In the evaluation of the QoS (quality of service) of digital networks, not
only the management and operation of the network, but also the development
of a new service menu must be considered important factors. Among them, the
user information error ratio is the most essential item. This paper consid
ers QoS monitoring of a digital backbone network that will support future c
ommunication services, and proposes a new method for determining the user i
nformation error ratio. The proposed method performs error monitoring by tr
ansmitting the error-detecting code generated by the sending side to the re
ceiving side through a channel which is different from the channel used for
user information, and realizes highly accurate in-service end-to-end error
monitoring for any kind of user link. This paper analyzes the requirements
for user information error monitoring. The operating principles and a char
acteristics analysis of the proposed method are presented, revealing the mo
nitoring performance of the system. Finally, the method is applied and desi
gn examples are presented, demonstrating the usefulness of the proposed met
hod. (C) 2001 Scripta Technica.