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

4-June-07 P1901_PRO_016_r0
� Idle: No data token is transmitted to an Idle slave, that is to say this slave does not get any scheduled
transmission opportunity until it is required. This feature reduces the transmission of empty frames by non
active slaves and it also increases the network performance, since the transmission opportunities not given
to Idle slaves can be used by other Active users. A master shall regularly transmit Polling Frames to an Idle
slave. This management is done in a different way and with different token depending on the type of the
slaves: TDRs or CPEs.
o When the Idle slave is a CPE, the master shall poll it to check if it has data to transmit from a
service class different from number 7 (See 8). If yes, it must be considered Active again. If
answer is no, it shall be considered registered, although it has no data of higher service class to
transmit. When the CPE has no activity, that means, no data is transmitted during long times,
must be considered as Unregistered. This information is obtained by means of two different
types of Polling Tokens: Active Polling Tokens and Alive Polling Tokens respectively. Up to
32 CPEs can be polled with only one of these Polling Frames.
� Active Polling Tokens shall be regularly transmitted by the master to manage
transitions from Idle to Active. A slave which replies to an Active Polling Token shall
be listed as Active by its master. A master is constrained to transmit an Active Polling
Token with a maximum interval equal to MAX_ACTIVE_POLL_INTERVAL.
� Alive Polling Tokens shall be regularly transmitted by the master to manage transitions
from Idle to Unregistered. A master is constrained to transmit an Alive Polling Token
with a maximum interval equal to MAX_ALIVE_POLL_INTERVAL. A slave which
does not reply to a number of Alive polling tokens equal to MAX_ALIVE_TOKENS
shall be listed as Unregistered.
o When the slave is a TDR, the master shall only consider it as Idle when neither it nor any of the
slaves in its BPL sub-tree are transmitting or receiving data of service class 1 to 6; this
information is available in the field Frame Priority sent in the Data Token (see 0). The
management of idle TDRs from the master side is slightly different from idle CPEs, although
the concept stays the same. The reason for these differences is that TDRs shall provide some
periodic services to the users in their BPL sub-tree and to other non-registered users within
their visibility area apart from notifying if they have traffic to send. The master shall send a
TDR Polling Frame to every Idle TDR connected to it as a slave, with a maximum interval
equal to MAX_ACTIVE_POLL_INTERVAL.
The master shall give enough validity in this polling token for the TDR to send at least an
Access Frame every MAC_ACCESS_INTERVAL, as many Polling Frames to CPEs as
required (from 0 to 4, depending on the number of banks needed) every
MAX_ACTIVE_POLL_INTERVAL and as many TDR Polling Frames as TDRs connected to
it as slaves every MAX_ACTIVE_POLL_INTERVAL. The validity should be calculated from
the topology information provided by the Cluster Discovery Protocol (see 0).
A TDR that does not reply a number of consecutive TDR Polling Tokens equal to
MAX_ALIVE_TOKENS shall be listed as Unregistered.
Submission page 87 UPA-OPERA