How do Wireless Sensors Communicate?

[encima]

Hi All,

Please excuse the genericity of this question, I know they can communicate via Zigbee, WiFi, 3G etc. My question is how, exactly, do they communicate? 

I have read (a lot) of literature on Wireless Sensor Networks and no-one seems to have gone down to the basics of how they communication?

For example, if a sensor network communicates using WiFi, how is this done, as they can only handle one connection at a time. I have assumed how they communicate, and implemented this, but I thought I would ask the people dealing with the hardware and software how it is done?

Apologies if this seems like a stupid question, I am a first year PhD student so I am still new to this!

Thanks in advance!

[Liam_A]

Hi there!

Thanks for your post, definitely a valid question!

I'm not sure as to hpw much you have read up on this, but some information I found quite useful regarding this subject can be found in the following links. Please take a look and let us know how you get on.

This wireless selection guide contains some useful network information:

http://zone.ni.com/devzone/cda/tut/p/id/10700

Regarding WiFi specifically, this link should be of some use:

http://zone.ni.com/devzone/cda/tut/p/id/8630

For other sensor networks issues, the following link should contain some useful information for you.

http://www.ni.com/wsn/

Links off these pages should also contain more specific information as you dig deeper.

I hope this helps!

[encima]

Hi, Thanks for getting back to me.

All useful links! Most of them seem to point to Single hop links, where the sensors are linked to a gateway. 

Do you know how they work if they are multi hop, as this must be quite different?

Thanks!

[seaelite]

You also may want to check into this wiki:   http://en.wikipedia.org/wiki/Sensor_web  There are some links to more reading that describe a different form of wireless communication w/out the use of hubs/routers/gateways, etc.