Introduction to Wireless Sensor Networks

What are sensor networks?

Sensor networks consist of many - up to several thousand - small distributed computing devices that sense and interact with the environment. Various sensors allow a sensor node to measure
temperature, sound, vibration, pressure, motion or pollution. Their low price and low energy
ensures that sensor networks can be deployed in large numbers. A sensor node consists of a smal
microcontroller, a radio device, some sensors, and a power supply, usually a battery. Their resources in terms of energy, memory, computational power and bandwidth are severely limited, making sensor nodes an interesting research topic. Due to their processing and communication abilities sensor networks are intelligent. Thus, the network can independently from human interaction deal with node failure, aggregate measurements from various nodes into meaningful data, reprogram selected nodes for new tasks

Why are sensor networks cool?

In the 1980s, the PC revolution put computing at our fingertips.
In the 1990s, the Internet revolution connected us to an information web that spans the planet.
And now the next revolution is connecting the Internet back to the physical world we live in-in
effect, giving that world its first electronic nervous system.
Call it the Sensor Revolution: an outpouring of devices that monitor our surroundings in ways we
could barely imagine a few years ago. Some of it is already here. The rest is coming soon

What are the real time applications?

WSN applications can be classified into two categories. monitoring and tracking. Monitoring applications include indoor/outdoor environmental monitoring, health and wellness monitoring, power monitoring, inventory location monitoring, factory and process automation, and seismic and structural monitoring. Tracking applications include tracking objects, animals, humans, and vehicles.



Road tunnel fire rescue with wireless sensor networks ( from Discovery)



There is more to go. Currently it's hardly 8-10 year old technology. The researchers are facing challenges in
  • Limited power
  • Ad-Hoc operation ( there is no centralized control over network )
  • Diversity in applications
  • Limited radio communication and computation capabilities
Quick Links and References

Crossbow blog for interesting applications currently deployed
National Science Foundation :WSN Page
Wireless sensor network survey : Jennifer Yick, Biswanath Mukherjee, Dipak Ghosal(Article in press) ScienceDirect 2008

9 comments:

Nirav said...

hi i read ur scrap in WSN community... and i would like to know regarding security issues in WSN. i would like to do some work in this area...

Gireesh said...

Sure Nirav
I am also reading mostly on security issues.
ping me in orkut, i will help with what ever i know

ujwala said...

Hi, The intro was nice. I m planning 2 work on QoS in WSN . Any guidance in that?

Gireesh said...

@ujwala
QoS , well in resource constrained network like WSN is really challenging
As far as i read, interesting thing is, guarenteed packet delivery , security and traffic generated as parameters to QoS

there are survey papers and recent articles, in case u want more details.

ujwala said...

can I have some link 2 paps on guaranteed packet delivery and security

Gireesh said...

well, depends on ur accebility to those papers
if u have access to IEEE/ACM/ScienceDirect,search for the same; survey papers are there in those archives.

Else send me a blank mail, I will reply with papers downloaded

Anonymous said...

Gud ...awsome...!

Spirited Youth said...

I wanted to simulate the localization in sensor networks., could ya guide me by the software to use ?

Gireesh said...

@above
if you want to emulate a tinyos program, you may try Avrora
Otherwise, try Omnet++ ( Castalia ) or NS2 patches