JP3368454B2 - Cell loss / misplacement detection processing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell loss / mis-delivery detection processing method for detecting loss or mis-delivery of a user cell using a performance management cell. ATM (Asynchronous transfer mode; A
In the synchronous transfer mode) network, a 53-byte cell consisting of a 5-byte header and a 48-byte payload is used, and data between users is inserted into this payload for transmission. For network performance management, OAM (maintenance operation; Operation, Administration and Maintenance)
e) A cell is transmitted, and a performance management cell is one of the OAM cells. This performance management cell is transmitted and received between the terminal stations, and detects loss or misdelivery of user cells based on the number of transmitted user cells and the number of received user cells. It is desired to make the structure for detecting cell loss and cell misdelivery in such performance management economical.

[0002]

2. Description of the Related Art FIG. 9 is a schematic explanatory view of a transmission system and a transmission format, 11 and 12 are terminal devices, and 13-
1 to 13-n are exchanges (switches) that form a transmission network. In this transmission network, a performance management cell in the forward direction is sent out for performance management, and a performance management cell in the reverse direction is sent out. For example, in the exchange 13-1, a forward direction performance management cell (FM cell; Forward M)
onitoring Cell), the number of user cells sent is about 25
6, 512, 1024, etc. are inserted and sent out every predetermined number. The exchange 13-1 and the exchange 13-n forming a segment of the transmission network detect this FM cell and detect this FM cell.
Reverse performance management cell based on cell (BM cell; Backwar
d Reporting Cell).

Payload of this FM cell and BM cell
(48 bytes) format is 4 bit OA
M-cell type OAMTP and 4-bit funky
Type FTP and 8-bit management cell sequence
Transmission of the user cell of 16-bit configuration and the mobile number MCSN
Count value TUC_{0 + 1}And 16-bit block error
Detection code BEDC_{0 + 1}And 16-bit cell loss
Transmission amount of user cells whose priority indication bit CLP is "0"
Numerical value TUC₀And a 32-bit time stamp TS
TP, unused bit area UNU, and 16-bit configuration
Cell loss priority bit CLP of "0" received cell
Count value of TRCC₀And block error of 8 bit configuration
Result BLER_{0 + 1}And counting received cells with 16 bits
Value TRCC _{0 + 1}And the reserved bit area Res and 10
It includes an error detection code EDC having a bit structure.
It

The aforementioned subscript 0 indicates that the cell loss priority indication bit CLP is "0", and 0 + 1.
Indicates that the cell loss priority indicator bit CLP relates to cells of "0" and "1". OAM cell type OAM
Cell identification is performed by setting the TP as "0010", the FM cell function type FTP as "0000", and the BM cell function type FTP as "0001". Also, the FM cells transmitted in the forward direction are TRCC ₀ , B.
The areas of LER _{0 + 1} and TRCC _{0 + 1} are not used. The BM cell transmitting in the reverse direction does not use the area of BEDC _{0 + 1} .

In the exchange 13-1, the user cell having the cell loss priority indicator bit CLP of "0" is counted, and also the user cells of "0" and "1" are counted, and when the predetermined value is reached. , The next FM cell is transmitted, the transmission count value of the user cell of CLP = "0" at that time is set to TUC ₀ , and the transmission count value of the user cell of CLP = "1" and "0" is set. It is inserted into TUC _{0 + 1} and transmitted.

In addition, in the exchange 13-n, the number of received user cells is counted for the user cells whose cell loss priority indicator bit CLP is "0" and for the user cells "0" and "1". Also, each count value and the transmission count value TU of the user cell of the received FM cell are counted.
It compares C ₀ and TUC _{0 + 1} to identify whether the user cell has been lost or mis-distributed.

In the exchange 13-n, as described above, the result of counting the number of receiving user cells is inserted into the count values TRCC ₀ , TRCC _{0 + 1} of the receiving cells of the BM cell and transmitted. . The exchange 13-1 receives the BM cell and compares the count values TRCC ₀ and TRCC _{0 + 1} with the transmission count values TUC ₀ and TUC _{0 + 1} inserted in the FM cell to determine the user cell. Can be identified as lost or mis-delivered. That is, if the number of sending user cells and the number of receiving user cells between FM cells are the same, it is determined as normal reception, and if the number of receiving user cells is less than the number of transmitting user cells, it is determined as cell loss, If the number of cells is less than the number of received user cells, it is determined that the cells are mis-distributed.

FIG. 10 is an explanatory view of a main part of a cell loss / misdistribution detection unit of a conventional example. Reference numeral 21 is a user cell detection unit, 22 is a performance management cell detection unit, 23 is a memory, and 23a is a TRCC addition memory unit. , 23b are memory portions for holding TRCC, 23b
c is a memory unit for holding TUC, 24 is an access control unit, 2
Reference numeral 5 is a TRCC adder, 26 is a cell loss / misallocation calculation processing unit, and 27 is a cell transmission path, which is a main part in an exchange that receives FM cells and sends out BM cells.

The memory 23 has an area corresponding to VP / VC, and when the loss / misdelivery of the user cell is detected by the FM cell detection, the transmission count value TUC of the previously detected FM cell is detected.
Memory unit 23c for holding the TUC and the previous FM
TR that holds the reception count value TRCC when the cell is detected
The memory unit 23b for CC holding and the memory unit 23a for adding TRCC, which is the content of the reception count value TRCC when the FM cell of this time is detected, are used to detect loss / misdelivery of a user cell by BR cell detection. In this case, the TUC holding memory unit 23c for holding the transmission count value TUC of the BR cell detected last time and the reception count value T of the BR cell detected last time
It is composed of a TRCC holding memory unit 23b that holds an RCC.

Further, the user cell detection unit 21 or the performance management cell detection unit 22 outputs V based on the header information of the received user cell.
The P / VC is identified, and the access control unit 24 generates the access address of the memory 23 according to the identification result. Also, the TRCC adding unit 25 obtains the reception count value TRCC by incrementing the content of the TRCC addition memory unit 23a by +1 for each VP / VC every time the user cell detection unit 21 detects a reception user cell.

When the performance management cell detection unit 22 detects an FM cell, the cell loss / misallocation calculation processing unit 26 detects the transmission count value TUC of the user cell of the payload of this FM cell.
And the difference between the previous transmission count value stored in the TUC holding memory unit 23c and the present FM cell.
The number of transmitted user cells until the reception of M cells is calculated. Also, the previous reception count value stored in the TRCC holding memory unit 23b and the TRCC addition memory unit 2 at that time
The difference from the count value of the content of 3a is obtained, and the number of received user cells from the previous FM cell to the reception of this FM cell is obtained. Then, the number of transmitted user cells and the number of received cells are compared, and if the number of transmitted cells and the number of received cells are the same,
It can be determined that there is no loss and misdelivery of user cells, and that there is a loss when the number of received cells is smaller than the number of transmitted cells, and there is a misdelivery when the number of received cells is greater than the number of transmitted cells.

FIG. 11 is a flow chart of the cell loss / misdistribution detection process by the FM cell of the conventional example.
UC1 is the transmission count value of the user cell at times t0 and t1 on the FM cell transmission side, and TRCC0 and TRCC1 are F
The reception count value of the user cell at times t0 and t1 on the M cell reception side is shown. In this case, the transmission time t0 of the FM cell,
The number of transmissions during t1 can be obtained from TUC1 to TUC0, and the number of receptions between FM cell reception times t0 and t1 can be obtained from TRCC1 to TRCC0. However, the transmission count value and the reception count value are, for example, 2
^It is necessary to perform the processing described later to count by a ^16- configuration counter.

First, it is determined whether the user cell detection unit 21 detects a user cell (H1). If the user cell is not detected, it is determined whether the performance management cell detection unit 22 detects an FM cell. (H3), or when a user cell is detected, the TRCC addition unit 25 causes TRCC1 = TR
As indicated by CC1 + 1, the contents of the TRCC addition memory unit 23a are incremented by 1 (H2).

In the case of FM cell detection, the cell loss / misdistribution operation processing unit 26 performs the operation shown in step (H4). In addition, the TRCC addition memory unit 2 of the memory 23
3a, the TRCC holding memory unit 23b and the TUC holding memory unit 23c each have a 16-bit configuration. Therefore, by adding +1 to 65535, the value returns to 0. May be a negative number. For example, TUC1 <TUC
It may become 0, and in that case it becomes a negative number, so 2 ¹⁶ which is the maximum value of the count value is added to make it a positive number. Then, the result of adding 2 ¹⁶ to the difference between the count values is 2 ¹⁶
Divide by and use the remainder. That is, [
] ₂ ¹⁶ indicates that the calculation result in [] is divided by 2 ¹⁶ and the remainder is used.

Therefore, [2 ¹⁶ + TUC1-TUC0] ₂
¹⁶ indicates that the remainder of (2 ¹⁶ + TUC1-TUC0) / 2 ¹⁶ is used, and [2 ¹⁶ + TRCC1-TRCC0]
₂ ¹⁶ indicates that the remainder of (2 ¹⁶ + TRCC1−TRCC0) / 2 ¹⁶ is used. Then, it is determined whether or not D = 0 (H5), and if D = 0, it is determined whether or not D ≦ 2 ¹⁵ (H6).

In this case, since D = 0 indicates that the number of transmitted user cells is the same as the number of received user cells, normal reception is determined (H7). If D ≠ 0 and D ≦ 2 ¹⁵ , it is determined to be a cell loss (H8). If D ≠ 0 and D> 2 ¹⁵ is determined to be a cell misdelivery (H9). The criterion for determining the cell loss and the cell misdelivery is not limited to 2 ¹⁵ and can be selected according to the system.

Then, the transmission count value TUC1 by the FM cell this time is set as TUC0 for the next calculation, and the reception count value TRCC1 of the user cell is set as TR for the next calculation.
Set to CC0. That is, TUC0 = TUC1, TRCC0
= TRCC1 to update the TUC holding memory unit 23c of the memory 23 and the TRCC holding memory unit 23.
b is updated.

FIG. 12 is an explanatory diagram of a cell loss / misdistribution detection process by the BR cell of the conventional example, and the side that receives and detects the BR cell is the BR in the performance management cell detection unit 22 of FIG.
A cell is detected, and it is determined whether or not a BR cell is detected (I1). When a BR cell is detected, the same calculation processing as the calculation processing in step (H4) described above is performed for cell loss / cell loss. It will be performed in the mis-allocation calculation processing unit 26 (I
2).

Next, it is judged whether D = 0 (I3), and whether D≤2 ¹⁵ (I4). If D = 0, it is judged that the reception is normal (I5), and D is received. If ≤2 ¹⁵ , it is determined to be cell loss (I6), and if D> 2 ¹⁵ is determined to be cell mis-delivery (I7). And TUC0 = TUC1 and TRCC0
The TUC holding memory unit 23c and the TRCC holding memory unit 23b of the memory 23 are updated so that = TRCC1.

[0020]

In the above-mentioned conventional example, for example, a TRCC addition memory unit 23a and a TRCC holding memory unit 23b each having a 16-bit structure,
It has a memory 23 including a TUC holding memory unit 23c and has a region corresponding to VP / VC. Therefore, the capacity of the memory 23 becomes very large as the number of VP / VCs whose performance is to be monitored increases. There is a growing problem. The present invention is
It is an object of the present invention to provide a cell loss / misplacement detection processing method capable of reducing the capacity of the memory 23.

[0021]

The cell loss / misplacement detection processing method of the present invention is as follows: (1) A forward performance management cell (FM cell) to which a transmission count value of a user cell is added is transmitted, Direction performance management cell is received, and the transmission count value (T
UC) and the reception count value (TRCC) of the user cell to detect a cell loss or a cell misdelivery by comparing the number of transmitted user cells and the number of received user cells during the reception time of the performance management cell. In addition, a performance control cell (BR cell) in the reverse direction in which the transmission count value and the reception count value are added based on the performance management cell in the forward direction is transmitted, and the performance management cell in the reverse direction is received and transmitted. In the cell loss / mis-delivery detection processing method for detecting cell loss and cell mis-delivery based on the count value and the reception count value, when the performance management cell is received this time, the transmission count value and the reception count value are Based on the difference and the difference data between the transmission count value and the reception count value obtained at the time of reception of the previous performance management cell held in the memory, cell loss or misdelivery of the cell is detected,
In addition, the difference data between the transmission count value and the reception count value when the performance management cell is received this time is held in the memory until the next time.

(2) On the reception side of the performance management cell in the forward direction, a memory unit for counting the number of received user cells and difference data between the reception count value and the transmission count value by this memory unit are used for the next performance. Having a holding memory unit that holds until reception of the management cell, using the difference between the transmission count value by the performance management cell and the reception count value by the memory unit, and the difference data read from the holding memory unit, A process of detecting cell loss and cell misdelivery may be included.

(3) The receiving side of the performance management cell in the reverse direction has a holding memory unit for holding difference data between the transmission count value and the reception count value added to the performance management cell, When the performance management cell is received, the cell loss and the cell loss are determined based on the difference between the transmission count value and the reception count value added to the performance management cell and the previous difference data read from the holding memory unit. A process of detecting misdelivery can be included.

(4) When the performance management cell is first received, the difference data held in the holding memory section is initialized by the difference data between the transmission count value and the reception count value when the performance management cell is received. The process can be included.

(5) On the reception side of the performance management cell in the forward direction, the contents of the memory unit for counting the number of received user cells after detecting the cell loss and the cell mis-delivery are set to the performance in the forward direction. A process for updating using the transmission count value added to the management cell, and a performance management cell counter that counts the number of received user cells by generating a performance management cell in the reverse direction based on the performance management cell in the forward direction It is possible to include a process of providing the received count value by the performance management cell counter and transmitting the added count value to the performance management cell.

(6) When the performance management cell is first received, the difference data held in the holding memory unit is initialized by the difference data between the transmission count value and the reception count value when the performance management cell is received. And a step of updating the content of the memory unit that counts the number of received user cells using the transmission count value added to the performance management cell in the forward direction after detecting the cell loss and the cell misdelivery. , A performance management cell in the reverse direction is generated based on the performance management cell in the forward direction, a performance management cell counter for counting the number of received user cells is provided, and a reception count value by the performance management cell counter is
The process of adding to the performance management cell and transmitting it can be included.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an FM of an embodiment of the present invention.
It is a cell loss / mis-delivery detection processing flowchart by a cell, and it is determined whether it is a user cell detection (A1).
3). In the case of user cell detection, TRCC = TRCC
The reception count value of the user cell is incremented by 1 as indicated by +1. In the case of FM cell detection, D = [2 ¹⁶ + [2 ¹⁶ + T
UC-TRCC] ₂ ¹⁶ -REG] ₂ ¹⁶ ] is calculated (A4), and it is determined whether D = 0 (A5). If not 0, it is determined whether D ≦ 2 ¹⁵ (A6). ), D = 0, normal reception (A7), D ≦ 2 ¹⁵ cell loss (A
8), D> in the case of two ¹⁵ determines that cell misinserted (A9), R
EG = [2 ¹⁶ + TUC-TRCC] ₂ ¹⁶ (A1
0).

In the conventional example, the above-mentioned identification value D is D = [2 ¹⁶ + [2 ¹⁶ + TUC1-TUC0] ₂ ^16- [2 ¹⁶ + TRCC1-TR CC0] ₂ ¹⁶ ] ₂ ¹⁶ By modifying this, it is possible to obtain D = [2 ¹⁶ + [2 ¹⁶ + TUC1-TRCC1] ₂ ^16- [2 ¹⁶ + TUC0-TR CC0] ₂ ¹⁶ ] ₂ ¹⁶ . Therefore, [2 ¹⁶ + TUC0-TR
CC0] ₂ ¹⁶ is held as one data REG. That is, the difference data REG between the previous transmission count value TUC0 and the reception count value TRCC0 is held, and the difference between this difference data REG and the difference between the present transmission count value TUC1 and the reception count value TRCC1 is calculated, and the difference is calculated. Is zero,
Even if the last difference data REG is not zero, it can be determined that the reception is normal this time.

FIG. 2 is an explanatory view of the essential parts of the cell loss / mis-distributor detecting section according to the embodiment of the present invention.
Is a performance management cell detection unit, 3 is a memory, 3a is a TRCC addition memory unit, 3b is a REG holding memory unit, 4 is an access control unit, 5 is a TRCC addition unit, 6 is a cell loss / misallocation calculation processing unit, Reference numeral 7 denotes a cell transmission path, which shows a main part of the configuration on the FM cell detection side.

In the case of the cell loss / mis-delivery detection processing by the FM cell, when the user cell is detected by the user cell detection unit 1 as described above, the address corresponding to the VP / VC of the user cell is access-controlled. Access by the unit 4 and the TRCC addition unit 5 by the TRCC addition memory unit 3
The content of a is incremented by 1, and TRCC = TRCC + 1 is set as shown in step (A2).

When the performance management cell detection unit 2 detects an FM cell, the access control unit 4 accesses the address corresponding to the VP / VC of the FM cell, and the previous transmission count value TUC0 from the REG holding memory unit 3b. And data REG = corresponding to the difference between the received count value TRCC0
[2 ¹⁶ + TUC0-TRCC0] ₂ ¹⁶ is read, and in the cell loss / misallocation calculation processing unit 6, the transmission count value TUC1 inserted in the reception FM cell and the TRCC addition memory unit 3 are read.
The difference between the received count value TRCC1 read from a and the data R read from the REG holding memory unit 3b are obtained.
Using EG, as shown in step (A4) of FIG.
D = [2 ¹⁶ + [2 ¹⁶ + TUC1-TRCC1] ₂ ¹⁶ −
[2 ¹⁶ + TUC0-TRCC0] ₂ ¹⁶ ] ₂ ¹⁶ = [2 ¹⁶ +
[2 ¹⁶ + TUC1-TRCC1] ₂ ¹⁶ -REG] ₂ ¹⁶ is calculated.

For the identification value D of this operation result, D = 0
In this case, as described above, the difference between the previous difference data REG and the current difference is zero, which means that the number of transmitted user cells between FM cells is equal to the number of received user cells. To determine. The case of D ≦ 2 ¹⁵ corresponds to the case where the number of received user cells is smaller than the number of transmitted user cells between FM cells, and it is determined that the cell loss has occurred. If D> 2 ¹⁵ , then F
This corresponds to the case where the number of received user cells is larger than the number of transmitted user cells among M cells, and it is determined that the cells are mis-distributed from another VP / VC.

In this case, since the memory 3 can be composed of the TRCC addition memory unit 3a and the REG holding memory unit 3b, assuming that the memory depth of the conventional example is 48 bits, in the present invention. Can be reduced to 32 bits. On the BR cell detection side, the memory 3
Since only the REG holding memory unit 3b is required, if the memory depth of the conventional example is 32 bits, it can be reduced to 16 bits in the present invention.

FIG. 3 is a flow chart of a cell loss / misplacement detection process by a BR cell according to an embodiment of the present invention. It is judged whether or not a BR cell is detected (B1), and the performance management cell detection unit 2
If a BR cell is detected by (see Fig. 2), cell loss
The mis-allocation calculation processing unit 6 is D = [2 ¹⁶ + [2 ¹⁶ + TUC-T
RCC] ₂ ¹⁶ -REG] ₂ ¹⁶ is calculated (B2), and it is further determined whether D = 0 (B3). If D ≠ 0, it is determined whether D ≦ 2 ¹⁵ ( B4), normal reception when D = 0 (B5), cell loss (B6) when D ≦ 2 ¹⁵ ,
If D> 2 ¹⁵ , it is determined that the cell is mis-distributed (B7), and the calculation result of [2 ¹⁶ + TUC-TRCC] ₂ ¹⁶ at this time is set as the difference data REG to the REG holding memory unit 3b.
Hold until R cell reception.

FIG. 4 is a flow chart of a cell loss / misplacement detection process by an FM cell according to another embodiment of the present invention, in which an initial setting step is added, and steps (C1) to (C1) to
(C3) is the same as steps (A1) to (A3) in FIG. 1, but when it is determined that the FM cell is detected in step (C3), the initial flg is determined (C4). When the initial flg is not OFF but is ON, which corresponds to the case where the first FM cell is detected, which indicates an uninitialized state, the REG holding memory unit 3b of the memory 3 (see FIG. 2).
The data REG held in (see) indicates uncertain contents, and if the presence or absence of cell loss or cell misdelivery is determined using this data REG, the possibility of error increases,
At the first FM cell detection, the data REG is initialized without performing the cell loss and cell misdelivery detection processing. That is, the transmission count value TU inserted in the FM cell
Initialization is performed by calculating REG = [2 ¹⁶ + TUC-TRCC] ₂ ¹⁶ corresponding to the difference value between C and the reception count value TRCC at that time, and writing the result in the REG holding memory unit 3b (C5), In addition, the initial flg = OFF.

When the next FM cell is received, the initial fl
Since g = OFF, the operation of step (C6) is performed using the data REG held in the REG holding memory unit 3b, and the steps (A5) to (A1) shown in FIG.
By the same steps (C7) to (C12) as in 0), it is determined whether the reception is normal, the cell is lost, or the cell is misdelivered, and the transmission count value TUC and the reception count value TRCC at that time are determined. The data REG corresponding to the difference is stored in the REG holding memory 3b and used at the next FM cell detection.

FIG. 5 shows a BR cell according to another embodiment of the present invention.
It is a cell loss / mis-delivery detection processing flowchart,
Whether a BR cell is detected by adding a setting step
Whether or not it is determined (D1) and a BR cell is detected, the initial f
It is determined whether lg = OFF (D2). Initial flg =
ON indicates a case where initialization is not performed, and in this case, R
The above-mentioned step (C5) is added to the EG holding memory section 3b.
Similarly, REG = [2 ¹⁶+ TUC-TRCC]₂ ¹⁶Calculate
Initialize by writing and writing (D4).
Set lg = OFF.

Therefore, when the next BR cell is detected, since the initial flg = OFF, D = [2 ¹⁶ + [2 ¹⁶ + TU]
C-TRCC] ₂ ¹⁶ -REG] ₂ ¹⁶ is calculated (D
4) Regarding the identification value D, the steps (C7) to
By the same steps (D5) to (D10) as in (C12), it is determined whether there is normal reception, cell loss, or cell misdelivery,
In addition, the contents of the REG holding memory unit 3b are updated.

FIG. 6 is a flow chart of cell loss / misplacement detection processing by an FM cell according to still another embodiment of the present invention.
It includes a step of receiving and detecting an FM cell and generating a BR cell, and it is judged whether or not a user cell is detected (E
1) If it is not a user cell, it is determined whether an FM cell is detected (E3), and if a user cell is detected, the reception count value TRCC is incremented by 1 (E2).

When an FM cell is detected, the initial flg
= OFF is determined (E4), and when the first FM cell is detected, since the initial flg = ON, the transmission count value TUC by the FM cell and the reception count value T of the user cell at that time are determined.
REG = [2 ¹⁶ + TUC-TRCC] based on RCC
₂ ¹⁶ is calculated and written in the REG holding memory unit 3b,
Also, the reception count value TRCC is made to match the transmission count value TUC (TRCC = TUC) (E5). Also initial flg = OFF
And

When the next FM cell is detected, the initial flg
= OFF, the process moves to step (E6), and D =
[2 ¹⁶ + TUC-TRCC] ₂ ¹⁶ is calculated, and the same step (E) as the above steps (C7) to (C11) is performed.
From 7) to (E11), it is determined whether normal reception, cell loss, or cell misdelivery.

In order to generate the BR cell, the transmission count value TUC at that time is set as the TUC for the BR cell, and TR
By the calculation of CC = [2 ¹⁶ + TRCC-REG] ₂ ¹⁶ ,
The TRCC for the BR cell is calculated (E12). Also next F
REG = [2 ¹⁶ + TUC- for use when detecting M cells
TRCC] ₂ ¹⁶ is calculated, the REG holding memory unit 3b is updated, and TRCC = TUC is set (E13).

FIG. 7 is a flow chart of a cell loss / misplacement detection process by an FM cell according to still another embodiment of the present invention.
A case where a counter for generating a BR cell is provided is shown. It is determined whether or not a user cell is detected (F1). If it is not a user cell, it is determined whether or not an FM cell is detected (F4). , +1 the reception count value TRCC (F2),
The reception count value TRCCB of the user cell by the BR cell generation counter is incremented by 1 (F3).

In the case of FM cell detection, D = [2 ¹⁶ + T
UC-TRCC] ₂ ¹⁶ is calculated (F5), and the identification value D
Regarding the above, by the steps (F6) to (F10) similar to the above steps (E7) to (E11), whether the normal reception is performed,
It is determined whether there is a cell loss or a cell misdelivery. Then, the reception count value TRCC is updated to the transmission count value TUC of the FM cell (F11). When a BR cell is generated based on this FM cell, the reception count value is the TR obtained in step (F3).
CCB is used.

FIG. 8 is a flow chart of a cell loss / misplacement detection process by an FM cell according to still another embodiment of the present invention.
A case where a BR cell generation counter and an initialization step are provided is shown, and it is determined whether or not a user cell is detected (G1). If it is not a user cell, it is determined whether or not an FM cell is detected (G1).
4) In the case of user cell detection, the reception count value TRCC is incremented by 1 (G2), and the reception count value TRCCB of the user cell by the BR cell generation counter is incremented by 1 (G3).

In the case of FM cell detection, initial flg = O
It is determined whether it is FF (G5). In the case of the first FM cell, since the initial state is flg = ON, the transmission count value TUC by the FM cell is initialized as the reception count value TRCC (G6). That is, the contents of the TRCC addition memory unit 3a (see FIG. 2) are updated to TUC so that the count value on the sending side of the FM cell matches the count value on the receiving side of the FM cell.
Then, the initial flg = OFF.

In the case of detection of the next FM cell, the initial flg
== OFF, D = [2 ¹⁶ + TUC-TRCC]
Performs an operation of ₂ ¹⁶ (G7), the identification value D, the same steps as the above-mentioned step (F6) ~ (F10) ( G
8) to (G12), it is determined whether normal reception, cell loss, or wrong cell distribution. Then, the reception count value TRCC
Is updated to the transmission count value TUC of the FM cell (G13).
When a BR cell is generated based on this FM cell, the TRCCB obtained in step (G3) is used as the reception count value.

The present invention is not limited to the above-mentioned embodiments, but can be variously added and changed. For example, the maximum value of the count value is set to 2 ^16. Of course, it is possible. The above-mentioned arithmetic processing and comparison processing for determining normal reception, cell loss, cell misdelivery, etc. can be executed by software, but in the case of high-speed processing, it can be executed by hardware. In that case, it can be configured by a dedicated arithmetic circuit or a processor. It is also possible to select different criteria other than 2 ¹⁵ for the cell loss and cell misdelivery criteria.

[0049]

As described above, the cell loss / misplacement detection processing method of the present invention holds the difference data REG between the transmission count value and the reception count value of the user cell and stores the difference data REG in the next performance management cell (RM). Cell, BR cell), the difference between the transmission count value and the reception count value is calculated, and the difference between the difference and the held difference data REG is calculated to determine whether normal reception, cell loss, or cell misdistribution It is possible to hold the difference data REG with half the capacity as compared with the conventional example that requires a memory for holding the transmission count value and the reception count value. There is an advantage that can be reduced.

Further, when the first performance management cell (FM cell) is received and detected, the difference data REG has an uncertain value, so that the normal reception, the cell loss, and the cell misdelivery determination are stopped, and at that time. Initialization can be performed using the obtained difference data REG. In that case, there is an advantage that erroneous determination of cell loss and erroneous cell distribution can be prevented from the start of communication, and stable performance management can be performed.

Further, when a backward performance management cell (BR cell) is generated based on a forward performance management cell (FM cell) and transmitted, the reception count value of the user cell is updated by the transmission count value. Thus, the count values of the sending side and the receiving side of the user cell can be matched and the counting of the next user cell can be started. At this time, it is possible to provide a counter for the performance management cell in the reverse direction, perform reception counting of the user cell, add the reception count value to the performance management cell in the reverse direction, and send it.

[Brief description of drawings]

FIG. 1 is a cell loss caused by an FM cell according to an embodiment of the present invention.
It is an erroneous distribution detection processing flowchart.

FIG. 2 is an explanatory diagram of a main part of a cell loss / misdistribution detection unit according to an embodiment of the present invention.

FIG. 3 is a cell loss caused by a BR cell according to an embodiment of the present invention.
It is an erroneous distribution detection processing flowchart.

FIG. 4 is a flowchart of a cell loss / misdistribution detection process by an FM cell according to another embodiment of the present invention.

FIG. 5 is a flowchart of a cell loss / misdistribution detection process by a BR cell according to another embodiment of the present invention.

FIG. 6 is a flowchart of a cell loss / misplacement detection process by an FM cell according to still another embodiment of the present invention.

FIG. 7 is a flowchart of a cell loss / misplacement detection process by an FM cell according to still another embodiment of the present invention.

FIG. 8 is a flowchart of cell loss / misplacement detection processing by an FM cell according to still another embodiment of the present invention.

FIG. 9 is a schematic explanatory diagram of a transmission system and a transmission format.

FIG. 10 is an explanatory diagram of a main part of a cell loss / misplacement detection unit of a conventional example.

FIG. 11 is a flowchart of a cell loss / misplacement detection process by the FM cell of the conventional example.

FIG. 12 is a flowchart of a cell loss / misplacement detection process by a BR cell of a conventional example.

[Explanation of symbols]

(A1) to (A10) Steps of detection processing

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidetoshi Ishikawa 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (72) Inventor Hiroshi Ota 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph Telephone Corporation (56) Reference JP-A-8-97820 (JP, A) JP-A-6-311176 (JP, A) JP-A-9-83527 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) H04L 12/56 400

Claims (6)

(57) [Claims] 1. A performance management cell in the forward direction to which a transmission count value of a user cell is added is transmitted, the performance management cell in the forward direction is received, and the transmission count value and the reception count value of the user cell Based on, by comparing the number of transmission of the user cell and the number of reception during the reception time of the performance management cell,
Detecting cell loss or cell mis-delivery, and sending out a performance management cell in the reverse direction to which the transmission count value and the reception count value are added based on the performance management cell in the forward direction, and performing performance management in the reverse direction. In the cell loss / mis-delivery detection processing method of receiving a cell and detecting cell loss and cell mis-delivery based on the transmission count value and the reception count value, when the performance management cell is received this time, The difference between the transmission count value and the reception count value, based on the difference between the difference data between the transmission count value and the reception count value obtained at the time of the previous reception of the performance management cell held in the memory, the cell A cell including a process of detecting loss or misdelivery of a cell and holding difference data between the transmission count value and the reception count value at the time of reception of a performance management cell this time in the memory until the next time. Loss / misdelivery detection processing method. 2. A memory unit that counts the number of receptions of the user cell at the reception side of the performance management cell in the forward direction, and a difference data between the reception count value by the memory unit and the transmission count value A holding memory unit that holds the performance management cell until reception, and uses the difference between the transmission count value of the performance management cell and the reception count value of the memory unit, and the difference data read from the holding memory unit. The cell loss / mis-delivery detection processing method according to claim 1, further comprising the step of detecting cell loss and cell mis-delivery. 3. The receiving side of the performance management cell in the reverse direction has a holding memory unit for holding difference data between the transmission count value and the reception count value added to the performance management cell,
When the performance management cell is received, based on the difference between the transmission count value and the reception count value added to the performance management cell and the previous difference data read from the holding memory unit, cell loss and cell The cell loss / mis-delivery detection processing method according to claim 1, further comprising a step of detecting mis-delivery. 4. The difference data held in the holding memory unit is initialized by the difference data between the transmission count value and the reception count value when the performance management cell is received when the performance management cell is first received. The cell loss / misplacement detection processing method according to claim 1, further comprising: 5. The content of a memory unit that counts the number of received user cells after detection processing of cell loss and cell mis-delivery on the reception side of the performance management cell in the forward direction A process of updating using the transmission count value added to the performance management cell, and a performance management that generates a reverse performance management cell based on the forward performance management cell and counts the number of received user cells 2. The cell loss / misplacement detection processing method according to claim 1, further comprising the step of providing a cell counter and adding the reception count value of the performance management cell counter to the performance management cell and transmitting the added value. . 6. The difference data held in the holding memory unit is initialized by the difference data between the transmission count value and the reception count value at the time of reception of the performance management cell when the performance management cell is first received. And the content of the memory unit that counts the number of received user cells after the process of detecting cell loss and cell misdelivery is updated using the transmission count value added to the performance management cell in the forward direction. And a performance management cell counter for generating a reverse performance management cell based on the forward performance management cell and counting the number of received user cells, and receiving by the performance management cell counter. The cell loss / misdistribution detection processing method according to claim 1, further comprising a step of adding a count value to the performance management cell and transmitting the cell.