Background: Know: Recognize:
Anticipates: Alarms, Fault management
Error codingEditSignal must be encoded to eliminate transmission error. In layer 2, Link layer , Hamming coding is used for this purpose. Hamming weight and distance are calculated and are used to detect and/or correct errors.
In network management, fault management is the set of functions that detect, isolate, and correct malfunctions in a telecommunications network, include maintaining and examining error code, accepting and acting on error detection notifications, tracing and identifying faults, correcting faults.
Codebook is used to map problems against symptoms, if codebook is bigger then more symptoms can be analysed and there is better mapping between problems and symptoms. When transmission errors occur, network management systems will often send a notification to the network operator using a protocol such as SNMP.
An alarm is a persistent indication of a fault until the triggering condition has been resolved. A current list of problems occurring on the network component is often kept in the form of an active alarm list. A list of cleared faults is also maintained by most network management systems.
There is a procedure called error control coding to keep the probability of transmission errors at an acceptably low level. The error control coding divides into two task: error detection and error correction.
The aim of error detection is to decide whether the received word is a code word or not. In the case of error correction, the receiver is able to correct certain errors.
Any error-correcting code can be used for error detection. Using minimum-distance-based error-correcting codes for error detection can be suitable if a strict limit on the minimum number of errors to be detected is desired.