Priority Quality Level


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
SSM

DS1
Standard
Flag

 

E1

Description

E1
SSM

E1
Standard
Flag

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