EDIT BY : S.ROKHSATI

Telecommunication Infrastructure Company

K4304-AC PCM30 ANALYZER

Prerequisite :

PCM BASICPCM ALARM’SSIGNALING (CAS & NO.7)CRCG.821M.2100PBRS

ALARM’S IN K4304

‘AIS’ ALARM INDICATION SIGNAL‘NOSIGN’ NO INPUT SIGNAL‘NOSYNC’ NO FRAME ALIGNMENT‘NOMSYNC’ NO MULTIFRAME ALIGNMENT‘RAI’ REMOT ALARM INDICATION‘MRAI’ DISTANT LOSS OF MULTIFRAME ALIGNMENT‘NO CRC4’ NO CRC4 ALIGNMENT‘NOPRBS’ NO PRBS SYNC

The recommendation G.821 Error performance of an international digital connection operating at a bit rate below the primary rate and forming part of an integrated services digital network of ITU-T is an international agreement on the transmission quality of lines of telephone network , which for the transmission of digital data to be used. Phone lines are, whether they as local loop are installed in the local area, or whether they are inside the network abroad telephone traffic used, not always suitable for the data transmission. It therefore had to be found and agreed technical criteria by which one could judge the suitability of a telephone line for data transmission, and also measurement methods by which you could check these criteria. The most important criterion was agreed on the bit error rate . It an agreement has been reached, that when a bit error rate of 10 -4 a line for analog voice transmission is still quite suitable, but at 10 -3 a line would be completely unusable. The bit error rate of 10 -3 is set equal to a complete loss of signal, in which instead of the useful signal, the erroneous indication alarm signal (AIS) is inserted into the line. For digital voice transmission over the ISDN , and for data transmission, the transmission quality of a line but it should be so much that bit errors with a frequency of less than 10 -6 occur. These criteria and the appropriate quality parameters have been worked out in detail in Recommendation G.821. multiplexers and other devices in the digital transmission technique to measure these parameters continuously and capture them in a (performance) - database (MIB).

G.821

PRBS

DESCRIPTION OF MEASURMENT RESULTS:

ELAP

FAS

CODE

CRC4

REM.CRC4

PEAK +CODE-CODE

FREQUENCY,HZ

CAS

MFAS

RESULT IN G.821: PASS OR FAIL

US

ES

SES

DM