US 5,479,608 A · Group facility protection in a digital telecommunications system

Abstract

A telecommunications system having 1:n group facility protection is disclosed. Two cross-connects are provided, each organized in a distributed fashion, and which have a group of member ports bidirectionally coupled to one another in corresponding fashion via a plurality of paths, such as of the DS-3 data frame type. Each of the cross-connects also include a bidirectional protection port, coupled to the protection port of the other cross-connect by way of a protection path, also preferably of the DS-3 type; the protection port for each cross-connect is assigned to the member port group, and is implemented to be managed by the same distributed interface processing unit as the protected member port group. The cross-connects monitor their member input ports for received facility errors, such as signal failures or excessive failure rates, and request a third-stage bridge from its mate cross-connect in the event of such error. Upon receipt of a good signal at the protection input port, the requesting cross-connect effects a first stage switch, so that the previously failing facility is received over the protection path. Communication of request and acknowledge signals over the protection path is preferably by way of the C-bit and X-bit channels, for DS-3 paths. The switch preferably reverts to the normal condition responsive to the facility becoming valid for a timeout period at the original member port.

Claims13

Dependent claims

A method of providing facility protection by way of a protection path assigned to a plurality of bidirectional member paths between first and second nodes in a telecommunication system, said first and second nodes having a plurality of member ports for communicating a plurality of facilities along said member paths, and having protection ports for communicating a protection facility along said protection path, comprising the steps of:

detecting an error condition in the facility received at a first member input port of said first node from a first member output port of said second node;
responsive to said detecting step, transmitting a bridge request from said protection port of said first node to said second node;
responsive to said transmitting step, bridging the facility from said first member output port of said second node to a protection output port of said second node coupled to said protection path;
and
after said bridging step, switching said first node to receive the facility from a protection input port of said first node coupled to said protection path.

2 more elements

A cross-connect system having group facility protection, comprising:

a plurality of member input ports and member output ports arranged in pairs, so that each member input port and a corresponding member output port are bidirectionally coupled to a path;
a protection input port and a protection output port, coupled to a protection path and assigned to said plurality of member input ports and member output ports;
a central processing unit, coupled to a bus;
a cross-connect matrix, coupled to said bus;
an interface processing unit coupled to said bus, to said member input and output ports, and to said protection input port and protection output port, said interface processing unit for providing the steps of:
monitoring said member input ports to detect an error condition;
requesting a bridge from said network responsive to a detected error condition at a first one of said member input ports;
and
switching to connect said protection input port to said first member input port to receive the facility thereat, after said requesting step.

6 more elements

A telecommunications system, comprising:

a first cross-connect, comprising:
a plurality of member input ports and member output ports arranged in pairs, each member input port corresponding to a member output port;
a protection input port and a protection output port, both assigned to said plurality of member input ports and member output ports;
and
an interface processing unit coupled to said member input and output ports, and to said protection input port and protection output port, said interface processing unit for:
monitoring said member input ports to detect an error condition;
issuing a bridge request signal from said protection output port responsive to a detected error condition at a first one of said member input ports;
and
switching to connect said protection input port to said first member input port to receive the facility thereat, after said issuing step;
and
a plurality of paths, comprising a plurality of member communications paths coupled to said plurality of member input ports and member output ports of said first cross-connect, and a protection communication path coupled to said protection input port and said protection output port of said first cross-connect;
a second cross-connect, comprising:
a plurality of member input ports and member output ports arranged in pairs, so that each member input port and a corresponding member output port are bidirectionally coupled to a corresponding member output port and member input port, respectively, of said first cross-connect, via a corresponding one of said plurality of member communications paths;
a protection input port and a protection output port, both assigned to said plurality of member input ports and member output ports, and coupled to said protection output port and said protection input port, respectively, of said first cross-connect, via said protection path;
an interface processing unit coupled to said member input and output ports, and to said protection input port and protection output port, said interface processing unit for:
responsive to said bridge request signal, bridging the facility from the first member output port of said second cross-connect to the protection output port of said second cross-connect.

13 more elements

Dependencies are inferred from the claim text.

Group facility protection in a digital telecommunications system

Life of this patent

Group facility protection in a digital telecommunications system

Life of this patent

Abstract

Claims13