Title: Loren Schwiebert
1What does the Future hold for Wireless Sensor
Networks?
- Loren Schwiebert
- Wayne State University
- Department of Computer Science
- loren_at_wayne.edu
- http//www.cs.wayne.edu/loren
2Why Wireless Sensors Now?
- Moores Law is making sufficient CPU performance
available with low power requirements in a small
size. - Research in Materials Science has resulted in
novel sensing materials for many Chemical,
Biological, and Physical sensing tasks. - Transceivers for wireless devices are becoming
smaller, less expensive, and less power hungry. - Power source improvements in batteries, as well
as passive power sources such as solar or
vibration energy, are expanding application
options.
3Current State of the Artin Wireless Sensors
4Typical Sensor Node Features
- A sensor node has
- Sensing Material
- Physical Magnetic, Light, Sound
- Chemical CO, Chemical Weapons
- Biological Bacteria, Viruses, Proteins
- Integrated Circuitry (VLSI)
- A-to-D converter from sensor to circuitry
- Packaging for environmental safety
- Power Supply
- Passive Solar, Vibration
- Active Battery power, RF Inductance
5Advances in Wireless Sensor Nodes
- Consider Multiple Generations of Berkeley Motes
6Historical Comparison
Consider a 40 Year Old Computer
7A Rosy Future for Wireless Sensors?
- Is the effort on wireless sensor protocols a
waste of time?? - Can we just wait 10-15 years until we have
sensors that are very powerful??
- NO!! Will still face
- Very limited storage
- Modest power supplies
8Proposed Applications of Wireless Sensors
9Smart Home / Smart Office
- Sensors controlling appliances and electrical
devices in the house. - Better lighting and heating in office buildings.
- The Pentagon building has used sensors
extensively.
10Biomedical / Medical
- Health Monitors
- Glucose
- Heart rate
- Cancer detection
- Chronic Diseases
- Artificial retina
- Cochlear implants
- Hospital Sensors
- Monitor vital signs
- Record anomalies
11Military
Remote deployment of sensors for tactical
monitoring of enemy troop movements.
12Industrial Commercial
- Numerous industrial and commercial applications
- Agricultural Crop Conditions
- Inventory Tracking
- In-Process Parts Tracking
- Automated Problem Reporting
- RFID Theft Deterrent and Customer Tracing
- Plant Equipment Maintenance Monitoring
13Traffic Management Monitoring
- Future cars could use wireless sensors to
- Handle Accidents
- Handle Thefts
- Sensors embedded in the roads to
- Monitor traffic flows
- Provide real-time route updates
14Driving Forces for AdoptingNew Technology
15Economic Factors
- New technologies replace existing technologies or
fill new niches when there are economic
advantages. - Wireless sensors will replace wired sensors
- No wiring lower costs
- More flexible deployments
- Wireless sensors will provide new services
- Provide cost advantages or lower overhead
- Improve product quality or product features
16Novelty
- Some early adopters use new technology simply for
novelty or the fun of it. Examples include - Java rings and internet watches.
- Maybe wireless sensors for dating or meeting new
people? - Personal wireless sensors for fun a temperature
monitor you carry around?
17Legal / Liability
- New technologies are adopted because of
government mandates - Air bags in automobiles
- Child safety seats
- Companies employ new technologies to avoid being
sued!! - Temperature sensors to detect coffee that is too
hot??
18 Entertainment
- New technology is adopted for entertainment.
- Playing games is major use of home PCs.
- So is Internet browsing.
- Games on cellular phones.
- 3D visualization for games.
- Games of tag using wireless sensors?
- Interactive role-playing games with sensors?
19Not Technical Superiority
- Useful technologies may not dominate the
marketplace for several reasons. - Delay in getting to market.
- Lack of standardization.
- Limited applications.
- Consumer preference VHS vs. Betamax.
- Weaker marketing or capitalization.
- Unusual that there are no alternative
technologies that can be used.
20Uses of New Technology
21Unexpected Killer Applications
- Useful applications often follow available
technology. For example, - PCs were available and people looked for a killer
app Visicalc. - The Internet was not created with these current
applications in mind - World Wide Web
- E-Commerce
- Peer-to-Peer Digital Music Sharing
22Unanticipated Uses Arise
- Once technology is available, creativity leads to
new applications - Sims Internet world
- E-Bay auctions
- Mirror for the Palm Pilot
- Digital cameras with PC interface
- What surprising applications for wireless sensor
networks? - Depends on sensor technology/form factor
23Some Technical Challenges
24Noisy Sensors
- Sensor readings can be inaccurate. Protocols
need to recognize this. - GPS Sensor
- Accurate within
- 2.8 meters
- Relative Humidity Sensor
- Accuracy of 5
- 8 at 90 Relative Humidity
- 2 with calibration
25Wireless Channel Conditions
- Limitations of wireless channels
- Noisy
- Interference
- Link Contention
- Unidirectional Links
- But inherently a broadcast medium
26Environmental Factors
- Wireless sensors need to operate in conditions
that are not encountered by typical computing
devices - Rain, sleet, snow, hail, etc.
- Wide temperature variations
- May require separating sensor from electronics
- High humidity
- Saline or other corrosive substances
- High wind speeds
27What will Wireless Sensor Networks Look Like in
the Near Future?
28Large-Scale Deployments
- Sensor networks will grow in size because of
- Lower cost
- Better protocols
- Advantages of dense networks
29Heterogeneous Sensors
- Homogeneous network of sensors has been the
typical assumption, but not the future!! - Combining sensors with different functions
- Hierarchy of sensors a few expensive powerful
sensors with more cheap sensors - Useful for special communication nodes
- A few sensor nodes with expensive sensors, such
as GPS-equipped sensors
30Mobile Sensors
- Sensors with Micromachines
- Low-Power Motors that Support Mobility
31General Purpose Sensors
- Single-purpose network is the typical assumption,
but not the future!! - Sensors for evolving applications
- Sensors that can adapt to changing objectives
- More memory and CPU will allow more complex
applications - Flexibility increases marketability
32Overlapping Coverage Areas
- Sensors will be deployed for specific
applications, but - These deployments will overlap physically
- Sensors will have different properties
- Users will want to combine these different
sensors for new applications - Temperature sensors for HVAC control
- Location tracking of employees
- Combine these for fire rescue operations
33Mixture of Wired and Wireless
- Wireless sensors will become a seamless part of
larger networks! - Combining wired sensors with wireless sensors
- Wired sensors can have more power
- Wired sensors can run TCP/IP
- Accessing wireless sensors through the Internet
- Need a gateway to translate requests
- Uploading/downloading information remotely
- Modifying wireless sensor tasks remotely
- Increased direct user interaction
34Some Impediments toCreating Future Applications
35Need a Standardized Interface
- Automated interaction between sensors implies
some standard mechanism for communication! - Requires compatible wireless technology
- Standardization a common theme
- TCP/IP for the Internet
- Java for Internet programming
- Jini, SLP, etc. for 802.11 wireless devices
- Need a service discovery protocol
- Enables standard interface among sensors above
the physical layer
36Service Discovery Protocol
Anyone need a printer?
"Dear Mom...I'm sitting..."
37Service Discovery Protocol (cont.)
- For a wireless sensor network, service discovery
provides - Automated calibration of new devices
- Highly dynamic system configurations
- Cooperation among resource poor devices
- Resource sharing device solutions
- Storage and long-range networking services can be
obtained from a nearby server - Less duplication of functionality
- Supports novel interactions in the future
38Security Issues
- Concerns about misuse and privacy
- Privacy issues may slow consumer adoption of
technology - User tracking RFID concerns
- Has not proved true on the Internet!
- Authentication and privacy are not always
complementary objectives - Do not want your medical sensor hacked!!
- Data tampering and computer viruses could be a
nightmare!
39Liability and Safety Concerns
- Companies may adopt wireless sensors to reduce
liability, but wireless sensors could also
increase liability - Use in critical applications could be limited
- Imagine a medical sensor fails!!
- Or an automotive theft deterrent system failure
- Companies will be slow to adopt technology that
increases their legal exposure - May delay adoption
40Software Engineering
- Imagine a heterogeneous wireless sensor network
with complex tasks and high levels of
interaction - End-user level products easy to use
- Software design??
- Debugging??
- Remote software updates??
- Example Send a request over the Internet to turn
on lights when your car reaches home. The
request fails.
41Summary and Conclusions
- Wireless sensor networks have a bright future
- Many applications have been proposed
- Potential to revolutionize human-computer
interactions - Availability of sensors will lead to new and
exciting applications - A lot of research remains to be done
- Wireless sensors will not evolve into traditional
computers - Many obstacles to overcome
- Allow realism to guide research efforts
42Acknowledgments
- THANK YOU
- Research collaborators (and for slides)
- Professor Gregory Auner
- Professor Sandeep K. S. Gupta
- Professor Golden G. Richard III
- Manish Kochhal
- Technical Assistance Joel Schwiebert