XRT86VL38
PRELIMINARY
xr
OCTAL T1/E1/J1 FRAMER/LIU COMBO
REV. P1.0.6
417
13.4
T1 Super Frame Format (SF)
The Superframe Format (SF), is also referred to as the D4 format. The requirement for associated signaling in
frames 6 and 12 dictates that the frames be distinguishable. This leads to a multiframe structure consisting of
12 frames per superframe (SF) as shown in Figure 114 and Table 189. This structure of frames and
multiframes is defined by the F-bit pattern. The F-bit is designated alternately as an Ft bit (terminal framing bit)
or Fs bit (signalling framing bit). The Ft bit carries a pattern of alternating zeros and ones (101010) in odd
frames that defines the boundaries so that one timeslot may be distinguished from another. The Fs bit carries
a pattern of (001110) in even frames and defines the multiframe boundaries so that one frame may be
distinguished from another.
F
IGURE
114. T1 S
UPERFRAME
PCM F
ORMAT
T
ABLE
189: S
UPERFRAME
F
ORMAT
F
RAME
B
IT
F-B
ITS
B
IT
U
SE
IN
E
ACH
T
IMESLOT
S
IGNALLING
C
HANNEL
T
ERMINAL
F
RAMING
F
T
T
ERMINAL
F
RAMING
F
S
T
RAFFIC
S
IG
1
0
1
----
1-8
----
----
2
193
----
0
1-8
----
----
3
386
0
----
1-8
----
----
4
579
----
0
1-8
----
----
5
772
1
----
1-8
----
----
6
965
----
1
1-7
8
A
7
1158
0
----
1-8
----
----
8
1351
----
1
1-8
----
----
B
A
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
8 Bits per Timeslot
Ft
or
Fs
Ft
or
Fs
TS
1
TS
1
TS
2
TS
2
------------------
------------------
TS
13
TS
13
-------------------
-------------------
TS
24
TS
24
FR
1
FR
1
FR
2
FR
2
------------------
------------------
FR
7
FR
7
-------------------
-------------------
FR
11
FR
11
FR
12
FR
12
Signalling Information
Bit 7
During:
Frame 12
Frame 6
24 Timeslots per Frame
Frame = 193 Bits
Multiframe
SF = 12 Frames