– 9 –
Master
Slave
System ID
confirmed
System ID
confirmed
A-Frame
A-Frame
V-Frame
V-Frame
V-Frame
V-Frame
5. Link Establishment
Accoding to the following Fig. 3-1, the requested side for link
establishment is the master.
The system have to exchange the A-Frame for link establishment,
and each system ID should be the same ID, and then the system
link is established.
The protocol and timing chart of link establishment are as fol-
lows.
Fig. 3-3. Link Establishment protocol
Master TX
Master RX
Slave RX
Slave TX
Master
Time Slot
Trip Delay
TX
RX
TX
RX
TX
A
V
A'
V
V
V
V
A
V
A'
V
Fig. 3-4. Link Establishment Timing Chart
6. State Change/Tarmination
After the RF link between HS and BS was established, a move-
ment of each state (State: ON-Hook, OFF-Hook, PAGE, InterCom,
etc) is sent through supervisory bits.
7. Error Recovery
In case of the following situation, The system becomes “Error
Recovery Mode”.
(1) The system failed to move to “Heart-Beat” during “Stand-by
mode, or failed “link establishment”.
(2) The system failed to keep the link.
