ONS 15454 MSTP DWDM Design Rules Examples

The various transponder/muxponder interface cards used in the ONS 15454 MSTP exhibit unique transmitter and receiver characteristics. A typical DWDM design uses a wide range of these transponder/muxponder interfaces at varying bit rates. For reference, Table 10-1 details the ONS 15454 MSTP transponder/muxponder transmissions characteristics.

Table 10-1. ONS 15454 MSTP Transponder/Muxponder Trunk Optics Specifications

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Depending on which transponder/muxponder type is being used, the optical span design rules slightly differ. Tables 10-2 through 10-4 enumerate the ONS 15454 MSTP design rules for the linear and ring topologies specified in Chapter 9. Note the following assumptions/details associated with the design rules:

• The given design rules cover SMF fiber only.

• Full 32-channel loading is assumed.

• Where dispersion compensation units (DCUs) are placed, the DCU fiber attenuation is assumed to be 9 dB (worst case for the OPT-PRE).

• Both PRE/booster amplifiers are used on amplified spans.

• Where no optical add/drop multiplexers (OADMs) are used, only the OPT-PRE is installed.

• Assume equal span losses, with fixed OADM nodes having a loss of 16 dB.

• The optical preamplifier (OPT-PRE) is engineered for constant gain mode but switches to constant power mode when span losses exceed 27 dB. (This is not applicable to reconfigurable add/drop multiplexers [ROADM].)

Table 10-2 details the ONS 15454 MSTP design rules for linear networks, without OADM placement.

Table 10-2. ONS 15454 MSTP Linear (No OADM) Span Loss Design Rules

Number of Spans	10ME-xx.x (standard FEC) 10E-L1-xx.x (standard FEC)	10ME-xx.x (no FEC)	MR-L1-xx.x (standard FEC) MRP-L1-xx.x (standard FEC)	MR-L1-xx.x (no FEC) MRP-L1-xx.x (no FEC DM-L1-xx.x DMP-L1-xx.x	MR-L1-xx.x (2R, no FEC) MRP-L1-xx.x (2R, no FEC)	10ME-xx.x (enhanced FEC) 10E-L1-xx.x (enhanced FEC)
1x	35 dB	25 dB	37 dB	33 dB	30 dB	37 dB
2x	27 dB	19 dB	30 dB	26 dB	23 dB	29 dB
3x	24 dB	17 dB	26 dB	23 dB	20 dB	25 dB
4x	22 dB	14 dB	24 dB	21 dB	19 dB	23 dB
5x	21 dB		22 dB	20 dB	18 dB	22 dB
6x	20 dB		21 dB	19 dB	17 dB	21 dB
7x	19 dB		20 dB	18 dB	16 dB	20 dB

With this configuration, there is no DWDM wavelength channel insertion/drop capacity at midspan nodes. For multispan sites, the midspan shelf is configured as a line amplifier. Table 10-3 details the configuration that allows for intermediate DWDM wavelength channel add/drop.

Table 10-3. ONS 15454 MSTP Linear with OADM Span Loss Design Rules

Number of Spans	10ME-xx.x (standard FEC) 10E-L1-xx.x (standard FEC)	10ME-xx.x (no FEC)	MR-L1-xx.x (standard FEC) MRP-L1-xx.x (standard FEC)	MR-L1-xx.x (no FEC) MRP-L1-xx.x (no FEC DM-L1-xx.x DMP-L1-xx.x	MR-L1-xx.x (2R, no FEC) MRP-L1-xx.x (2R, no FEC)	10ME-xx.x (enhanced FEC) 10E-L1-xx.x (enhanced FEC)
1x	35 dB	25 dB	37 dB	33 dB	30 dB	37 dB
2x	29 dB	20 dB	31 dB	27 dB	25 dB	30 dB
3x	26 dB	15 dB	29 dB	25 dB	23 dB	28 dB
4x	24 dB		26 dB	23 dB	20 dB	25 dB
5x	23 dB		25 dB	22 dB	16 dB	24 dB
6x	21 dB		24 dB	19 dB		23 dB
7x	20 dB		23 dB	16 dB		22 dB

Networks that use fixed-channel OADMs allow for planned DWDM channel insertion/deleting. However, as noted in Chapter 9, the most flexible ONS 15454 MSTP DWDM topology consists of ROADMs. The ROADM ring and linear topology configuration rules are enumerated in Table 10-4. Although fixed-channel and ROADM nodes can coexist in a ring/linear topology, Table 10-4 addresses only the case in which all add/drop nodes are configured as ROADM.

Table 10-4. ONS 15454 MSTP ROADM Span Loss Design Rules

Number of Spans	10ME-xx.x (standard FEC) 10E-L1-xx.x (standard FEC)	10ME-xx.x (no FEC)	MR-L1-xx.x (standard FEC) MRP-L1-xx.x (standard FEC)	MR-L1-xx.x (no FEC) MRP-L1-xx.x (no FEC DM-L1-xx.x DMP-L1-xx.x	MR-L1-xx.x (2R, no FEC) MRP-L1-xx.x (2R, no FEC)	10ME-xx.x (enhanced FEC) 10E-L1-xx.x (enhanced FEC)
1x	35 dB	25 dB	37 dB	33 dB	30 dB	37 dB
2x	30 dB	20 dB	34 dB	28 dB	25 dB	32 dB
3x	28 dB	17 dB	32 dB	26 dB	23 dB	30 dB
4x	26 dB		30 dB	24 dB	21 dB	28 dB
5x	25 dB		29 dB	23 dB	20 dB	27 dB
6x	24 dB		28 dB	22 dB	18 dB	26 dB
7x	23 dB		27 dB	21 dB	14 dB	25 dB
8x	22 dB		26 dB	20 dB		25 dB
9x	21 dB		25 dB	19 dB		24 dB
10x	21 dB		25 dB	18 dB		23 dB
11x	18 dB		24 dB	17 dB		23 dB
12x	17 dB		24 dB	15 dB		22 dB
13x	15 dB		23 dB			22 dB
14x			23 dB			21 dB
15x			22 dB			21 dB

The design rule summaries given in Tables 10-2, 10-3, and 10-4 do not represent the full capabilities of the ONS 15454 MSTP. The MSTP DWDM system is fully capable of operating on NZDF fiber, with various channel count and OADM combinations. The DWDM design engineer should consult the latest installation and operations guide for the ONS 15454 MSTP for an exhaustive list of design rules.