Medium Access Control (MAC) and Physical Layer (PHY) - CISE

4-June-07 P1901_PRO_016_r0
The HE send a CSMA frame ended with a CSMA token, and a priorized contention period is open for all the
nodes that can heard this token:
S
O
T
CSMA Token
CSMA PPDU
IPPDU1
P0min
P0max P1min
Backoff
slot time
Backoff time
CONTENTION WINDOW
P1max P2min
P2max P3min
Submission page 86 UPA-OPERA
S
O
T
Figure 25: CSMA Frame
PPDU
Contention winner Node
Each of the nodes will contend putting an SOT in a random position inside a predetermined range of the contention
window. The range is determined by the state of the node and the service class of the traffic that want to transmit
among other, as explained in section 6. The node that was able to send the SOT before any one, will win the right to
transmit a frame.
4.2 MAC STATES MANAGEMENT
MAC states include node states which are specific states managed both on the master side and the slave side.
They correspond to specific actions described here below.
4.2.1 Master side
From a master standpoint, a slave can be in three different states: Active, Idle, and Unregistered. These states
are related to the following master-side actions (see Figure 26 and Figure 27 ):
� Active: A master shall regularly transmit a data token to Active slaves. If a slave returns a data token
without using any of the time resources originally granted, the master may list this slave as Idle. The
master may also list the slave as Idle, if the only data sent has priority 7 (reserved for control packets).
P3max
Token