UniPro protocol stack: Difference between revisions

Content deleted Content added
VdHamer (talk | contribs)
m L2 data frames: some -> two or more
VdHamer (talk | contribs)
m L2 control frames: The other -> the other type (etc)
Line 166:
 
In addition to data frames which contain user data, L2 also transmits and receives control frames. The control frames can be distinguished from data frames by three bits in the first symbol. There are two types of control frames:
* One type ("AFC", 3 symbols) serves to acknowledge successfully received data frames.
* The other type ("NAC", 2 symbols) notifies the corresponding transmitter that an incorrect frame has been received.
Note that these L2 types of control frames are sent autonomously by L2, without any control by higher layers.
 
{| border="1" cellpadding="3" style="margin: 1em auto 1em auto"