OPTICAL TRANSMISSION APPARATUS

• US 20120183291A1
• Filed: 12/06/2011
• Published: 07/19/2012
• Est. Priority Date: 01/18/2011
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: TOCHIO, Yuji
• Granted Patent: US 9,048,966 B2
• Time in Patent Office: Days
• US Class Current: 398/45
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062

Abstract

An HO ODU signal input to an optical transmission apparatus is disassembled into LO ODUs. LO ODUs specified to form an aggregated ODU are disassembled not into individual LO ODUs but into a unit of an LO ODU group that forms an aggregated ODU. Clock extraction and an alarm process are performed not for the individual LO ODUs but for each aggregated ODU. This eliminates the need for a hardware configuration for performing the clock extraction and the alarm process in units of LO ODUs, leading to saving of hardware resources.

Claims

1. An optical transmission apparatus in a network for making a one-to-multi communication by establishing paths from one point to multi points, comprising:

a reception side high-order layer data unit processing unit configured to demultiplex, as one aggregation, a plurality of data units of a low-order layer transmitted by using a path sharing a section from other data units of a low-order layer when data is transmitted in the section shared by the paths within the network in a process for extracting data units of a low-order layer from a data unit of a high-order layer of an input optical signal;

a reception side low-order layer data unit processing unit configured to perform clock extraction in a unit of the plurality of data units of the low-order layer as one aggregation for the plurality of data units of the low-order layer as one aggregation, and to execute an alarm process in the unit of the plurality of data units of the low-order layer as one aggregation;

a switching unit configured to perform switching by disassembling an output of the reception side low-order layer data unit processing unit into internal frames for switching, and to generate data units of a low-order layer from the internal frames for switching after the switching is performed;

a transmission side low-order layer data unit processing unit configured to insert alarm information, obtained by the reception side low-order layer data unit processing unit, in the plurality of data units of the low-order layer as one aggregation transmitted by using the path sharing the section among the data units of the low-order layer formed after the switching is performed; and

a transmission side high-order layer data unit processing unit configured to assemble the data units of the low-order layer from the transmission side low-order layer data unit processing unit into a data unit of a high-order layer, and to transmit the assembled data unit.

2. The optical transmission apparatus according to claim 1, wherein

the reception side low-order layer data unit processing unit extracts overhead information from the plurality of data units of the low-order layer as one aggregation, and the transmission side low-order layer data unit processing unit mounts the extracted overhead information in the plurality of data units of the low-order layer as one aggregation.

3. The optical transmission apparatus according to claim 1 wherein

an upstream side of an optical transmission apparatus connected to the network transmits a notification signal for notifying information of a path to be formed to the optical transmission apparatus connected to the network, and

each of the optical transmission apparatuses sets a plurality of data units of a low-order layer as one aggregation to data units of a low-order layer which use the path selected from the paths of the network based on the information stored in the notification signal.

4. The optical transmission apparatus according to claim 3, wherein

the path to be formed is automatically formed according to an entire bandwidth possessed by a line, a bandwidth of a link in the network, and a relationship between end points by executing an algorithm.

5. The optical transmission apparatus according to claim 4, further comprising:

a notification unit configured to decide an arrangement within a data unit of a higher-order layer than data units in a unit of switching based on the information of the path to be formed, and to notify an adjacent link of the decided arrangement;

a reception unit configured to receive the arrangement of the data units in the unit of switching from the adjacent link; and

a switch processing unit configured to instruct how to execute a switch process based on the arrangement of the data units in the unit of switching.

6. A controlling method for an optical transmission apparatus in a network for making a one-to-multi communication by establishing paths from one point to multi points, the optical transmission apparatus conducting the method comprising:

demultiplexing, as one aggregation, a plurality of data units of a low-order layer transmitted by using a path sharing a section from other data units of a low-order layer when data is transmitted in the section shared by the paths within the network in a process for extracting data units of a low-order layer from a data unit of a high-order layer of an input optical signal,

performing clock extraction in a unit of the plurality of data units of the low-order layer as one aggregation for the plurality of data units of the low-order layer as one aggregation,

executing an alarm process in the unit of the plurality of data units of the low-order layer as one aggregation,

performing switching by disassembling the data units of the low-order layer into internal frames for switching,

generating data units of a low-order layer from the internal frames for switching after the switching is performed,

inserting alarm information, obtained with the alarm process, in the plurality of data units of the low-order layer as one aggregation transmitted by using the path sharing the section among the data units of the low-order layer formed after the switching is performed, and

assembling the data units of the low-order layer after the switching is performed into a data unit of a high-order layer, and transmits the assembled data unit.