xbee shield: the use of the "associate" led

Hi guys! i've just bought the xbee shield with 2 xbee pro. on the shield there's a "associate" led, but i cannot understand it's use, since it blinks with the same frequency either when the communication is established (the arduino sends a stream to the other one) or not (one of them is powered off). Could anyone explain me it's use? thanks a lot! ;)

It's the only indication you have that the xbee is powered up and functioning. It does not tell you whether it is communicating with any other XBee(s).

look at this:

http://www.humboldt.edu/~cm19/XBee%20setup.pdf (step 7)