Protection arrangement for an optical transmitter/receiver device

Claim 2

Protection arrangement according to claim 1, in which said spare optical transmit module (STM) includes : - switching means (S) having n inputs connected to respective inputs (I1/In) of said optical transmitter circuits (LC1/LCn); - fault evaluating means (FE) connected to said optical transmitter circuits (LC1/LCn) and having an output on which a control signal (C) indicative of said defective optical transmit circuit (LCi) is produced, said control signal (C) controlling said switching means (S) in such a way that the latter provide at their output said input signal (Ii); and - a spare transmit circuit (STC) which is connected to the output of said switching means (S) and in response to said input signal (Ii) generates said optical signal (OS) at its output which constitutes the output of said module (STM).

Claim 3

Protection arrangement (Fig. 1) according to claim 2 in which if said defective optical transmit circuit is out of service, said routing means (R) consist of : - an n port wavelength demultiplexer (WDM), whose input is connected to the output of said spare transmit circuit (STC) which is tunable and tuned by a second control signal (CA) produced by said fault evaluating means in such a way that it produces said optical signal (OS) with a wavelength (li) characteristic for said defective circuit (LCi); and - n 2-by-1 optical power combiners (OPC1/OPCn) having first inputs connected to respective outputs of said optical transmitter circuits (LC1/LCn) and having second inputs connected to respective outputs of said n-ports wavelength demultiplexer (WDM), the outputs of said combiners constituting said output terminals (O1/On).

Claim 4

Protection arrangement according to claim 2 in which, if said defective optical transmitter circuit is out of service, said routing means (R) include : - n 2-to-1 optical power combiners (OPC1/OPCn) whose first inputs are connected to respective outputs of said optical transmitter circuits (LC1/LCn); and - a 1-to-n switch to switch the output of said spare optical transmit circuit (STC) to the second input of the 2-to-1 optical power combiner (OPCi) connected to said defective optical transmit circuit, said 1-to-n switch being controlled by said control signal (C).

Claim 5

Protection arrangement (Figs 5, 6) according to claim 2, in which said routing means (R) include : - n 2-to-1 switches (S11/S1n) each with a first input, a second input and an output, the first inputs being connected to one of said optical transmitter circuits (LC1/LCn); and - a 1-to-n optical splitter (SP) to couple the output of said spare optical transmit circuit (STC) to the second inputs of said n 2-to-1 switches, each of said n 2-to-1 switches being controlled by said control signal (C) in such a way that it switches to said second input if the optical transmitter circuit connected to said first input is defective.

Claim 6

Protection arrangement (Fig. 1, 5) according to claim 2, in which said fault evaluating means (FE) include: - n test circuits (OBC1/OBCn) which are each part of a respective one of said optical transmitter circuits (LC1/LCn) and able to test the working thereof and to accordingly provide a test result signal (C1/Cn) on its output; and - an interpretation module (IM) having n inputs connected to the outputs of said test circuits (OBC1/OBCn) and having an output on which said control signal (C) is provided.

Claim 7

Protection arrangement (Fig. 6) according to claim 2, in which said fault evaluating means (FE) is constituted by a fault evaluating circuit which has n inputs/outputs connected to respective ones of said optical transmitter circuits (LC1/LCn) and which is able to test the working thereof, and with an output at which said control signal (C) is provided.

Claim 8

Protection arrangement for an optical receiver device (RX) having n optical receive circuits (RX1/RXn) whose outputs (ES1/ESn) are coupled to respective ones of n output terminals (01/0n), said protection arrangement including : - a spare optical receive module (SRM) whose n inputs are constituted by the inputs of said optical receiver device (RX), said spare optical receive module (SRM) interworking with said optical receive circuits (RX1/RXn) and having an output (ES) at which, if any one (RXi) of said optical receive circuits is defective, an electrical signal (ES) characteristic of that defective optical receive circuit (RXi) is produced said electrical signal carrying the same information as carried by an input signal (Ii) applied to the input of said defective optical receive circuit; and - routing means (R) which are connected to the outputs (ES1/ESn) of said optical receive circuits (RX1/RXn) and to the output (ES) of said spare optical receive module (SRM) and which provide said electrical signal (ES) at the output terminal to which the output of said defective optical receive circuit (RXi) is connected.

Claim 9

Protection arrangement according to claim 8, in which said spare optical receive module (SRM) includes : - switching means (S) having n inputs constituting the input terminals of the receiver device, n outputs connected to respective inputs of said optical receive circuits (RX1/RXn) and a further output on which at least said input signal (Ii) applied to said defective optical receive circuit (RXi) is provided; - fault evaluating means (FE) which are connected to said optical receive circuits (RX1/RXn) and produce at their output a control signal (C) indicative of said defective receiver circuit (RXi), said control signal (C) controlling said routing means (R); - a spare receive circuit (SRC) which is connected to the further output of said switching means (S), and which in response to said input signal (Ii) generates said electrical signal (ES) at its output which constitutes the output of said module (SRM).

Claim 10

Protection arrangement (Figs 7, 8, 9) according to claim 9, in which said routing means (R) include n 2-to-1 switches (S11/S1n) each with an output connected to one of said output terminals (O1/On), with a first input connected to the output of one of said optical receive circuits (RX1/RXn) and a second input connected to the output of said spare optical receive module (SRM), said n 2-to-1 switches being controlled by said control signal (C).

Claim 11

Protection arrangement (Fig. 7) according to claim 9, in which said switching means (S) comprise : - n optical splitters (SP1/SPn) to each of which a respective one of n received signals (I1/In) is applied and each of which has a first output connected to the input of a respective one of said optical receive circuits (RX1/RXn); and - an optical power combiner (OPC) with n inputs each of which is connected to a second output of said optical splitters (SP1/SPn) and producing at its output the combination of said input signals (I1/In), while said optical receive circuits (RX/RXn) are coherent optical receive circuits and said spare optical receive circuit (SRC) is tunable and tuned by a second control signal (CA) produced by said fault evaluating means to select out of said combination of input signals (I1/In) said input signal (Ii) applied to the input of said defective optical receive circuit.

Claim 12

Protection arrangement (Figs 8, 9) according to claim 9, in which said switching means (S) include : - n 1-to-2 switches (S21/S2n) with first and second outputs, the first outputs being connected to respective inputs of said optical receive circuits (RX1/RXn); and - optical coupling means (CM) to couple the second outputs of said n 2-to-1 switches (S21/S2n) to the input of said spare optical receive circuit, said n 1-to-2 switches (S21/S2n) being controlled by said control signal (C) in such a way that they switch to said second output if the receive circuit (RXi) connected to said first output is defective.

Claim 13

Protection arrangement (Figs 7, 8) according to claim 9, in which said fault evaluating means (FE) include: - n test circuits (OBC1/OBCn) which are each part of a respective one of said optical receive circuits (RX1/RXn) to test the working thereof and to provide the corresponding test result signal (C1/Cn) on their output; and - an interpretation module (IM) having n inputs connected to the outputs of said test circuits (OBC1/OBCn) and an output on which said control signal (C) is provided.

Claim 14

Protection arrangement according to claim 9, in which said fault evaluating means (FE) are constituted by a fault evaluating circuit which has n inputs/outputs connected to respective ones of said optical receive circuits (RX1/RXn) and is able to test the working thereof said fault evaluating circuit having an output at which said control signal (C) is provided.