I am working on the CCA mechanism in 802.11 network. From STD, I found the
For DSSS (Specified in Sec 220.127.116.11):
The DSSS PHY shall provide the capability to perform CCA according to at
least one of the following three methods:
— CCA Mode 1: Energy above threshold. CCA shall report a busy medium upon
detection of any energy above the ED threshold.
— CCA Mode 2: Carrier sense only. CCA shall report a busy medium only upon
detection of a DSSS signal, even if the signal is below the ED threshold.
— CCA Mode 3: Carrier sense with energy above threshold. CCA shall report a
busy medium upon detection of a DSSS signal with energy above the ED
My questions are as follows:
1) Which mode is MADWiFi driver using?
2) Does the antenna keeping carrier sesing the channel continuously or it
only senses at the beginning of each timeslot? It is well known if the
channel is sensed idle, one node can reduce its countdown value by one;
3) Would someone can give me some hints on where is the corresponding part
of carrier sensing and DCF in MADWifi driver?
Thanks in advance.
Get latest updates about Open Source Projects, Conferences and News.