.rs
.\" Troff code generated by TPS Convert from ITU Original Files
.\"                 Not Copyright ( c) 1991 
.\"
.\" Assumes tbl, eqn, MS macros, and lots of luck.
.TA 1c 2c 3c 4c 5c 6c 7c 8c
.ds CH
.ds CF
.EQ
delim @@
.EN
.nr LL 40.5P
.nr ll 40.5P
.nr HM 3P
.nr FM 6P
.nr PO 4P
.nr PD 9p
.po 4P

.rs
\v | 5i'
.ce 1000
APPENDIX\ IV
.ce 0
.ce 1000
(to Recommendation G.961)
.sp 9p
.RT
.ce 0
.ce 1000
\fBElectrical characteristics of an AMI transmission system\fR 
.sp 1P
.RT
.ce 0
.ce 1000
\fBusing a TCM method\fR 
.ce 0
.LP
IV.1
	\fILine code\fR 
.sp 1P
.RT
.PP
For both directions of the transmission, the line code is AMI.
The coding scheme will be performed in such a way that a binary ZERO is
represented by no line signal, while a binary ONE is represented by a positive 
or negative pulse alternately. 
.RT
.sp 1P
.LP
IV.2
	\fISymbol rate\fR 
.sp 9p
.RT
.PP
The symbol rate is determined by the line code, rate of the
information stream and the frame structure. The bit symbol rate is
320\ kbauds.
.RT
.sp 2P
.LP
IV.2.1\ \ \fIClock requirements\fR 
.sp 1P
.RT
.sp 1P
.LP
IV.2.1.1\ \ \fINT1 free running clock accuracy\fR 
.sp 9p
.RT
.PP
The accuracy of the free running clock in the NT1 shall be
\(+- | 0\ ppm.
.RT
.sp 1P
.LP
IV.2.1.2\ \ \fINT1 clock tolerance\fR 
.sp 9p
.RT
.PP
The NT1 shall accept a clock accuracy from the LT of \(+- | 0\ ppm.
.RT
.sp 1P
.LP
IV.2.1.3\ \ \fILT clock tolerance\fR 
.sp 9p
.RT
.PP
The LT shall accept a clock accuracy from the ET of \(+- | 0\ ppm.
.RT
.sp 1P
.LP
IV.3
	\fIFrame structure\fR 
.sp 9p
.RT
.PP
The frame structure contains a frame word, N times (2B\ +\ D) and a CL 
channel. 
.RT
.ce
\fBH.T. [T24.961]\fR 
.T&
lw(60p) | lw(30p) | lw(60p) | lw(12p) | lw(30p) .
				
.T&
cw(60p) | cw(30p) | cw(60p) | cw(12p) | cw(30p) .
Frame word	CL channel	\fIN\fR  | times (2B + D)	P	Space
.TE
.IP P
Parity bit: The P bit is used to get an even number of binary ONEs in
a frame; so it is set to binary ONE or binary ZERO when the number of
binary ONEs in a frame is odd or even respectively
.nr PS 9
.RT
.ad r
\fBTable, [T24.961], p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
IV.3.1\ \ \fIFrame length\fR 
.sp 9p
.RT
.PP
The number \fIN\fR of (2B\ +\ D) slots in one frame is twenty.
.RT
.sp 1P
.LP
IV.3.2\ \ \fIBit allocation in direction LT\(hyNT1\fR 
.sp 9p
.RT
.PP
In Figure IV\(hy1/G.961, the bit allocation is given.
.RT
.sp 1P
.LP
IV.3.3\ \ \fIBit allocation in direction NT1\(hyLT\fR 
.sp 9p
.RT
.PP
In Figure IV\(hy2/G.961, the bit allocation is given.
.bp
.RT
.LP
.rs
.sp 47P
.ad r
\fBFigure IV\(hy1/G.961 ITALIENNE [T25.961] \ \ 
(\*`a traiter comme tableau MEP),   p.2\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 47P
.ad r
\fBFigure IV\(hy2/G.961 ITALIENNE [T26.961] \ \ 
(\*`a traiter comme tableau MEP),   p.3\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 1P
.LP
IV.4
	\fIFrame word\fR 
.sp 9p
.RT
.PP
The frame word is used to allocate bit position to the 2B\ +\ D\ +\ CL 
channels. It may, however, also be used for other functions. 
.RT
.sp 1P
.LP
IV.4.1\ \ \fIFrame word in direction LT\(hyNT1\fR 
.sp 9p
.RT
.PP
The code for the frame word will be \*Q100000M0\*U; M is \*Q1\*U/\*Q0\*U
alternating bit in every frame.
.RT
.sp 1P
.LP
IV.4.2\ \ \fIFrame word in direction NT1\(hyLT\fR 
.sp 9p
.RT
.PP
The code for the frame word will be \*Q1000000M\*U; M is \*Q1\*U/\*Q0\*U
alternating bit in every frame.
.RT
.sp 1P
.LP
IV.5
	\fIFrame alignment procedure\fR 
.sp 9p
.RT
.PP
The frame alignment procedure is defined as follows.
.RT
.LP
	a)
	\fIFrame alignment state\fR 
.LP
	The transmission system is considered to be frame alignment
state if the frame word has been identified in the same position
for three consecutive frames.
.LP
	b)
	\fILoss of frame alignment state\fR 
.LP
	The transmission system is considered to be loss of frame
alignment state if the frame word has not been identified in the
expected frame position for six frames before identifying the
frame word in the frame position for twelve frames.
.sp 1P
.LP
IV.6
	\fIMultiframe\fR 
.sp 9p
.RT
.PP
To enable bit allocation of the CL channel in more frames next to each 
other, a multiframe structure may be used. The start of the multiframe 
is determined by the frame word. The total number of frames in a multiframe 
is 
four.
.RT
.sp 1P
.LP
IV.6.1\ \ \fIMultiframe word in direction LT\(hyNT1\fR 
.sp 9p
.RT
.PP
The multiframe is identified by the multiframe bit allocated in the CL 
channel. The code for the multiframe word, which is defined by the 
multiframe bits in four consecutive frames under the frame alignment state, 
is \*Q1000\*U. 
.RT
.sp 1P
.LP
IV.6.2\ \ \fIMultiframe word in direction NT1\(hyLT\fR 
.sp 9p
.RT
.PP
The same as IV.6.1.
.RT
.sp 1P
.LP
IV.7
	\fIFrame offset between LT\(hyNT1 and NT1\(hyLT frames\fR 
.sp 9p
.RT
.PP
The NT1 shall synchronize its frame on the frame received in the
direction LT to NT1 and will transmit its frame with an offset. Relative 
frame position at the NT1 input/output is as follows. The first bit of 
each frame 
transmitted from the NT1 toward the LT shall be delayed by\ 383 up to 384\ bit
periods with respect to the first bit of the frame received from the LT.
.RT
.sp 2P
.LP
IV.8
	\fICL channel\fR 
.sp 1P
.RT
.sp 1P
.LP
IV.8.1\ \ \fIBit rate\fR 
.sp 9p
.RT
.PP
The bit rate for the CL channel is 3.2 kbit/s.
.RT
.sp 1P
.LP
IV.8.2\ \ \fIStructure\fR \v'3p'
.sp 9p
.RT
.LP
	a)
	Thirty two bits (3.2 kbit/s) are allocated in a multiframe
for the use of CL channel.
.LP
	b)
	Four bits (0.4 kbit/s) are allocated to multiframe bits.
.LP
	c)
	Sixteen bits (1.6 kbit/s) are allocated to maintenance and
operational control functions in direction LT to NT1, and to
maintenance and operational information functions in direction
NT1 to LT.
.LP
	d)
	Twelve bits (1.2 kbit/s) are allocated to a cyclic
redundancy check (CRC) function.
.bp
.sp 1P
.LP
IV.8.3\ \ \fIProtocols and procedures\fR 
.sp 9p
.RT
.PP
Protocols and procedures of maintenance/operational
control/information are as follows.
.RT
.LP
	a)
	Transfer modes are bit\(hyoriented.
.LP
	b)
	Sending modes are continuous.
.LP
	c)
	Identification is confirmed by identical bits receiving for
three consecutive multiframes under the frame alignment state.
.LP
	d)
	Duration of control invocations is as long as sending
control is identified.
.LP
	e)
	Duration of information invocations is as long as causing
event is identified.
.sp 1P
.LP
IV.9
	\fIScrambling\fR 
.sp 9p
.RT
.PP
Scrambling will be applied on 2B\ +\ D channels and the scrambling
algorithm shall be as follows.
.RT
.LP
	\(em
	In direction LT\(hyNT1:\ \fIx\fR \u9\d
\s11\(ci
\s6+
.PS 10
\fIx\fR \u5\d
\s11\(ci
\s6+
.PS 10
1
.RT
.LP
	\(em
	In direction NT1\(hyLT:\ \fIx\fR \u9\d
\s11\(ci
\s6+
.PS 10
\fIx\fR \u5\d
\s11\(ci
\s6+
.PS 10
1
.RT
.sp 1P
.LP
IV.10\ \ 
\fIActivation/deactivation\fR 
.sp 9p
.RT
.PP
Activation/deactivation is defined in Recommendation G.960, \(sc\ 5.
Applications provided by the transmission system are described as follows.
.RT
.sp 1P
.LP
IV.10.1\ \ \fISignals used for activation\fR 
.sp 9p
.RT
.PP
Definition of the signals used for activation/deactivation (SIGs) are listed 
below. Signals used for start\(hyup (bits in the CL channel are not 
available) and bits in the CL channel (in already established frames) are
defined.
.RT
.LP
	a)
	Signals used for start\(hyup (CL not available):
.LP
	\(em
	SIG 0 (NT1 to LT and LT to NT1): No line signal.
.LP
	\(em
	SIG 1 (LT to NT1): A signal which deactivates the line
and the interface at T reference point.
.LP
	\(em
	SIG 2 (NT1 to LT): An awake signal to invoke the LT
layer 1 that it has to enter the power up state and
provide for the activation of the line and the interface
at T\ reference point. It is invoked by receiving the
signal INFO\ 1 across the T\ reference point in case of the
activation from the user side. This signal is also used as
awake acknowledgement on receiving of the signal SIG\ 3 in
case of the activation from the network side.
.LP
	\(em
	SIG 3 (LT to NT1): An awake signal to invoke the NT1
layer\ 1
that it has to enter the power up state and prepare for
synchronization on an incoming signal from the LT. This
signal is also used as awake acknowledgement on receiving
of the signal SIG\ 2 in case of the activation from the
user side.
.LP
	\(em
	SIG 4 (LT to NT1): A signal which contains framing
information and allows the synchronization of the receiver
in the NT1.
.LP
	\(em
	SIG 5 (NT1 to LT): A signal which contains framing
information and allows the synchronization of the receiver
in the LT. It informs the LT that the NT1 has synchronized
on the signal SIG\ 4.
.LP
	b)
	Bits in CL channel in already established frame:
.LP
	\(em
	SIG 6 (LT to NT1): A signal which requires the NT1 to
establish the full layer\ 1 information transfer capability
available between the NT1 and LT, and requires the NT1
to activate the T\ interface by sending the signal INFO\ 2
across the T\ reference point.
.LP
	\(em
	 SIG 7 (LT to NT1): A signal which requires the NT1 to establish the full 
layer\ 1 information transfer capability available between TE and the ET 
by sending the signal INFO\ 4 across the T\ reference point. 
.LP
	\(em
	 SIG 8 (NT1 to LT): A signal which indicates that the interface at T\ 
reference point is activated, and requires the LT to provide the full 
layer\ 1 information transfer capability available between TE and the ET. 
It is invoked by receiving of the signal INFO\ 3 across the T\ reference 
point. 
.LP
	\(em
	 SIG 9 (LT to NT1): A signal which requires the NT1 to establish the full 
layer\ 1 information transfer capability available between the NT1 and 
LT, and requires the NT1 to activate the loopback\ 2. 
.LP
	\(em
	SIG 10 (NT1 to LT): A signal which indicates that the
loopback\ 2 is activated in the NT1, and requires the LT to provide the full
layer\ 1 information transfer capability available between the NT1 and ET.
.LP
	\(em
	SIG 11 (LT to NT1 and NT1 to LT): A synchronization signal
which contains framing information and 2B\ +\ D\ +\ CL channels.
.bp
.LP
	\(em
	 SIG 12 (NT1 to LT): A signal which indicates that the receiver on the 
T\ interface side of the NT1 has entered lost framing state. 
.LP
	\(em
	 SIG 13 (LT to NT1): A signal which indicates that the receiver on the 
line side of the LT has entered lost framing state. This signal also 
contains a function as the signal SIG\ 4.
.LP
	\(em
	SIG 14 (NT1 to LT): A synchronization signal which contains
framing information and 2B\ +\ D+\ CL channels; bits in the 2B\ +\ D channels 
are 
set to be idle.
.LP
	\fINote\fR \ \(em\ Definition of the function element (FEs) across the
V\ reference point is described in Recommendation\ G.960, \(sc\ 5.4. FEs 
used for 
activation/deactivation are relisted in Table\ IV\(hy1/G.961.
.ce
\fBH.T. [T28.961]\fR 
.ce
TABLE\ IV\(hy1/G.961
.ce
\fBThe repertoire of function elements associated with the\fR 
.ce
\fBactivation/desactivation procedures\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(36p) | cw(36p) | cw(108p) .
FEs	Direction	Repertoire
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 1	ET to LT	 {
Activation request for the interface at T reference
point
 }
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 5	ET to LT	 {
Deactivation request for the line and the interface at T reference
point
 }
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 9	ET to LT	 {
Activation request for loopback 1
 }
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 8	ET to LT	 {
Activation request for loopback 2
 }
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 4	LT to ET	 {
The T interface is activated or a loopback is provided
respectively
 }
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 3	LT to ET	The line is activated
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 6	LT to ET	 {
The line and the interface at T reference point are
deactivated
 }
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 7	LT to ET	Error indication
_
.T&
cw(36p) | cw(36p) | lw(108p) .
FE 2	LT to ET	 {
Request to start timer T1 within the ET
layer\ 1
 }
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau IV\(hy1/G.961 [T28.961], p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
IV.10.2\ \ \fIDefinition of internal timers\fR 
.sp 9p
.RT
.PP
Timer T2 (see Recommendation\ I.430, \(sc\ 6) resides within the LT
layer\ 1.
.RT
.sp 1P
.LP
IV.10.3\ \ \fIDescription of the activation procedure\fR \v'3p'
.sp 9p
.RT
.LP
	a)
	Activation from the network side: See
Figure\ IV\(hy3/G.961.
.LP
	b)
	Activation from the user side: See Figure\ IV\(hy4/G.961.
.LP
	c)
	Deactivation from the network side: See Figure IV\(hy5/G.961.
.LP
	d)
	Activation of loopback 2: See Figure IV\(hy6/G.961.
.PP
\fINote\ 1\fR \ \(em\ Activating the line system only, where the full
information transfer capability is available while the interface at T\ 
reference point remains deactivated, is not provided. 
.PP
\fINote\ 2\fR \ \(em\ A non\(hytransparent loopback 1 is provided where no line
signal is transmitted at the LT 2\(hywire point.
.bp
.PP
\fINote\ 3\fR \ \(em\ A non\(hytransparent loopback 2 is provided where 
INFO\ 0 is 
sent from the NT1 at the interface at T\ reference point.
.PP
\fINote\ 4\fR \ \(em\ A repeater is not applicable.
.RT
.LP
.rs
.sp 23P
.ad r
\fBFigure IV\(hy3/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 23P
.ad r
\fBFigure IV\(hy4/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 16P
.ad r
\fBFigure IV\(hy5/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 21P
.ad r
\fBFigure IV\(hy6/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
IV.10.4\ \ \fIState transition table NT1\fR 
.sp 9p
.RT
.PP
State transition table NT1 as a function of INFOs and SIGs is
defined in Table\ IV\(hy2/G.961.
.RT
.sp 1P
.LP
IV.10.5\ \ \fIState transition table LT\fR 
.sp 9p
.RT
.PP
State transition table LT as a function of FEs, SIGs and the
internal timer T2 is defined in Table 
IV\(hy3/G.961.
.bp
.RT
.ce
\fBH.T. [T29.961]\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
TABLE\ IV\(hy2/G.961
.T&
cw(342p) .
 {
\fBState transition table NT1\fR
 }
.TE
.TS
center box ;
cw(18p) | cw(24p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) , ^  | ^  | c | c | c | c | c | c | c | c | c | c 
^  | ^  | c | c | c | c | c | c | c | c | c | c.
Event	State name  State code  Tx	Deactive	Pending power activation	 {
Pending activation of line at NT1 side
 }	 {
Pending activation of line at LT side
 }	Line active	T\(hy interface pre\(hyactive	T\(hy interface active	 {
Lost framing of T\(hy interface
 }	Ligne active	Loopback 2 active
		NT 1.0	NT 1.1	NT 1.2	NT 1.3	NT 1.4	NT 1.5	NT 1.6	NT 1.7	NT 2.1	NT 2.2	INFO 0	INFO 0	INFO 0	INFO 0	INFO 2	INFO 2	INFO 4	INFO 2	INFO 0	INFO 0	SIG 0	SIG 2	SIG 2	SIG 5	SIG 14	SIG 8	SIG 11	SIG 12	SIG 14	SIG 10  SIG 11
_
.T&
cw(42p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
SIG 1	/	NT 1.0	NT 1.0	NT 1.0	NT 1.0	NT 1.0	NT 1.0	NT 1.0	NT 1.0	NT 1.0
_
SIG 3	NT 1.2	NT 1.2	\(em	\(em	/	/	/	/	/	/
_
Line of NT1 side active	/	/	NT 1.3	\(em	\(em	\(em	\(em	\(em	\(em	\(em
_
SIG 6	/	/	/	NT 1.4	\(em	\(em	\(em	\(em	\(em	\(em
_
SIG 7	/	/	/	/	/	NT 1.6	\(em	\(em	/	/
_
SIG 9	/	/	/	NT 2.1	/	/	/	/	\(em	\(em
_
.T&
cw(42p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
SIG 13	/	/	/	\(em	NT 1.3	NT 1.3	NT 1.3	NT 1.3	NT 1.3	NT 1.3
_
.T&
cw(42p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
Lost framing of T interface	/	/	/	/	/	NT 1.7	NT 1.7	\(em	/	/
_
.T&
cw(42p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
 {
Lost framing of line at NT1 side
 }	/	/	/	NT 1.2	NT 1.2	NT 1.2	NT 1.2	NT 1.2	NT 1.2	NT 1.2
_
.T&
cw(42p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
Receiving INFO 1	NT 1.1	\(em	\(em	\(em	\(em	/	/	/	\(em	\(em
_
.T&
cw(42p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
Receving INFO 3	/	/	/	/	NT 1.5	\(em	\(em	NT 1.5	/	/
_
.T&
cw(42p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
Loopback 2 established	/	/	/	/	/	/	/	/	NT 2.2	\(em
.TE
.LP
/
Impossible event
.LP
\(em
No state change
.nr PS 9
.RT
.ad r
\fBTableau IV\(hy2/G.961 ITALIENNE [T29.961], p.9\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [T30.961]\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
TABLE\ IV\(hy3/G.961
.T&
cw(342p) .
 {
\fBState transition table LT\fR
 }
.TE
.TS
center box;
cw(18p) | cw(30p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) , ^  | ^  | c | c | c | c | c | c | c | c | c 
^  | ^  | c | c | c | c | c | c | c | c | c.
Event	State name  State code  Tx	Deactive	Pending activation of line	Line active	T\(hy interface active	Pending deactivation	Lost framing of line	Pending activation of line	Line active	Loopback 2 active
		LT 1.0	LT 1.1	LT 1.2	LT 1.3	LT 1.4	LT 1.5	LT 2.1	LT 2.2	LT 2.3	SIG 0	SIG 3  SIG 4	SIG 6	SIG \ 7  SIG 11	SIG 1	SIG 13	SIG 3  SIG 4	SIG 9	SIG 11
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
SIG 2	FE 2  LT 1.1	\(em	\(em	/	/	\(em	\(em	/	/
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
Line fully  active	/	FE 3  LT 1.2	\(em	\(em	\(em	FE 3  LT 1.2	FE 3  LT 2.2	\(em	\(em
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
SIG 8	/	/	FE 4  LT 1.3	\(em	\(em	/	/	/	/
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
SIG 10	/	/	/	/	/	/	/	FE 4  LT 2.3	\(em
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
Lost framing  of line	/	/	FE 7  LT 1.5	FE 7  LT 1.5	\(em	\(em	/	FE 7  LT 2.1	FE 7  LT 2.1
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
SIG 12	/	/	/	FE 7  LT 1.2	\(em	/	/	/	/
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
Expiry of  timer T2	/	/	/	/	LT 1.0	/	/	/	/
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
FE 1	LT 1.1	/	/	/	/	/	/	/	/
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
FE 5	/	ST.T2  LT 1.4	ST.T2  LT 1.4	ST.T2  LT 1.4	/	ST.T2  LT 1.4	ST.T2  LT 1.4	ST.T2  LT 1.4	ST.T2  LT 1.4
_
.T&
cw(48p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) | cw(36p) | cw(30p) .
FE 8	2.1	/	/	/	/	/	/	/	/
.TE
.LP
/
Impossible event
.LP
\(em
No state change
.nr PS 9
.RT
.ad r
\fBTableau IV\(hy3/G.961 ITALIENNE [T30.961], p.10\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 1P
.LP
IV.10.6\ \ \fIActivation times\fR 
.sp 9p
.RT
.PP
See Recommendation G.960, \(sc\(sc\ 5.5.1 and\ 5.5.2.
.RT
.sp 1P
.LP
IV.11\ \ \fIJitter\fR 
.sp 9p
.RT
.PP
Jitter tolerance is intended to ensure that the limits of
Recommendation\ I.430 are supported by the jitter limits of the transmission
system on local lines. The jitter limits given below must be satisfied
regardless of the length of the local line and the inclusion of one
regenerator, provided that they are covered by the transmission media
characteristics (see \(sc\ 3). The limits must be met regardless of bit 
patterns in the\ B, D and\ CL channels. 
.RT
.sp 1P
.LP
IV.11.1\ \ \fINT1 input signal jitter tolerance\fR 
.sp 9p
.RT
.PP
\fB
The NT1 shall meet the performance objective with wander/jitter at the 
maximum magnitudes indicated in Figure\ IV\(hy7/G.961, for single jitter 
frequencies in the range of 3\ Hz to 80\ kHz, superimposed on the test signal
source. The NT1 shall also meet the performance objectives with wander 
per day of up to 0.1\ UI peak\(hyto\(hypeak where the maximum rate of change 
of phase is 
1.0\ UI/hour.
.RT
.LP
.rs
.sp 32P
.ad r
\fBFigure IV\(hy7/G.961 [T27.961] \ \ 
(\*`a traiter comme tableau MEP), p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
IV.11.2\ \ \fINT1 output jitter limitations\fR 
.sp 9p
.RT
.PP
With the wander/jitter as specified in IV.11.1 superimposed on the NT1 
input signal, the jitter on the transmitted signal on the NT1 toward the 
network shall conform to following:
.RT
.LP
	a)
	The jitter shall be equal to or less than 0.1 UI
peak\(hyto\(hypeak and less than 0.25\ UI rms when measured with a
high\(hypass filter having a 20\ dB/decade roll\(hyoff below 90\ Hz.
.bp
.LP
	b)
	The jitter in the phase of the output signal relative to
the phase of the input signal (from the network) shall not
exceed 0.12\ UI peak\(hyto\(hypeak or 0.025\ UI rms when measured with
a band\(hypass filter having a 20\ dB/decade roll\(hyoff above 90\ Hz
and a 20\ dB/decade roll\(hyoff below 0.3\ Hz. This applies with
superimposed jitter in the phase of the input signal as
specified in \(sc\ IV.11.1 for single frequency up
to\ F\d2\u\ Hz.
.sp 1P
.LP
IV.11.3\ \ \fITest conditions for jitter measurements\fR 
.sp 9p
.RT
.PP
Due to bidirectional transmission on the 2\(hywire and due to severe intersymbol 
interference no well defined signal transitions are available at 
the NT1 2\(hywire point.
.PP
\fINote\fR \ \(em\ Two possible solutions are proposed:
.RT
.LP
	a)
	A test point in the NT1 is provided to measure jitter an
undisturbed signal.
.LP
	b)
	A standard LT transceiver including an artificial local
line is defined as a test instrument.
.sp 1P
.LP
IV.12\ \ \fITransmitter output characteristics of NT1 and LT\fR 
.sp 9p
.RT
.PP
The following specification apply with a load impedance of
110\ ohms.
.RT
.sp 1P
.LP
IV.12.1\ \ \fIPulse amplitude\fR 
.sp 9p
.RT
.PP
The zero to peak nominal amplitude of the largest pulse shall be
6\ V and the tolerance shall be \(+- | 0%.
.RT
.sp 1P
.LP
IV.12.2\ \ \fIPulse shape\fR 
.sp 9p
.RT
.PP
The pulse shape shall meet the pulse mask of
Figure\ IV\(hy8/G.961.
.RT
.LP
.rs
.sp 30P
.ad r
\fBFigure IV\(hy8/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 1P
.LP
IV.12.3\ \ \fISignal power\fR 
.sp 9p
.RT
.PP
The average power shall be between 14.5 dBm and 17.1 dBm.
.RT
.sp 1P
.LP
IV.12.4\ \ \fIPower spectrum\fR 
.sp 9p
.RT
.PP
The upper bound of the power spectral density shall be within the template 
in Figure\ IV\(hy9/G.961. 
.RT
.LP
.rs
.sp 21P
.ad r
\fBFigure IV\(hy9/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
IV.12.5\ \ \fITransmitter signal nonlinearity\fR 
.sp 9p
.RT
.PP
This is a measure of the deviations from ideal pulse heights and
the individual pulse nonlinearity.
.PP
The deviation between positive and negative pulse heights shall be
less than 5%.
.PP
The measurement method is for further study.
.RT
.sp 2P
.LP
IV.13\ \ \fITransmitter/receiver termination\fR 
.sp 1P
.RT
.sp 1P
.LP
IV.13.1\ \ \fIImpedance\fR \v'3p'
.sp 9p
.RT
.LP
	a)
	The nominal input impedance looking toward the NT1 or LT
respectively shall be 110\ ohms.
.LP
	b)
	The nominal output impedance looking toward the NT1 or LT
respectively shall be less than 30\ ohms when driving pulses,
and shall be 110\ ohms when not driving pulses.
.sp 1P
.LP
IV.13.2\ \ \fIReturn loss\fR 
.sp 9p
.RT
.PP
The return loss of the impedance shall be greater than shown in the template 
Figure\ IV\(hy10/G.961. 
.bp
.RT
.LP
.rs
.sp 21P
.ad r
\fBFigure IV\(hy10/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
IV.13.3\ \ \fILongitudinal conversion loss\fR 
.sp 9p
.RT
.PP
The minimum longitudinal conversion loss shall be greater than
shown in the template Figure 
IV\(hy11/G.961.
.RT
.LP
.rs
.sp 21P
.ad r
\fBFigure IV\(hy11/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce 1000
APPENDIX\ V
.ce 0
.ce 1000
(to Recommendation G.961)
.sp 9p
.RT
.ce 0
.ce 1000
\fBA digital line system for ISDN basic rate access using binary\fR 
.sp 1P
.RT
.ce 0
.ce 1000
\fBbi\(hyphase line code\fR 
.ce 0
.LP
V.0
	\fIElectrical characteristics\fR 
.sp 1P
.RT
.PP
This appendix describes a 160 kbit/s transparent transmission
system using echo cancelling techniques. The transmission rate will support
64\ kbit/s B\ channels and one 16\ kbit/s D\ channel as defined in
Recommendation\ I.412. The remaining 16\ kbit/s capacity will allow for 
framing and auxiliary channel information. 
.PP
Data scrambling is performed on the entirety of the framed data using different 
polynomials at exchange end and subscriber end. Bi\(hyphase coding is 
used for the line code. The encoded signal is filtered and transmitted 
to the line at a symbol rate of 160\ kbauds. The bi\(hyphase signalling 
element 
transitions allow data\(hyderived clock extraction with low jitter, and
equalisation can be accomplished by a short decision\(hyfeedback structure.
Binary decision\(hymaking gives best immunity to residual inter\(hysymbol
interference and residual echo and simplifies receiver design by not requiring 
AGC/decision references. 
.RT
.sp 1P
.LP
V.1
	\fILine code\fR 
.sp 9p
.RT
.PP
For both the directions of transmission the line code is bi\(hyphase. The 
coding scheme is as follows. 
.PP
Binary ZERO is represented by a negative transition in the middle of the 
bit period. 
.PP
Binary ONE is represented by a positive transition in the middle of
the bit period.
.PP
Transitions at the bit boundary occur if successive binary data bits are 
identical. 
.PP
The encoded binary signal is then shaped to effectively filter out the 
high frequency components. 
.RT
.sp 1P
.LP
V.2
	\fISymbol rate\fR 
.sp 9p
.RT
.PP
The symbol rate is determined by the line code, the bit rate of the information 
stream and the frame structure. The symbol rate is 160\ kbauds. 
.RT
.sp 2P
.LP
V.2.1
	\fIClock requirements\fR 
.sp 1P
.RT
.sp 1P
.LP
V.2.1.1\ \ \fINT1 free running clock accuracy\fR 
.sp 9p
.RT
.PP
The accuracy of the free running clock in the NT1 shall be
\(+- | 30\ ppm.
.RT
.sp 1P
.LP
V.2.1.2\ \ \fILT clock tolerance\fR 
.sp 9p
.RT
.PP
The NT1 and LT shall accept a clock accuracy from the ET of
\(+- | 0\ ppm in compliance with Recommendation\ G.703.
.RT
.sp 1P
.LP
V.3
	\fIFrame structure\fR 
.sp 9p
.RT
.PP
The frame structure contains a frame word, \fIN\fR times (2B\ +\ D) and 
a CL channel. 
.PP
As shown in Figure V\(hy1/G.961, a line frame is defined as 40 \*Qcells\*U
C0\ to C39, each containing 19\ bits at the transmission bit rate. Cell C0
contains a frame synchronization pattern.
.PP
Cells C1 to C19 and C21 to C39 contain the subscriber B1, B2, and
D\ channels. Cell C20 contains a CL channel.
.bp
.RT
.LP
.rs
.sp 28P
.ad r
\fBFigure V\(hy1/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
V.3.1
	\fIFrame length\fR 
.sp 9p
.RT
.PP
The defined frame structure and line rate results in a line frame of 760\ 
bits and of 4.75\ ms duration. 
.RT
.sp 1P
.LP
V.3.2
	\fIBit allocation in direction LT\(hyNT1\fR 
.sp 9p
.RT
.PP
As defined in \(sc\ V.3.
.RT
.sp 1P
.LP
V.3.3
	\fIBit allocation in direction NT1\(hyLT\fR 
.sp 9p
.RT
.PP
As defined in \(sc\ V.3.
.RT
.sp 2P
.LP
V.4
	\fIFrame word\fR 
.sp 1P
.RT
.sp 1P
.LP
V.4.1
	\fIFrame word in direction LT\(hyNT1\fR 
.sp 9p
.RT
.PP
The frame word occupies cell C0 in the frame structure, and it
consists of 19\ consecutive ones, which is unique within the frame bit 
sequence. This is ensured by defining the 19th bit in cells\ C1 to\ C39 
to be permanently set to zero. 
.RT
.sp 1P
.LP
V.4.2
	\fIFrame word in direction NT1\(hyLT\fR 
.sp 9p
.RT
.PP
As defined in \(sc\ V.4.1.
.bp
.RT
.sp 1P
.LP
V.5
	\fIFrame alignment procedure\fR 
.sp 9p
.RT
.PP
A 20\(hybit alignment pattern of 19 consecutive ones immediately
preceded by a zero shall be searched for in the incoming data stream. \*QFrame
alignment\*U is defined as the correct reception of three consecutive frames
containing the alignment pattern in the expected positions within the
frames.
.RT
.sp 1P
.LP
V.5.1
	\fIFrame alignment monitoring\fR 
.sp 9p
.RT
.PP
\*QLoss of frame alignment\*U, is defined as the detection of
3\ consecutive frames each with one or more errors in the alignment pattern. 
The monitoring of frame alignment shall be a continuous process. 
.RT
.sp 1P
.LP
V.5.2
	\fILine polarity detection\fR 
.sp 9p
.RT
.PP
In the NT1, a mechanism is provided for the automatic detection of the 
line polarity. An 80\ ms timer is started only by the inactive to active 
transition of the \*Qline signal detect\*U signal, from the transmission 
system. 
The timer is held reset when \*Qframe alignment\*U is achieved. The expiry 
of the timer causes the incoming and outgoing data polarity to be reversed. 
Once the line polarity is determined it is retained as the initial polarity 
for 
subsequent detection operations. The timer duration of 80\ ms is chosen 
to allow for the convergence of the transmission system, plus the time 
required to 
obtain \*Qframe alignment\*U.
.PP
In order to avoid duplication of the alignment pattern by a data
sequence in a data stream from a reversed line, the\ B1, B2 and D\ channels, 
in the LT to NT1 direction, are to be set to all ones during that part 
of the 
activation procedure before operational data is switched through. In addition, 
at least one bit of the auxiliary channel must also be set to a one during 
the activation procedure. 
.RT
.sp 1P
.LP
V.6
	\fIMultiframe\fR 
.sp 9p
.RT
.PP
There is no multiframe structure.
.RT
.sp 1P
.LP
V.7
	\fIFrame offset between LT\(hyNT1 and NT1\(hyLT frames\fR 
.sp 9p
.RT
.PP
The LT\(hyNT1 and NT1\(hyLT frames at the NT1 can be in any alignment but 
the LT is required to align with any offset of the received line frames 
relative to the transmitted line frames.
.RT
.sp 1P
.LP
V.8
	\fICL channel\fR 
.sp 9p
.RT
.PP
The purpose of the CL channel is to convey maintenance information as well 
as \*Qdate valid\*U and \*Qready for data\*U flags. 
.RT
.sp 1P
.LP
V.8.1
	\fIBit rate\fR 
.sp 9p
.RT
.PP
The bit rate of the CL channel is 3.8\ kbit/s.
.RT
.sp 1P
.LP
V.8.2
	\fIStructure\fR 
.sp 9p
.RT
.PP
Figure V\(hy2/G.961 shows the CL channel format in the two directions LT\(hyNT1 
and NT1\(hyLT, which is divided into the following field 
types:
.RT
.LP
	a)
	M3\(hy0: A 4 bit field for the conveyance of a \*Qmaintenance
command\*U to a remote transmission termination. The termination
identity is included in the command coding.
.LP
	b)
	R3\(hy0: A 4 bit field for the conveyance of a \*Qmaintenance
response\*U to the LT.
.LP
	c)
	DV: A \*Qdata valid\*U flag which indicates that, in the LT to
NT1 direction, the\ B1, B2 and D\ channels contain operational
data.
.LP
	d)
	RFD: A \*Qready for data\*U flag which indicates that, in the
NT1 to LT direction, the\ B1, B2 and D\ channels contain
operational data.
.LP
	e)
	D7\(hy0: An 8 bit field for the conveyance of any
\*Qmaintenance data\*U that may be associated with a \*Qmaintenance
response\*U.
.LP
	f
)
	K4\(hy0: A 5 bit cyclic check code which operates on the
auxiliary cell bits A17 to A5 inclusive.
.bp
.LP
.rs
.sp 18P
.ad r
\fBFigure V\(hy2/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
V.8.3
	\fIProtocols and procedures\fR 
.sp 9p
.RT
.PP
Maintenance operations are based on a repetitive
command/echo\(hyresponse protocol. A maintenance operation is initiated by the
continuous transmission of the required \*Qmaintenance command\*U from 
the LT. When the appropriate termination receives the validated command, 
it is continuously echoed back to the LT as a \*Qmaintenance response\*U, 
and the command is acted 
upon. If the command demands data, then this is simultaneously returned 
in the \*Qmaintenance data\*U field. The termination continues to echo 
the command and 
provide any data for as long as it receives appropriate validated commands. 
For responses which are not accompanied by data, the \*Qmaintenance data\*U 
field is 
undefined. The LT assumes the conclusion of the maintenance operation when 
it receives a validated response that matches the transmitted command. 
.PP
Loopbacks are applied using maintenance commands, and transmission
system performance data is returned using the maintenance data field.
Maintenance operations can be performed whenever the Digital Section is
activated.
.RT
.sp 1P
.LP
V.8.4
	\fISecurity\fR 
.sp 9p
.RT
.PP
A security mechanism operates on CL channel bits A17 to A0
inclusive.
.PP
The validation procedure consists of two stages:
.RT
.LP
	a)
	A 5 bit cyclic redundancy code K4\(hy0 operates on CL channel
bits A17 to A5 inclusive. The generator of the code is:
\v'6p'
.sp 1P
.ce 1000
\fIg\fR (\fIx\fR )\ =\ (1
\s11\(ci
\s6+
.PS 10
\fIx\fR )
(1
\s11\(ci
\s6+
.PS 10
\fIx\fR \s11\(ci
\s6+
.PS 10
\fIx\fR \u4\d)
.RT
.ce 0
.sp 1P
.LP
.sp 1
.LP
	This is a Hamming code which gives single bit error
detection and single bit error correction.
.LP
	b)
	A set of CL channel bits A17 to A5 are only accepted as
valid if they have been successfully checked/corrected and they
match the previous two sets which were successfully
checked/corrected. Note that these three sets need not
necessarily have come from consecutive line frames.
.sp 1P
.LP
V.9
	\fIScrambling\fR 
.sp 9p
.RT
.PP
The entirety of the framed binary data stream is scrambled as
follows:
.RT
.LP
	a)
	NT1 to LT scramble polynomial
\v'6p'
.sp 1P
.ce 1000
1 
\s11\(ci
\s6+
.PS 10
\ \fIx\fR \uD\dlF261\u1\d\u4\d
\s11\(ci
\s6+
.PS 10
\ \fIx\fR \uD\dlF261\u1\d\u5\d
.RT
.ce 0
.sp 1P
.LP
.sp 1
.bp
.LP
	b)
	LT to NT1 scramble polynomial
\v'6p'
.sp 1P
.ce 1000
1 
\s11\(ci
\s6+
.PS 10
\ \fIx\fR \uD\dlF261\u1\d
\s11\(ci
\s6+
.PS 10
\ \fIx\fR \uD\dlF261\u1\d\u5\d
.RT
.ce 0
.sp 1P
.LP
.sp 1
	(
\s11\(ci
\s6+
.PS 10
\ =\ EXCLUSIVE OR)
.RT
.sp 1P
.LP
V.10
	\fIActivation/deactivation\fR 
.sp 9p
.RT
.PP
One bit of the CL channel is allocated for use during the
activation and deactivation procedures. These are the \*Qdata valid\*U 
flag in the LT to NT1 direction and the \*Qready for data\*U flag in the 
NT1 to LT direction. These bits are not included in the maintenance protocol 
described above, and 
operate as simple unsollicited indications.
.RT
.sp 1P
.LP
V.10.1\ \ \fISignals used for activation/deactivation\fR 
.sp 9p
.RT
.PP
The signals (SIGs) used for activation/deactivation are:
.RT
.LP
	LT\(hyNT1 direction
.LP
\-v'1P'
.ce
\fBH.T. [T31.961]\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) .
Signal	Frame word	2B + D	M	DV	K
_
.T&
cw(24p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) .
I0	Absent	Absent	Absent	Absent	Absent
.T&
cw(24p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) .
I2	Normal	1	1	0	Normal
.T&
cw(24p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) .
I4	Normal	Normal	Normal	1	Normal
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau [T31.961], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
	NT1\(hyLT direction
.LP
\-v'1P'
.ce
\fBH.T. [T32.961]\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
Signal	Frame word	2B + D	R	RFD	D0\(hyD7	K
_
.T&
cw(24p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
I0\ 	Absent	Absent	Absent	Absent	Absent	Absent
.T&
cw(24p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
I1\ 	0	0	0	0	0	0
.T&
cw(24p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
I31	Normal	0	1	0	Normal	Normal
.T&
cw(24p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
I3\ 	Normal	Normal	Normal	1	Normal	Normal
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau [T32.961], p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
V.10.2\ \ \fIDefinition of internal timers\fR 
.sp 9p
.RT
.PP
The following timers are located within the LT:
.RT
.LP
	\(em
	Timer 2 (T2) prevents unintentional reactivation from the
TE.
.LP
	\(em
	Timer A (TA) is started if, from the layer 1 active state
(LT4), SIG I31 is received, indicating loss of SIG\ I3. If
SIG\ I3 is not subsequently received before expiry of Timer\ A,
deactivation is initiated.
.LP
	\(em
	Timer B (TB) is started upon loss of framing. If frame
recovery is not achieved before expiry of Timer\ B, deactivation
is initiated.
.PP
Durations of internal timers are for further study.
.sp 1P
.LP
V.10.3\ \ \fIDescription of activation/deactivation procedures\fR 
.sp 9p
.RT
.PP
Figure V\(hy3/G.961 (sheet 1 of 3) illustrates the method of
activation from the network. PH ACTIVATE REQUEST causes SIG\ I2 to be
transmitted from the network towards NT1. NT1 achieves line signal detect 
and frame synchronization status. At this point NT1 sends INFO\ 2 towards 
the TE and simultaneously sends SIG\ I31 towards the network. In time, 
the network achieves in synchronization status and the TE replies to INFO\ 
2 with INFO\ 3. The latter event is signalled to the network from NT1 by 
sending SIG\ I3. At the network 
this results in ACTIVATE INDICATION. The network responds by sending SIG\ I4
towards NT1. Upon receipt of this signal NT1 sends INFO\ 4 towards the 
TE, thus completing the activation procedure. 
.bp
.PP
Figure V\(hy3/G.961 (sheet 2 of 3) illustrates activation from the user 
side. The activation process is essentially similar to that for activation 
from the network side, except that INFO\ 1 from the TE begins the process. 
In this 
case NT1 starts the process by sending SIG\ I1 towards the network. Line 
signal detect status is achieved at the network. The network sends SIG\ 
I2 towards NT1. From here on the process is as described above. 
.PP
Figure V\(hy3/G.961 (sheet 3 of 3) illustrates the method of
deactivation. DEACTIVATE REQUEST causes transmission from the network to 
NT1 to cease (SIG\ I0). The NT1, on detecting this, sends SIG\ I1 back 
to the network, and INFO\ 0 towards the TE. The TE responds by sending 
INFO\ 0 back to the NT1, and on receipt of this, the NT1 ceases transmitting 
to the network (SIG\ I0). At the network, this results in DEACTIVATE INDICATION, 
thus completing the 
deactivation procedure.
.PP
Definitions for SIGs are given in V.10.1 and for definitions for INFOs 
refer to Recommendation\ I.430. 
.RT
.LP
.rs
.sp 36P
.ad r
\fBFigure V\(hy3/G.961 (feuillet 1 sur 3), p.20\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 47P
.ad r
\fBFigure V\(hy3/G.961 (feuillet 2 sur 3), p.21\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 27P
.ad r
\fBFigure V\(hy3/G.961 (feuillet 3 sur 3), p.22\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
V.10.4\ \ \fIState transition table for NT1 as a function of INFOs, SIGs\fR 
.sp 9p
.RT
.PP
See Table V\(hy1/G.961.
.RT
.sp 1P
.LP
V.10.5\ \ \fIState transition table for LT as a function of FEs, SIGs, and\fR 
\fIinternal timers\fR 
.sp 9p
.RT
.PP
See Table V\(hy2/G.961.
.RT
.sp 1P
.LP
V.10.6\ \ \fIActivation times\fR 
.sp 9p
.RT
.PP
Metallic pair cable transmission system.
.PP
Maximum activation time occurring immediately after a deactivation
(without intervening loopback or powering action):
.RT
.LP
	a)
	without\ regenerator:
	100 ms;
.LP
	b)
	with\ regenerator:
	200 ms.
.PP
Maximum activation time occurring after the first powering of a
line:
.LP
	a)
	without\ regenerator:
	250 ms;
.LP
	b)
	with\ regenerator:
	500 ms.
.sp 1P
.LP
V.11
	\fIJitter\fR 
.sp 9p
.RT
.PP
Jitter tolerances are intended to ensure that the limits of
Recommendation\ I.430 are supported by the jitter limits of the transmission
system on local lines.
.bp
.RT
.ce
\fBH.T. [T33.961]\fR 
.ce
TABLE\ V\(hy1/G.961
.ce
\fBNT1 activation/deactivation state transition table\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(78p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
States	NT1  Deact.	NT2  Act. pendg.	NT3  Systm. act.	NT4  Wait data valid	NT5  Layer 1 act.
_
.T&
cw(36p) | cw(42p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) .
Events	SIG transmitted	I0	I1	I31	I3	I3
_
.T&
cw(30p) | cw(48p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) , ^  | c | c | c | c | c | c 
^  | c | c | c | c | c | c.
SIG received	I0  (Deact. req.)	\(em	\(em	I0  NT1	I0  NT1	I0  NT1
	I2  (Act. req.)	I2  NT3	I2  NT3	\(em	\(em	I2  NT3	I4  (Dat. valid)	/	I2  NT3	/	I4  NT5	\(em
_
.T&
cw(30p) | cw(48p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) , ^  | c | c | c | c | c | c 
^  | c | c | c | c | c | c.
From  TE	I0  (Deact. ind.)	\(em	I0  NT1	\(em	\(em  NT3	I2  NT3
	I1  (Act. req.)	\(em  NT2	\(em	/	/	/	I3  (Act. ind.)	\(em  NT2	\(em	\(em  NT4	\(em	\(em
.TE
.LP
/
No change
.LP
\(em
Impossible
.nr PS 9
.RT
.ad r
\fBTableau V\(hy1/G.961 [T33.961], p.23\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 18
.bp
.ce
\fBH.T. [T34.961]\fR 
.ce
TABLE\ V\(hy2/G.961
.ce
\fBLT activation/deactivation state transition table\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(66p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) .
States	LT1  Deact.	LT2  Wait for systm. act	LT3  Systm act.	LT4  Layer 1 act.	LT5  Loss of framg.	LT6  Wait for deact.
_
.T&
cw(30p) | cw(36p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) .
Events	SIG transmitted	I0	I2	I2	I4	(Note)	I0
_
.T&
cw(24p) | cw(42p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) , ^  | c | c | c | c | c | c | c 
^  | c | c | c | c | c | c | c 
^  | c | c | c | c | c | c | c.
SIG received	I0  (Deact. ind.)	\(em	\(em	FE7  \(em	FE7  \(em	\(em	FE6  LT1
	I1  (Act. req.)	FE2  TL2	\(em	/	/	/	\(em	I31  (System activated)	/	FE3  LT3	\(em	Start TA  LT3	/	\(em	I3  (Layer\ 1 activated)	/	/	Stop TA  FE4  LT4	\(em	/	\(em
_
.T&
cw(24p) | cw(42p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) , ^  | c | c | c | c | c | c | c 
^  | c | c | c | c | c | c | c 
^  | c | c | c | c | c | c | c 
^  | c | c | c | c | c | c | c.
Internal event	Loss of framing	/	/	Start TB  LT5	Start TB  LT5	/	\(em
	Frame recovery	/	/	/	/	Stop TB  LT3	\(em	Expiry of timer 2	\(em	\(em	\(em	\(em	\(em	FE6  LT1	Expiry of timer A	\(em	\(em	Start T2  FE7  LT6	\(em	\(em	\(em	Expiry of timer B	\(em	\(em	\(em	\(em	Start T2  FE7  LT6	\(em
_
.T&
cw(24p) | cw(42p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) | cw(30p) | cw(24p) , ^  | c | c | c | c | c | c | c.
Function element received	FE1	\(em  LT2	/	/	/	/	\(em  LT2
	FE5	\(em	Start T2  LT6	Start T2  LT6	Start T2  LT6	Start T2  LT6	\(em
.LP
\(em
No change
.LP
/
Impossible
.LP
\fINote\fR
\ \(em\ The SIG transmitted by the LT when framing is lost will not change
from that transmitted immediately prior to the loss (i.e. I2 or\ I4).
.nr PS 9
.RT
.ad r
\fBTableau V\(hy2/G.961 [T34.961], p.24\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 4
.bp
.LP
\fIMeaning of symbols for Tables V\(hy1/G.961 and V\(hy2/G.961\fR 
.sp 1P
.RT
.sp 2P
.LP
States at NT
.sp 1P
.RT
.sp 1P
.LP
NT1
	Deactivated
.sp 9p
.RT
.LP
NT2
	Activation pending
.LP
NT3
	Transmission system activated
.LP
NT4
	Wait for data valid
.LP
NT5
	Layer 1 activated
.sp 2P
.LP
States at LT
.sp 1P
.RT
.sp 1P
.LP
LT1
	Deactivated
.sp 9p
.RT
.LP
LT2
	Waiting for transmission system activation
.LP
LT3
	Transmission system activated
.LP
LT4
	Layer 1 activated
.LP
LT5
	Loss of framing
.LP
LT6
	Waiting for deactivate indication
.LP
ST.T2
	Start timer T2
.LP
STP.TA
	Stop timer TA
.sp 1P
.LP
Function element definitions are as in Recommendation G.960.
.sp 9p
.RT
.sp 1P
.LP
V.11.1\ \ \fINT1 input signal jitter tolerance\fR 
.sp 9p
.RT
.PP
For further study.
.RT
.sp 1P
.LP
V.11.2\ \ \fINT1 output jitter limitations\fR 
.sp 9p
.RT
.PP
For further study.
.RT
.sp 1P
.LP
V.11.3\ \ \fITest conditions for jitter measurements\fR 
.sp 9p
.RT
.PP
For further study.
.RT
.sp 2P
.LP
V.12
	\fITransmitter output characteristics of NT1 and LT\fR 
.sp 1P
.RT
.PP
The following specifications apply with a load impedance of
140\ ohms.
.RT
.sp 1P
.LP
V.12.1\ \ \fIPulse amplitude\fR 
.sp 9p
.RT
.PP
The nominal peak amplitude of a transmitted signal pulse shall be 1.6\ 
V, and the tolerance shall be \(+- | %. 
.bp
.RT
.sp 1P
.LP
V.12.2\ \ \fIPulse shape\fR 
.sp 9p
.RT
.PP
The pulse shape shall be as shown in Figure V\(hy4/G.961.
.RT
.LP
.sp 3
.rs
.sp 31P
.ad r
\fBFigure V\(hy4/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
.sp 1P
.LP
V.12.3\ \ \fISignal power\fR 
.sp 9p
.RT
.PP
The maximum total transmit power, averaged in any one second
period, sent down to the line shall be +10\ dBm.
.bp
.RT
.sp 1P
.LP
V.12.4\ \ \fIPower spectrum\fR 
.sp 9p
.RT
.PP
The upper bound of the power spectral density, averaged in any one second 
period in any 3\ kHz band, shall be limited as shown in the template 
Figure\ V\(hy5/G.961.
.RT
.LP
.sp 1
.rs
.sp 32P
.ad r
\fBFigure V\(hy5/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
.sp 1
V.12.5\ \ \fITransmitter signal nonlinearity\fR 
.sp 9p
.RT
.PP
This is a measure of the deviations from ideal pulse heights and
the individual pulse nonlinearity. For further study.
.RT
.sp 2P
.LP
V.13
	\fITransmitted/receiver termination\fR 
.sp 1P
.RT
.sp 1P
.LP
V.13.1\ \ \fIImpedance\fR 
.sp 9p
.RT
.PP
The nominal line driving impedance shall be 140 ohms.
.bp
.RT
.sp 1P
.LP
V.13.2\ \ \fIReturn loss\fR 
.sp 9p
.RT
.PP
The return loss of the impedance (against 140 ohms) shall be
greater than shown in the template Figure\ V\(hy6/G.961.
.RT
.LP
.sp 1
.rs
.sp 21P
.ad r
\fBFigure V\(hy6/G.961, p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 1
.sp 1P
.LP
V.13.3\ \ \fILongitudinal conversion loss\fR 
.sp 9p
.RT
.PP
This is a measure of the immunity from longitudinal voltages. In
the frequency band 100\ Hz to 256\ kHz, the conversion loss shall not be less
than 46\ dB. From 256\ kHz to 4\ MHz, the conversion loss shall not be 
less than [46 \(em 40\ log\d1\\d0\u(\fIf\fR /256)] dB (where\ \fIf\fR is 
frequency in kHz). 
.RT
.LP
.rs
.sp 17P
.ad r
Blanc
.ad b
.RT
.LP
.bp