The operational standards for the reference of the international chain of 27 500 km long

Channel (Truct)	Transmission speed Mbit/s	The value of B operational standards
ESR	SESR
MDC	0,064	0,04	0,001
CT	От 1.5 до 5.0	0,02	0,001
От 5.0 до 15	0,025	0,001
От 15 до 55	0,0375	0,001
От 55 до 160	0,08	0,001
От 160 ….		-

Table.P-15.3.

Some of the operational standards,
taking into account the actual length and type of area the primary network

Backbone PN	Intrazone PN
Length LФ Less or equal (km)	D1	Length LФ Less or equal (km)	D2
	0,015		0,026
	0,02		0,040
	0,022		0,052
	0,024		0,065
	0,026		0,075
	0,027
	0,029

2. We define the boundary values of errors S1 and S2 during the selected time Тsec.

 

(Table.P-15.2)

S1 = R₀ – 2х

S2 = R₀ + 2х

3. Compare the measured value of the parameter S - S(ESR) or S(SESR) to the threshold values of S1 and S2.

If

S < S1, then the input of the CT in operation is allowed,

If

S > S2, the measurement of the CT for the operation is not good,

If

S1 < S < S2, for the assessment of the possibility to enter the CT in operation it is necessary to continue measuring, increasing the time of measurement.

 

 

Bit error ratio BER:

BER = (Nbit-err/ Nbit-sum) for the time of the measurements Тmeas

In accordance with the definition of N_ES and N_SES

Nbit-err= N_ES + 300* N_SES

There are 300 = 30% of 1000 blocks with one or more errors per second.

Nbit-sum= Тmeas ( sec )* 2,048*10⁶ bit

In its turn

N_ES = ESR * Тmeas (sec)

N_SES = SESR*Тmeas (sec)

So

BER = (ESR * Тmeas +300* SESR*Тmeas)/ Тmeas * 2,048*10⁶

BER = (ESR +300* SESR)* 5*10^-7

BER = ESR * 5*10^-7 + SESR* 1,5*10^-4

 

	BER ≈ SESR* 1,5*10-4
		(Table.P-15.3.)

 

If we believe that SESR=0, taking into account only the background bugs

	BER ≈ ESR * 5*10-7		(Table.P-15.4)

 

 

Link of BBER with coefficients ESR, SESR and BER:

 

BBER = N_BBE/N_B

BBER = ESR*N_S/(1000*N_S - 300*SESR*N_S)

BBER = ESR*10^-3/(1- 0.3*SESR)

	BBER ≈ ESR*10-3

 

 

So-as the length of the block E1 is 2048 bits, the

BER ≈ BBER*5*10-4

	(Table.P-15.5)

 

 

(Table.P-15.4)

Which coincides with с

 

 

Let us consider an example-1:

Determine the long-term norms of quality indicators in the digital path E1 zone area length L_Ф = 240 km on the basis of РРСП.

For intra-zone area С = С2 = 0,075;

 

Quality factor	Calculations	Number
ESR	0.04 х 0,075 = 0,003	3х10-3
SESR	0.002х 0,075 + 0.0005 = 0,00065	6,5х10-4
BBER	3 ´ 10–4х 0,075 = 0,225х 10–4	2,2х10-5
BER   taking into account only the background bugs

ES