Remote alarm transfer method and system

An asynchronous transfer mode communication system including an asynchronous transfer mode network including a plurality of asynchronous transfer mode cross-connect units;

• a first communication station provided on an upstream side of said asynchronous transfer mode network;
• and a second communication station provided on a downstream side of said asynchronous transfer mode network, each of said asynchronous transfer mode cross connect units comprising:
• abnormality detecting means, coupled to a first input signal path on the upstream side, for outputting a detection signal when an abnormality is detected in the first input signal path;
• synchronization error detecting means, coupled to the first input signal path, for outputting a detection signal when a synchronization error is detected in a signal received via the first input signal path;
• alarm indication signal cell generating means, coupled to said abnormality detecting means and to said synchronization error detecting means, for generating an alarm indication signal when the detection signal is received from at least one of said abnormality detecting means and said synchronization error detecting means;
• alarm indication signal cell detecting means, coupled to the first input signal path, for outputting an alarm indication signal when said alarm indication signal is received via the first input signal path;
• remote alarm transfer cell generating means, coupled to said abnormality detecting means, to said synchronization error detecting means and to said alarm indication signal cell detecting means, for generating a remote alarm transfer signal which indicates a failure based on said detection and alarm indication signals from said abnormality detecting means, said synchronization error detecting means and said alarm indication signal cell detecting means;
• path setting table means for prestoring output signal paths and a remote alarm transfer path for transferring the remote alarm transfer signal to said first communication station;
• and
• control means coupled to said alarm indication signal cell generating means, to said remote alarm transfer cell generating means, to said path setting table means, to a second input signal path on the downstream side and to first and second output signal paths respectively on the upstream and downstream sides, for transferring the remote alarm transfer signal, in response to said failure, to said first communication station via the first output signal path on the upstream side according to the remote alarm transfer path set in said path setting table means,
• said path setting table means prestoring said output signal paths with respect to each of the input signal paths.

An asynchronous transfer mode cross-connect method for use in an asynchronous transfer mode communication system, said asynchronous transfer mode communication system includes at least two communication stations which are coupled via a plurality of asynchronous transfer mode cross-connect units, said asynchronous transfer mode cross-connect method comprising the steps of:

• (a) outputting a first detection signal from one of said asynchronous transfer mode cross-connect units when an abnormality is detected in a first input signal path;
• (b) outputting a second detection signal from said one of said asynchronous transfer mode cross-connect units when a synchronization error is detected in a signal received via the first input signal path;
• (c) generating an alarm indication signal within said one of said asynchronous transfer mode cross-connect units when at least one of the first and second detection signals is output;
• (d) generating a remote alarm transfer signal which indicates a failure based on a) the first and second detection signals and b) an alarm indication signal which is received via the first input signal path;
• and
• (e) transferring the remote alarm transfer signal, in response to the failure, to a transmitting communication station via a first output signal path according to a remote alarm transfer path set in a path setting table in which an output signal path is also set with respect to each input signal path.