Conceptual table for EDCA default parameter values at a non-AP
QSTA. This table shall contain the four entries of the EDCA
parameters corresponding to four possible ACs (access category):
1) AC_BE (best effort, ACI=0)
2) AC_BK (background, ACI=1)
3) AC_VI (video, ACI=2)
4) AC_VO (voice, ACI=3)