MT8910-1
•
TL:
A 10 kHz activation tone sourced by the
LT which is generated by sending a
continuous pattern of four +3 symbols
followed by four -3 symbols.
SL0 is a no signal condition generated
from the LT.
An LT generated signal consisting of a
framed (but not superframed),
scrambled 2B1Q signal which carries all
1s in the B-, D- and M-channels. This
signal is used to train the LT’s echo
canceller.
•
SL2:
Preliminary Information
An LT generated signal consisting of a
fully framed and superframed
scrambled 2B1Q signal which carries all
0s in the B- and D-channels with
information in the M-channel. This
signal is used to train the NT’s DFE.
An LT generated signal consisting of a
fully framed and superframed scrambled
2B1Q signal which carries information in
all the B-, D- and M-channels.
•
•
SL0:
SL1:
•
SL3:
MRST Pin
ST.Tx = Start Timer x
STP.Tx = Stop Timer x
LAR = Local Activation Request
LDR = Local Deactivation Request
SFS = Superframe Synchronization Acquired
Full Reset
(Power down
Tx-SNO
RCV TL or
LAR
ST.T0
Alerting
Tx-TN (9 ms)
RCV TL
ST.T0
STP.T2
Expiry of T2
RCV Reset
Tx-SN0
Loss of signal
STP.T3
ST.T2
EC Training
Tx-SN1
EC
Converged
ST.T1
Quiet
Tx-SN0
Signal
Detected
STP.T1
Train
DFE/Timing
Tx-SN0
SL2
Detected
Framing
Tx-SN2
SFS
T0 = 15 sec timer
T1 = 480 ms timer
T2 = 40 ms timer
T3 = 520 ms timer
Note
1
:
Loss of received signal will
result in a loss of sync.
Expiry of T0
Expiry of T1
Expiry of T0
Expiry of T0
Loss of
far-end
signal
STP.T3
ST.T2
Expiry
of T3
ST.T3
ST.T3
Active
Tx-SN3
LDR
ST.T3
Pending Deact.
Tx-SN3
Loss of BFS > 480ms
1
ST.T3
Tear Down
Tx-SN0
Figure 6b - Activation/Deactivation State Diagram - NT Mode
9-10