Patent Application
20050013256
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-196635, filed Jul. 14, 2003, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an apparatus and method for generating a synchronous multiplexing frame for testing equipment or the like for use in a synchronous transmission system such as an SDH (Synchronous Digital Hierarchy) scheme or a SONET (Synchronous Optical Network). More particularly, the present invention relates to an apparatus and method for generating a synchronous multiplexing frame which employs a technique capable of setting a frame structure of each channel containing data to be inserted into a payload portion, including TUG3/STS3 and TUG2/VTG channels.
2. Description of the Related Art
In synchronous transmission systems, such as SDH or an SONET, multiplexing processing for generating high speed frame data by multiplexing low speed frame data by a plurality of channels is repeated by a predetermined number of stages, thereby generating synchronous multiplexing frame data at a predetermined transmission speed, and the data generated is transmitted to a transmission channel.
Equipment for use in such a synchronous transmission system is constructed to extract data for a desired channel from inputted synchronous multiplexing frame data and carry out a variety of processing operations.
Therefore, in order to carrying out testing of the equipment for use in the synchronous transmission system, there is a need for a synchronous multiplexing frame generating apparatus for generating frame data having measurement data inserted into a predetermined channel of a payload portion.
This synchronous multiplexing data has a predetermined multiplexing structure. For example, in non-patent document ITU-T G. 707, a multiplexing structure of the SDH scheme is defined as shown in
In this multiplexing structure of the SDH scheme shown in
In
Also, in
That is, in this case, first, in step S1, a container C11 for containing low speed frame data such as primary group information (1.544 Mb/s) is prepared as shown in
Next, in step S2, a low order virtual container VC11 is generated by adding a POH (path overhead) composed of address information such as a transmission source or destination relevant to information on the container C11.
Then, in step S3, a TU (Tributary Unit) pointer is added to the virtual container VC11 to generate TU11 data.
Subsequently, in step S4, TUG (Tributary Unit Group) 2 data is generated by collecting the TU data by 4 channels.
As shown in
Then, in step S5, TUG3 data is generated by collecting the TUG2 data by 7 channels.
Then, in step S6, a high order virtual container VC4 is generated by adding a POH obtained by collecting the TUG3 data by 3 channels.
Next, in step S7, one set of AU4 data is generated by adding an AU (Administrative Unit) pointer to this virtual container VC4.
Subsequently, in step S8, AUG (Administrative Unit Group) 1 data composed of such one set of AU4 data is generated.
Then, in step S9, a frame of STM-1 is completed by adding an SOH (section overhead) to this AUG1.
Further, another multiplexing structure for generating STM-1 is such that, first, processing goes from the step S4 to step S11 in which a high order virtual container VC3 is generated by adding the POH to data obtained by connecting the TUG2 data generated in the step S4 by 7 channels.
Then, in step S12, AU3 data is generated by adding the AU pointer to this high order virtual container VC3.
In addition, in the step S8, AUG1 data is generated by collecting this AU3 data by 3 channels.
Next, in the step S9, a frame of STM-1 is completed by adding the SOH to this AUG1 data.
In the synchronous multiplexing frame generating apparatus for generating a synchronous multiplexing frame used for testing equipment for the above described synchronous transmission system, there is a need for carrying out multiplexing processing as described above to generate synchronous multiplexing frame data having a desired speed.
Conventionally, as such a synchronous multiplexing frame generating apparatus, there is proposed a technique capable of arbitrarily setting frame structure with respect to 3 channels of TUG3 data of an STM-N frame in the SDH scheme, the technique commonly using each frame structure for 7-channel TUG2 data.
Hence, in such a conventional technique, each frame structure of the 7-channel TUG2 data is commonly used, thus making it impossible to easily grasp what structure is produced by the frame structure of each channel of the TUG2. In addition, there is an inconvenience that the operation and testing cannot be carried out for equipment for a synchronous transmission system with a frame structure which is different from another with respect to each channel of the TUG2.
This problem also occurs in frame generation of the SONET scheme defined in Telcordia Technologies or the like. In the SONET, the STS (Synchronous Transport Signal) 3 and the VTG (Virtual Transport Group) correspond to the TUG3 and the TUG2 in the STM-1 frame of the SDH scheme.
It is an object of the present invention to provide a synchronous frame generating apparatus and method, for testing equipment for a synchronous transmission system, the apparatus and method being capable of arbitrarily setting a frame structure of each channel of data to be inserted into a payload portion in a synchronous multiplexing frame of an SDH (Synchronous Digital Hierarchy) scheme or an SONET (Synchronous Optical Network) scheme, including TUG3/STS3 and TUG2/VTG channels.
It is another object of the present invention to provide a synchronous multiplexing frame generating apparatus and method, for testing equipment for a synchronous transmission system, the apparatus and method being capable of: arbitrarily setting a frame structure of each channel of data to be inserted into a payload portion in a synchronous multiplexing frame of an SDH (Synchronous Digital Hierarchy) scheme or an SONET (Synchronous Optical Network) scheme, including TUG3/STS3 and TUG2/VTG channels; and easily identifying a channel for use in measurement.
According to a first aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus for generating a synchronous multiplexing frame in an SDH (Synchronous Digital Hierarchy) scheme or a SONET (Synchronous Optical Network) scheme, for testing equipment for a synchronous transmission system, the apparatus comprising:
According to a second aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the first aspect, wherein the synchronous multiplexing frame is provided as an STM (Synchronous Transport Mode) frame of the SDH scheme or an STS (Synchronous Transport Signal) frame of the SONET scheme,
According to a third aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the first aspect, wherein
According to a fourth aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the second aspect, wherein
According to a fifth aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the fourth aspect, wherein the low order virtual container generating portion (22) is constructed to, in accordance with a frame structure set by the payload structure setting portion (40) in the case of generating a low order virtual container (VC11, VC12, VC2) in the STM frame of the SDH scheme, generate low order virtual containers VC1 and VC2 based on a container C1 (composed of a container C11 of 1.544 Mb/s and a container C12 of 2.048 Mb/s) having contained therein low speed frame data and a container C2 (6.312 Mb/s) and output these VC1 (VC11, VC12, VC2) and VC2 to each of the TUG2 data generating portions 23(1, 1) to 23(3, 7).
According to a sixth aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the fifth aspect, wherein each of the TUG2 data generating portions 23(1, 1) to 23(3, 7) is constructed to provide, by 3×7 channels, while collecting, by 3 channels, TUG3 data (TUG3(1)-TUG3(3)) obtained by collecting 7 channels (TUG2(1, 1)-TUG2(1, 7), TUG2(2, 1)-TUG2(2, 7), TUG2(3, 1)-TUG2(3, 7)) of TUG2 by means of the operating portion (35) via the payload structure setting portion (40) for the purpose of preparation for a case in which there has been specified a frame structure for generating a high order virtual container VC4, and to generate TUG2 data for the 3×7 channel upon the receipt of the low order virtual container by multiplexing TU1 data only after generating TU1 and TU2 data by adding a TU pointer.
According to a seventh aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the sixth aspect, wherein, in the case where there has been specified a frame structure for generating a high order virtual container VC4 while collecting, by 3 channels, TUG3 data obtained by collecting n channels of TUG2 by means of the operating portion (35) via the payload structure setting portion (40), TUG2 data for 3×7 channels generated by the TUG2 data generating portions 23(1, 1) to 23(3, 7) are inputted to the TUG3 data generating portions 24(1) to 24(3) by 7 channels, the inputted data is collected as TUG3(1) to TUG3(3) data for 3 channels, and the collected data is outputted to the frame generating portion (30).
According to an eighth aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the sixth aspect, wherein, in the case where there has been specified a frame structure using a virtual container VC3 which is added a POH (Path Overhead) to a container C3 (44.736 Mb/s or 34.368 Mb/s) for any one of 3 channels of TUG3 by means of the operating portion (35) via the payload structure setting portion (40), a TUG3 data generating portion corresponding to a channel specified in the TUG3 data generating portions 24(1) to 24(3) of the 3 channels is constructed to output to the frame generating portion (30) the TUG3 data from the TUG3 data generating portion (24) as the TUG3 data by generating TU3 data to add a TU pointer to a low order virtual container VC3 generated by the low order virtual container generating portion (22) without using the TUG2 data.
According to a ninth aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the seventh aspect, wherein
According to a tenth aspect of the present invention, there is provided a synchronous multiplexing frame generating apparatus according to the ninth aspect, wherein the header adding portion (32) N-multiplexes same AUG1 data in the case where the N is equal to or greater than 4.
According to an eleventh aspect of the present invention, there is provided a synchronous multiplexing frame generating method for generating a synchronous multiplexing frame in an SDH (Synchronous Digital Hierarchy) scheme or an SONET (Synchronous Optical Network) scheme, for testing equipment for a synchronous transmission system, the method comprising:
According to a twelfth aspect of the present invention, there is provided a synchronous multiplexing frame generating method according to the eleventh aspect, wherein
According to a thirteenth aspect of the present invention, there is provided a synchronous multiplexing frame generating method according to the eleventh aspect, further comprising:
According to a fourteenth aspect of the present invention, there is provided a synchronous multiplexing frame generating method according to the eleventh aspect, further comprising:
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the present invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the present invention.
Reference will now be made in detail to the presently preferred embodiments of the invention as illustrated in the accompanying drawings, in which like reference numerals designate like or corresponding parts.
Hereinafter, one embodiment of a synchronous multiplexing frame generating apparatus according to the present invention will be described with reference to the accompanying drawings.
The synchronous multiplexing frame generating apparatus 20 is provided as a synchronous multiplexing frame generating apparatus for generating a synchronous multiplexing frame in an SDH (Synchronous Digital Hierarchy) scheme or an SONET (Synchronous optical Network) scheme, for testing equipment for a synchronous transmission system. This apparatus comprises a payload data generating portion 21, an operating portion 35, a display 36, a payload structure setting portion 40, and a frame generating portion 30. The payload data generating portion 21 generates payload data to be inserted into a frame structure for each of TUG3/STS3 and TUG2/VTG channels in a payload portion of the synchronous multiplexing frame. The operating portion 35 is capable of arbitrarily setting a frame structure of each channel of payload data to be inserted into the payload portion, including TUG3/STS3 and TUG2/VTG channels, as an operation required for generating a desired synchronous multiplexing frame. The display 36 displays a process of generating the desired synchronous multiplexing frame. The payload structure setting portion 40 is for setting: a frame structure of each channel of payload data to be inserted into the payload portion in a desired structure according to arbitrary setting of the operating portion 35, including the TUG3/STS3 and TUG2/VTG channels; and a frame structure of each channel including payload data generated by the payload data generating portion 21 in a desired structure, including the TUG3/STS3 and TUG2/VTG channels, and further lists and displays the frame structure of each channel including payload data generated by the payload data generating portion 21, the frame structure being set to the desired structure, in a desired mode on the display 36, including the TUG3/STS3 and TUG2/VTG channels. The frame generating portion 30 multiplexes the payload data generated by the payload data generating portion 21 and inserts the multiplexed payload data into the payload portion, and adds a header portion to the payload portion to generate the desired synchronous multiplexing frame and output the frame to a measurement target.
This synchronous multiplexing frame generating apparatus 20 is characterized by being constructed to generate frame data in the SDH (or SONET) scheme and capable of using, for a measurement channel, a frame structure including a TUG2/VTG channel, for example, TUG2 in the SDH scheme, of the channels including data for the payload portion of that frame data.
That is, the synchronous multiplexing frame generating apparatus 20, as shown in
The payload data generating portion 21 generates payload data targeted to be inserted into the payload portion of, for example, frame STM-N (N=1, 4, 16, 64, 256) in the SDH scheme in accordance with a frame structure of each channel set by the operating portion 35 via the payload structure setting portion 40.
The payload data generating portion 21 has a low order virtual container generating portion 22; TUG2 data generating portions 23(1, 1) to 23(3, 7) of a 3×7 channel structure; and TUG3 data generating portions 24(1) to 24(3) of a 3-channel structure.
Here, in the frame structure set by the payload structure setting portion 40, the low order virtual container generating portion 22 is constructed to generate low order virtual containers VC1 and VC2 on the basis of a container C1 (composed of a container C11 of 1.544 Mb/s and a container C12 of 2.048 Mb/s), each of which contains low speed frame data and a container C2 (6.312 Mb/s), and to output these VC1 and VC2 to each of the TUG2 data generating portions 23(1, 1) to 23(3, 7).
Each of the TUG2 data generating portions 23(1, 1) to 23(3, 7) is provided by 3×7 channels, for the purpose of preparation for the case where there has been specified a frame structure for generating a high order virtual container VC4 by collecting, by 3 channels, TUG3 data obtained by collecting 7 channels, of TUG2 by means of the operating portion 35 via the payload structure setting portion 40. These generating portions each are constructed to generate TUG2 data upon the receipt of a low order virtual container.
As has been described above, in the case where there has been specified a frame structure for generating the high order virtual container VC4 by collecting, by 3 channels, TUG3 data obtained by collecting 7 channels, of TUG2 by means of the operating portion 35 via the payload structure setting portion 40, a first 7 channels generated by the TUG3 data generating portions 23(1, 1) to 23(1, 7), TUG2 data for 7 channels, are inputted to the TUG3 data generating portion 24(1), and the inputted TUG2 data are outputted collectively as TUG3(1) data for a first channel.
In addition, a second generated by the TUG2 data generating portions 23(2, 1) to 23(2, 7), TUG2 data for 7 channels, are inputted to the TUG3 data generating portion 24(2), and the inputted TUG2 data are outputted collectively as TUG3(2) data for a second channel.
Further, a third generated by the TUG2 data generating portions 23(3, 1) to 23(3, 7), TUG2 data for 7 channels, are inputted to the TUG3 data generating portion 24(3), and the inputted TUG2 data are outputted collectively as TUG3(3) data for a third channel.
Moreover, in the case where a frame structure using a virtual container VC3 which is added a POH (Path Overhead) to a container C3 (44.736 Mb/s or 34.368 Mb/s) has been specified for any one of three channels, of TUG3, a TUG3 data generating portion 24 corresponding to that channel is constructed to output TUG3 data set in advance in the TUG3 data generating portion 24 without using TUG2 data.
These 3-channel data TUG3(1) to TUG3(3) are inputted to an AU data generating portion 31 of the frame generating portion 30.
The AU data generating portion 31 is constructed to generate a virtual container VC4 by adding a POH (path overhead) to a collection of 3-channel data TUG3(1) to TUG3(3); and to generate 1 set of AU4 data by adding an AU pointer indicating a storage position of a frame to the virtual container VC4 so as to output the generated data to a header adding portion 32 in the frame generating portion 30.
The header adding portion 32 is constructed to complete a frame of a desired STM-N frame set by means of the operating portion 35 via the payload structure setting portion 40 by adding an SOH (section overhead) to AUG1 data composed of such one set of AU4 data, or alternatively, AUG-N data obtained by collecting the AUG1 data by a plurality of channels; and to output the completed frame to a measurement target, although not shown, at a bit rate determined by N (N denotes 1, 4, 16, 64, or 256).
In the case where N is equal to or greater than 4, the header adding portion 32 N-multiplexes the same AUG1 data.
The foregoing is provided as an example in the case where a desired frame structure via AU4 is generated. However, even in the case of a frame structure via AU3, a desired frame structure can be generated similarly.
In this case, the above-described AU4, VC4 and TUG3 are replaced with “AU3” and “VC3”, and N of a frame of STM-N completed at this time is any one of 0, 1, 4, 16, 64, and 256.
On the other hand, the payload structure setting portion 40 is constructed to cause the display 36 to list and display a frame structure of each channel which includes a channel of TUG3 or less, of the payload data generated by the payload generating portion 21, and to set arbitrarily the frame structure of each channel by an operation of the operating portion 35.
Hereinafter, an operation of the synchronous multiplexing frame generating apparatus 20 according to the present embodiment will be described with reference to the flow chart.
First, when a payload structure setting mode is specified by an operation of the operating portion 40, for example, a bit rate setting screen as shown in
On this bit rate setting screen, a current bit rate value (9.95 G) displayed in a bit rate display field can be set to be changed at a predetermined bit rate by an operation of the operating portion 35. In addition, it is possible to select whether to output electrical frame data or optical frame data.
When this bit rate setting process terminates, for example, a main frame setting screen for setting a main frame structure for use in measurement is displayed on the display 36, as shown in
On this main frame setting screen, a current main frame (STM-64-AUG-AU4-TUG3-TUG2-TU2-VC2-6M: wherein 6M corresponds to the container C2) displayed in that display field can be set to be changed into a desired frame structure within the range of bit rates set in the step S21.
When this main frame setting process terminates, for example, a measurement channel setting screen for specifying a main channel for use in measurement in the main frame structure is displayed on the display 36, as shown in
In the current main frame structure (STM-64-AUG-AU4-TUG3-TUG2-TU2-VC2-6M) displayed in that display field, this measurement channel can be arbitrarily specified with respect to an AUG channel (set to 1 as a current value), a TUG3 channel (a current value is 2), and a TUG2 channel ((a current value is 3), by an operation of the operating portion 35.
When specification the measurement channel terminates, for example, a channel structure screen is displayed on the display 36, as shown in
On this channel structure screen, in addition to the previously described main frame structure (STM-64-AUG-AU4-TUG3-TUG2-TU2-VC2-6M), a list of frame structures each corresponding to a combination of TUG3 channels #1, #2 and #3 and TUG2 channels #1, #2, #3, #4, #5, #6 and #7 (in this case, TU11 is set excluding a measurement channel) is displayed in a table format. In addition, a position of a measurement channel specified by processing for specifying the measurement channel, of these combinations, is displayed (as characters “MEAS” representing “measurement” in an example of
Although not shown in the flow chart of
Further, on this channel structure screen, when an edit button indicated by “Edit” is selectively operated by the operating portion 35, for example, an edit screen for changing a frame structure of a non-measurement channel (background) other than the measurement channel, is displayed on the display 36, as shown in
On this edit screen, a display “Bulk” indicating that predetermined data specified in advance corresponding to a frame structure is made on a frame structure display portion for each non-measurement channel (background) other than the measurement channel.
That is, a current display on this edit screen indicates a case in which the TUG3 channel #1 is specified including TUG2 channels #1 (TU11-VC11), #2 (TU11-VC11), #3 (TU11-VC11), #4 (TU11-VC11), #5 (TU11-VC11), #6 (TU11-VC11), and #7 (TU11-VC11); the TUG3 channel #2 is specified including TUG2 channels #1 (TU11-VC11), #2 (TU11-VC11), #3 (TU2-VC2, here, #3 denotes a measurement channel), #4 (TU11-VC11), #5 (TU11-VC11), #6 (TU11-VC11), and #7 (TU11-VC11); and the TUG3 channel #3 is specified including TUG2 channels #1 (TU11-VC11), #2 (TU11-VC11), #3 (TU11-VC11), #4 (TU11-VC11), #5 (TU11-VC11), #6 (TU11-VC11), and #7 (TU11-VC11).
A frame structure of each channel other than the measurement channels can be set to be arbitrarily changed as shown in
That is, the edit screen displayed after this change indicates a case in which the TUG3 channel #1 is specified including TUG2 channels #1 (TU11-VC11), #2 (TU11-VC11), #3 (TU11-VC11), #4 (TU11-VC11), #5 (TU11-VC11), #6 (TU11-VC11), #7 (TU11-VC11); and the TUG2 channel #2 is specified including TUG2 channels #1 (TU11-VC11), #2 (TU11-VC11), #3 (TU2-VC2, here, #3 denotes a measurement channel), #4 (TU12-VC12), #5 (TU11-VC11), #6 (TU12-VC12), and #7 (TU2-VC2), and further including the TUG3 channel #3 and a TU3-VC3.
When processing for changing a frame structure of each channel other than the measurement channels terminates, the edit screen is cleared (steps S30 and S31), and the channel structure screen shown in
However, at this time, a frame structure for each channel other than the measurement channel is changed by reflecting the previously described edit result, as shown in
That is, on this channel structure screen after the edit, in addition to the previously described main frame structure (STM-64-AUG-AU4-TUG3-TUG2-TU2-VC2-6M), a list of frame structures is displayed in a table format, each of which corresponds to a combination of the TUG3 channel #1 and its, TUG2 channel #1 (TU11), #2 (TU2), #3 (TU12), #4 (TU12*), #5 (TU11), #6 (TU2), #7 (TU12); and the TUG3 channel #2 and its TUG2 channels #1 (TU12*), #2 (TU11), #3 (measurement channel: MEAS), #4 (TU12), #5 (TU11), #6 (TU12), #7 (TU12); and the TUG3 channel #3 and its TU3-VC3.
In this manner, after a frame structure for each channel has been set, the payload generating portion 21 generates each item of payload data targeted to be inserted into a payload portion and outputs the generated payload data to the frame generating portion 30 in accordance with the content finally displayed on the channel structure screen.
Then, from the frame generating portion 30, the frame data obtained by inserting into the payload portion the data for each channel multiplexed in the frame structure displayed on the channel structure screen is delivered to a measurement target at a specified bit rate.
Data required for measurement in the payload generating portion 21 is inserted into a measurement channel of this frame data. By providing this frame data to equipment targeted for measurement, testing of an operation for data with different frame structures of each channel can be carried out.
In addition, in the flow chart of
In this manner, the synchronous multiplexing frame generating apparatus 20 according to the present embodiment is constructed to list and display a frame structure of each channel including a TUG2 channel in which the payload data generated by the payload generating portion 21 is included on the screen of the display 36, and arbitrarily change and set such a frame structure.
Thus, the frame structure of each channel including a TUG2 channel can be easily understood, operation and testing of equipment for a frame of the SDH scheme which is different in frame structure of each channel can be carried out, and more practical testing can be performed.
Moreover, a position of a measurement channel can be displayed to be identifiable from another channel in such listing display. Thus, a TUG2 measurement channel can be clearly understood, and a channel can be precisely specified for equipment for a synchronous transmission system targeted for measurement.
In the present embodiment, a description has been given with respect to a case of generating a frame of the SDH scheme. However, the present invention can be applied similarly to a case of generating a frame of the SONET scheme equivalent to that of the SDH frame.
In this case, for example, the TUG3, TUG2, and AU pointer in the case of generating the STM-N frame of the SDH scheme described above may be replaced with “STS3”, “VTG”, and “STS pointer” in the case of generating the STS frame of the SONET scheme, respectively.
As has been described above, the synchronous multiplexing frame generating apparatus according to the present invention is constructed to list and display on a display screen a frame structure of each channel including payload data generated by a payload generating portion, and arbitrarily change and set such a frame structure including TUG3 and TUG2 channels.
In this way, the frame structure of each channel including TUG3 and TUG2 channels can be easily understood, and operation and testing of equipment for a synchronous transmission system targeted for measurement with respect to a synchronous multiplexing frame which has different frame structures for each channel, including TUG3 and TUG2 channels, can be carried out, thus more practical testing can be performed.
In addition, the position of a measurement channel in such listing display is displayed to be identifiable from another channel. Thus, a TUG2 measurement channel can be clearly grasped, and a channel can be precisely specified for equipment for a synchronous transmission system targeted for measurement.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-196635 | Jul 2003 | JP | national |
