yeah zigbee is the other name for the IEEE 802.15.4 protocol. Whereas Xbee is a system/device, manufactured by Digi international that implements the zigbee protocol on its hardware.
BEAMer
Not really, ZigBee is addition layers of protocol that uses the 802.15.4 Mac and physical layers.
Digi Int has Xbee's that run 802.15.4 and ZigBee but they will not communicate with each other. There are also a few other protocols that Digi Int has for XBee modules such as DigiMesh.
The protocol is determined by the firmware loaded into a module and the chip set used in the module (series 1 or 2).
Which protocol to use is determined by what you need. For simple point to point (robot to/from PC) the 802.15.4 works well. If you have several robots that need to 'talk' to each other as well as a PC then the ZigBee protocol or DigiMesh may be better.
Digi Int has lots of documents and a good forum on their web site. Just beware that all the information is there but is written for professionals that understand more than just the basics of radio networking. That is one reason there is much confusion as to what an Xbee is and can do.
Once the protocol is understood, Xbee modules are great 'easy' to use bi-directional RF links. My next bot will be using an Xbee.
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