DASH7, ZIGBEE, BLUETOOTH, XBEE SUPPORT FULL DUPLEX COMMUNICATION?

I want to do my main project in my university in this domain. Please help me out.

you can get full duplex using multiple channels, not sure about simultaneous full duplex on the zigbee devices but certainly their big brothers that work on 900mhz. (also unlicensed)

I didnt get what their "big brothers" are. Are they the newer versions of Zigbee? Can i get sufficient information on them? Thanks in advance.

http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/point-multipoint-rfmodules/ thats the family made by digi

Whether a radio link is full or half duplex has more to do with the radio implementation than with the protocol that runs over the link. In general, a channel of radio is half-duplex; the radio can either transmit or receive. If you want true full duplex, you need two radios running on different frequencies/channels. Now, if your link is fast enough (about twice the bandwidth needed for your application, even counting startup delays and preambles and whatnot), you may be able to make it LOOK like a full-duplex connection. I'm pretty sure you could do a reasonable job of bi-directional voice communications over an old 10Mbps half-duplex ethernet, for example.

In general, the questions you are asking WRT your project indicate a poor understanding of radio in general (because you're asking the wrong questions), and you're going to need to clear some of that up before you can start thinking about the higher level details (bluetooth vs zigbee vs dash7, etc.) I don't blame you; it's essentially one of those areas that you are led to believe that you can ignore by buying a pre-made module. But you can't, really.

(Hmm. Is a bluetooth headset actually full-duplex?)

okay, i will soon get acquainted with the basics of radio transmission.

I think bluetooth headset is full duplex. And what i think is by replacing the bluetooth with the latest(xbee/zigbee) technology, why can't we achieve full duplex voice communication with some betterment than the existing?

Thanks.

Bluetooth appears to do the "high bandwidth looks like full duplex even though it only goes one direction at a time" thing.

http://www.bluetooth.com/English/Technology/Works/Pages/Overview_of_Operation.aspx

I'm not clear on the differences between zigbee and bluetooth (they have a lot of similarities), but BT was designed to support things like headsets ("full duplex")

A2DP is stereo Bluetooth, so there is enough bandwidth for two channels, why couldnt it work?