Patent ID: 7359410
Filing Date: 2008-04-15
Classification: H04J

Abstract:
1. A SONET multiplexer comprising: a first OC3 port operable to receive and transmit optical signals; a second OC3 port operable to receive and transmit optical signals; at least one DS3 port operable to receive and transmit electrical signals; a first optical interface to receive an optical signal via said first OC3 port and convert it into an electrical signal; a second optical interface to receive an optical signal via said second OC3 port and convert it into an electrical signal; a SONET synchronizer operable to evaluate bits in said electrical signal received from a selected one of said first optical interface and said second optical interface and detect at least one of a plurality of SONET conditions comprising loss of signal, loss of frame and out of frame; a SONET overhead terminator configured to locate SONET frames in said electrical signal received from said selected optical interface and extract selected overhead bytes in said SONET frames; a mapper operable to use data from said electrical signal received from said selected optical interface and said selected overhead bytes to generate a plurality of DS3 streams; a line interface unit operable to convert the said DS3 streams into respective analog signals for transmission from said at least one DS3 port, said line interface unit being operable to receive analog signals via said at least one DS3 port and convert them to corresponding digital signals, said mapper being operable to format said digital signals as a SONET stream, said SONET overhead terminator being operable to append selected overhead bytes to said SONET stream, and said SONET synchronizer being operable to prepare said SONET stream for transmission via a selected one of said first optical interface and said second optical interface and the corresponding one of said first OC3 port and said OC3 second port; and a processing device operable in conjunction with said mapper, said SONET overhead terminator, said SONET synchronizer, said first optical interface and said second optical interface to perform switch protection using said first OC3 port and said second OC3 port, respectively, as one of a primary circuit and a protection circuit.