TR TSY 000191 : ISSUE 1

1.0 Introduction
1.1 Purpose of Document
1.2 Definitions
1.3 Scope
1.4 Organization of Document
2.0 Purpose and General Application Requirements for
          AIS
2.1 Purpose of AIS
2.2 Maintenance Span Characterization
2.3 Maintenance Spans and AIS Application
2.4 Transparency
3.0 Format of Alarm Indication Signals
3.1 AIS Formats for Use Between Maintenance Spans
3.2 Notes on AIS Formats
3.3 AIS Electrical Requirements
3.4 AIS Formats for Use Within Maintenance Spans
4.0 AIS Related Actions and the Sequence of AIS
          Events
4.1 AIS-Related Actions
4.2 Sequence of AIS-Related Events
5.0 Definition of and Timing for AIS Events
5.1 Detection of Failures that are to Cause the
          Activation of AIS
5.1.1 Loss of Signal
5.1.2 Out-of-Frame
5.1.3 Internal Equipment Failure
5.2 Failure Condition Detection Times
5.3 AIS Activation Times
5.4 Detection of Incoming AIS
5.4.1 Identification of DS1, DS1C, or DS2 Full-Channel
          AIS
5.4.2 Identification of DS3 Full-Channel AIS
5.4.3 Identification of DS1 Embedded Alarm Channel AIS
5.5 Incoming AIS Detection Time
5.6 Detection of Good Signals That Are To Cause the
          Deactivation of AIS
5.6.1 Ones Density Requirements
5.6.2 In-Frame Requirements
5.6.3 Acceptable Internal Equipment Conditions
5.7 Good Signal Detection Time (Shown on Figure 3 as
          "Failure Condition Detected - No")
5.8 AIS Deactivation Time
6.0 Glossary
7.0 References
LIST OF FIGURES
Figure 1 Maintenance Spans
Figure 2 Sequence of Events
Figure 3 Timing of Events

Provides Bellcore's view of proposed generic requirements for the application of Alarm Indication Signals (AIS) in a typical BOC digital network. AIS formats and specific digital signal rates are defined as well as the conditions under which an AIS is to be activated and deactivated. It also indicates the action to be taken by network equipment when an AIS is detected as an incoming signal.