Symmetricom, Inc. has defined Priority Quality Level (PQL) values to allow translation of SSM values for mixed carrier (DS1 and E1) environments. The SSM to PQL translation is performed by the input when SSM signals are received. The PQL to SSM translation is performed by the DS1/E1 output when SSMs are generated.
PQLs allow the system to compare and rate the signal quality from different sources, and provide an effective way for it to communicate the quality of output signals. The table below provides factory default PQL settings.
PQL |
DS1 Description |
DS1 |
DS1 |
E1 Description |
E1 |
E1 |
1 |
|
0xFF |
|
|
0xFF |
|
2 |
PRS |
0x04 |
S |
|
0x02 |
|
3 |
|
0x04 |
|
PRC/G.811 |
0x02 |
S |
4 |
STU |
0x08 |
S |
STU |
0x00 |
S |
5 |
ST2 |
0x0C |
S |
Type II |
0x04 |
|
6 |
Type V |
0x78 |
S |
Type V |
0x04 |
S |
7 |
Type I |
0xFF |
|
Type I |
0xFF |
|
8 |
ST3E |
0x7C |
S |
Type III |
0x08 |
|
9 |
Type VI |
0x10 |
|
Type VI |
0x08 |
S |
10 |
ST3 |
0x10 |
S |
Type IV |
0x0B |
|
11 |
|
0x22 |
|
G.813 Opt 1 |
0x0B |
S |
12 |
SMC |
0x22 |
S |
G.813 Opt 2 |
0x0F |
|
13 |
ST4 |
0x28 |
S |
|
0x0F |
|
14 |
Reserved |
0x40 |
S |
|
0x0F |
|
15 |
DUS |
0x30 |
S |
DUS |
0x0F |
S |
16 |
? |
0x7E |
S |
? |
0x0F |
|