collision-Free MAC Protocol for
Wireless Sensor Networks
- Objective
- to provide upper bounds on communication delays
- also useful to perform efficient collaborative
distributed computing (wireless/wired sensor
networks and cyber-physical systems). - Outline
- Prioritized Medium Access Control (PrioMAC)
- grants medium access to the computer node with
the highest priority - originally created for wired networks, e.g
Controller Area Networks (CAN) - we apply this idea to the wireless domain WiDOM
Dominant Recessive
Node 3 is the only node that finishes the
arbitration without losing
11WiDom min/max example
example efficienty acquiring MIN/MAX of a
physical quantity in a region
MIN/MAX of sensor data in space can be obtained
with a time-complexity that is independent of the
number of sensor nodes
11
12WiDom interpolation example
example how to get information about a signal
(say concentration of a hazardous gas) that
varies quickly in time and space
Original Signal
Curve fitting
Interpolations of sensor data in space can be
obtained with a time-complexity that is
independent of the number of sensor nodes
12
13International recognition
- Our work on sensor networks has been recognized
at the highest level - best papers at top conferences ECRTS, RTSS, MASS
- collaboration in the TinyOS Net2 WG
- only non-US partner, with UBerkeley, USouth
California, UHarvard, UStanford, MIT - involvement in networks of research excellence
- ARTISTDesign and CONET NoEs
- 16 partners, e.g. SICS, ETH Zurich, TUDelft,
UCLondon, SAP, Schneider, Boeing, Telecom Italy - PT-CMU
- CISTER is the only Research Unit from the
Polytechnic - our publications are referenced by top level
research groups - UIUC, WU, UV, SSSUP, CMU,
- our web sites are quite visited and the open-ZB
toolset quite used - http//www.open-ZB.net over 44000 visits and
2300 downloads (in around 20 months) - visiting researchers/scholars from reputed
institutions - Prague, Pisa, Vienna, CMU (Raj Rajkumar, Peter
Steenkiste) - we are invited to take part in PCs of WSN events
- e.g. JRTS, RTSS, OPODIS DCOSS, ICDCS (WSN tracks)
13
14Some research collaborations with CMU
- Visits/meetings at
- CMU (Tovar, Pinho, Andersson, Pereira, Nogueira,
Alves) - Porto (Rajkumar, Steenkiste)
- WiDom-MBD
- Multiple Broadcast Domains (MBD)
- Radio add-on to CMU-Firefly
- for low-overhead implementation of WiDom
- Implementations in CMU-nano-RK
- WiDom (Firefly and MICAz)
- IEEE 802.15.4 (Firefly, MICAz and CISTER-TELEIA)
15facing RISK requires SKILLS and TOOLS ?
15
1616
17EXTRA SLIDES
17
18WiDom protocol animation
Prio001 (1)
Prio100 (4)
Prio010 (2)
Each node has a priority (of the message to
send) (here represented has a binary number).
19WiDom protocol animation
Someone transmitted a dominant bit. I Lost.
Tx Carrier
Tx Carrier
Prio001 (1)
Prio100 (4)
Prio010 (2)
Nodes transmit priority bit by bit. Nodes with
a dominant bit, transmit a carrier wave Nodes
with a recessive bit, listen.
20WiDom protocol animation
Someone transmitted a dominant bit. I Lost.
Tx Carrier
Prio001 (1)
Prio100 (4)
Prio010 (2)
Continue with the next bits
20
21WiDom protocol animation
Ended sending all bits and never heard a dominant
bit. I Won.
Prio001 (1)
Prio100 (4)
Prio010 (2)
Finally, only one node remains in the
tournament...
22WiDom protocol animation
Tx Message
Prio001 (1)
Prio100 (4)
Prio010 (2)
And transmits a message.