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OptiX OSN 7500 Intelligent Optical Switching System. Technical Manual - part 8

aturesOSN 7500

Technical Manual - System Description

8 Protection

8.2.6 Mesh Protection

The mesh network is not affected by node congestion and node failure. It achieves

higher reliability because there are multiple routes available between two nodes.

Compared with the ring network, the mesh network has the following advantages.

High bandwidth utilization, network scalability and survivability.

Suitable for the area with large and evenly distributed traffic.

8.2.7 Protection of Resilient Packet Ring

Figure 8-5 shows a bidirectional resilient Ethernet ring. Both the outer ring and the

inner ring transmit data packets and control packets. The control packet of the inner

ring carries the control information of the data packets in outer ring and the process for

the outer ring is reversed. The Ethernet ring has a merit that the packets sent to the

ring are assumed by each node would finally reach their respective destination,

regardless of which channel used. Because each node has only three kinds of

operation on the packet: packet insertion (insert a new packet to the ring), packet

forwarding (forward the packet), and packet dropping (drop the packet to the local site).

This merit greatly reduced the communication workload between nodes, especially

when compared with the mesh network that has to decide to forward to which port

according to each packet.

Node 4

Outer ring

Inner ring

Node 3

Node 5

RPR

Node 1

Node 2

Figure 8-5 Bidirectional RPR

Upon fiber cut, RPR can start wrapping and packet steering function. Wrapping is to

connect the outer ring with the inner ring at the two nodes adjacent to the fiber cut

point, as shown in Figure 8-8. Packet steering is to transmit the packet in the opposite

direction at the transmitting node, as shown in Figure 8-7. In either way, the packet

can reach the destination from the opposite direction and the failure time is less than

50ms. The OptiX OSN 7500 performs wrapping for general protection switching at the

beginning, and then performs steering when the new topology and service path are

established. Then no packet will be lost during protection switching and the switching

8-7

aturesOSN 7500

Technical Manual - System Description

8 Protection

time is shortened.

Node 4

Outer ring

Inner ring

Node 3

Node 5

RPR

Node 2

Node 1

Wapping

Figure 8-6 Wrapping of RPR

Node 4

Outer ring

Inner ring

Node 3

Node 5

RPR

Node 1

Node 2

Steering

Figure 8-7 Steering of RPR

8.2.8 VP-Ring/VC-Ring Protection

VP-Ring/VC-Ring protection switching on the ATM layer is similar to path protection

for SDH in principle and features, as shown in Figure 8-8. VP-Ring/VC-Ring protection

reserves protection resources to achieve protection. It can be used on any physical

topology. The reserved protection resources include routes and bandwidth.

8-8

aturesOSN 7500

Technical Manual - System Description

8 Protection

NE2

ATM service

Working path

ATM service

NE3

Protection path

NE1

NE4

Figure 8-8 VP-Ring/VC-Ring protection

The OptiX OSN 7500 provides 1+1 protection for VP/VC. ATM service is protected by

adopting the mode of dual-fed and selective receiving. Two connections (working path

and protection path) are created respectively between the source node NE1 and the

sink node NE3. Normally, the receive end selects the service transmitted over the

working path. When the primary ring fails, the receive end starts protection after

detecting relevant failure information, and switches the received service to the

protection path, thus achieving the protection of ATM service.

8-9

OAM

This chapter describes the maintenance capability and network management of the

OptiX OSN 7500. It covers:

Operation and maintenance

Administration

9.1 Operation and Maintenance

The OptiX OSN 7500 is designed with such a cabinet and boards, and set with such

functions as to meet the customers’ needs for operation administration and

maintenance (OAM) of the equipment.

The SCC board generates audible and visual alarms to remind the network

administrators to take proper measures in the case of any emergency.

Provides 16 alarm input interfaces, four alarm output interfaces, four cabinet alarm

indicator output interfaces, and alarm concatenation interfaces to facilitate

operation and management of the equipment.

All boards are provided with running and alarm indicators to help the network

administrators to locate and handle faults as soon as possible.

The subrack supports automatic laser shutdown (ALS) function of the single-mode

optical interface of the SDH interface unit and Ethernet interface unit.

It supports automatic online detection of optical power of SDH and Ethernet optical

interfaces.

The swappable optical module is adopted to provide optical interface boards.

9-1

facilitating maintenance.

Orderwire phone function is provided to ensure dedicated communication

channels for administrators at various stations.

By means of the NM system, the running and alarm status of the equipment at all

stations on the network are dynamically monitored.

In-service upgrade of board software and NE software is supported. Board

software and field programmable gate array (FPGA) supports remote loading, and

provides the functions of error prevention loading and resume download.

With remote maintenance function, the maintenance personnel can remotely

maintain the OptiX OSN 7500 through PSTN when the equipment goes faulty.

The PDH processing board provides pseudo-random code test function which

supports remote bit error test.

9.2 Administration

The OptiX OSN 7500 is uniformly managed by the iManager series transmission

network management system (NM system for short). Through the Qx interface or

human-machine language (MML) interface, the NM system can manage, maintain

and test the entire optical transmission system in terms of fault, performance,

configuration and security. The NM system improves the quality of network services,

lowers the maintenance cost and ensures rational use of network resources.

9-2

Technical Specifications

The technical specifications of the OptiX OSN 7500 are as follows

Optical interface performance

Electrical interface performance

Clock performance

Transmission performance

Power consumption of boards

Electromagnetic compatibility

Environmental index

Environment requirement

10.1 Optical Interface Performance

10.1.1 SDH Optical Interface

Table 10-1 shows the performance of the STM-1 optical interface of the OptiX OSN

7500.

Table 10-1 Performances of the STM-1 optical interface of the OptiX OSN 7500

Nominal bit rate

155520 kbit/s

Classification code

I-1

S-1.1

L-1.1

L-1.2

10-1

155520 kbit/s

Operating wavelength (nm)

1310

1550

Optical source type

LED

MLM

SLM

Mean launched optical power

-15 to -8

-5 to 0

(dBm)

Minimum sensitivity (dBm)

-23

-28

-34

Minimum overload point

-8

-10

(dBm)

Minimum extinction ratio (dB)

8.2

Table 10-2 shows the performance of the STM-4 optical interface of the OptiX OSN

7500.

Table 10-2 Performances of the STM-4 optical interface of the OptiX OSN 7500 STM-4

Nominal bit rate

622080 kbit/s

Classification code

I-4

S-4.1

L-4.1

L-4.2

Ve-4.2 (refer to

G.691)

Operating

1310

1550

wavelength (nm)

Optical source type

LED/MLM

MLM

MLM/SL

SLM

Mean launched

-15 to -8

-3 to +2

optical power

(dBm)

Minimum

-23

-28

-33

sensitivity (dBm)

Minimum overload

-8

point (dBm)

Minimum

8.2

extinction ratio

(dB)

Note: Formulated according to the basic rules, though adjustment and optimization are made to part of the

parameters

Table 10-3 shows the performance of the STM-16 optical interface of the OptiX OSN

7500.

10-2

Nominal bit rate

2488320 kbit/s

Classification code

I-16

S-16.1

L-16.1

L-16.2

L-16.2Je

V-16.2Je

U-16.2Je

Color

optical

interface

Operating

1310

1550

Fixed

wavelength (nm)

waveleng

Optical source type

MLM

SLM

Mean launched

-10

-5 to 0

-2 to

5-7

14 (Note

14 (Note 1)

Refer to

optical power

to -3

G.694.1

(dBm)

and

G.691

Minimum

-18

-27

-28

-33

(Note 2)

sensitivity (dBm)

Minimum overload

-3

-9

-10

point (dBm)

Minimum

8.2

extinction ratio

(dB)

Note 1: The optical power value is the optical power output from the optical amplifier board.

Note 2: Formulated according to the basic rules, though adjustment and optimization are made to part of the parameters.

Table 10-4 Performances of the STM-16 (FEC) optical interface of the OptiX OSN 7500

Nominal bit rate

2.66 Gbit/s

Classification code

Ue-16.2c

Ue-16.2d

Code meaning

FEC+BA(14dB)+PA

FEC+BA(17dB)+PA

Typical transmission distance

178km

189km

Operating wavelength (nm)

Complying with ITU-T G.694.1, such as 1550.12

Optical source type

SLM

Mean launched optical power

-2 to +3

(dBm)

Minimum sensitivity (dBm)

-31(APD)

Minimum overload point (dBm)

-9(APD)

Minimum extinction ration (dB)

Note: the parameters in the table are for the optical transmitter and receiver, not including optical

10-3

Table 10-5 shows the performance of the STM-64 optical interface of the OptiX OSN

7500.

Table 10-5 Performances of the STM-64 optical interface of the OptiX OSN 7500

Nominal bit rate

9953280 kbit/s

Classification code

I-64.1

S-64.2b

L-64.2b

Le-64.2

Ls-64.2

V-64.2b

Color optical

interface

Operating

1310

1550

Fixed

wavelength (nm)

wavelength

Optical source type

SLM

Mean launched

-6 to -1

-1 to +2

10 to 13

1-4

3-5

12-15

Refer to

optical power (dBm)

(Note 1)

G.692 and

G.691 (Note

Minimum sensitivity

-11

-14

-22.5

-24

-23

(dBm)

Minimum overload

-1

-3

-9

-7

point (dBm)

Minimum extinction

8.2

ration (dB)

Maximum dispersion

6.6

800

1600

1200

1600

800

(ps/nm)

Note 1: The optical power value is the optical power output from the optical amplifier board.

Note 2: Formulated according to the basic rules, though adjustment and optimization are made to part of the

Parameters.

Table 10-6 Performances of the STM-64 (FEC) optical interface of the OptiX OSN 7500

Nominal bit rate

10.71 Gbit/s

Classification code

Ue-64.2c

Ue-64.2d

Code meaning

FEC+BA(14dB)+PA+DCU

FEC+BA(17dB)+PA+DC

(60km

80km)

U (80km x 2)

Typical transmission

167km

178km

distance

Operating wavelength (nm)

Complying with ITU-T G.694.1, such as 1550.12

Optical source type

SLM

10-4

10.71 Gbit/s

Mean launched optical power

-4 to -1

(dBm)

Minimum sensitivity (dBm)

-17(FEC off) / -19(FEC on)

-17(FEC off) / -19(FEC

(Note1)

on)

Minimum overload point

-1(FEC off) /+1(FEC on)

(dBm) (Note1)

Minimum extinction ration

(dB)

Maximum dispersion (ps/nm)

800

Note: the parameters in the table are for the optical transmitter and receiver, not including optical amplifiers

and dispersion compensation unit.

Table 10-7 shows performance of the STM-16 and STM-64 fixed wavelength optical

interface.

Table 10-7 Performance of the STM-16 and STM-64 fixed wavelength optical interface

Nominal bit rate

2488320 kbit/s

9953280 kbit/s

Application code

8 x 22 dB

5 x 30 dB

3 x 33 dB

1 x 29 dB

Despersion limit

170

640

(km)

Mean launched

-2 to 3

5 to 7

-5 to -1

-4 to -1

power (dBm)

Receiver minimum

-28

-8

-17

sensitivity (dBm)

Minimum overload

-9

-1

point (dBm)

Maximum

3500

12800

800

chromatic

dispersion (ps/nm)

Minimum

8.2

extinction ratio

(dB)

Table 10-8 shows the nominal central wavelength and frequency of the STM-16 and

STM-64 optical interfaces.

10-5

No.

Frequency

Wavelength

No.

Frequency

Wavelength (nm)

(THz)

(nm)

(THz)

192.1

1560.61

194.1

1544.53

192.2

1559.79

194.2

1543.73

192.3

1558.98

194.3

1542.94

192.4

1558.17

194.4

1542.14

192.5

1557.36

194.5

1541.35

192.6

1556.56

194.6

1540.56

192.7

1555.75

194.7

1539.77

192.8

1554.94

194.8

1538.98

192.9

1554.13

194.9

1538.19

193.0

1553.33

195.0

1537.40

193.1

1552.52

195.1

1536.61

193.2

1551.72

195.2

1535.82

193.3

1550.92

195.3

1535.04

193.4

1550.12

195.4

1534.25

193.5

1549.32

195.5

1533.47

193.6

1548.51

195.6

1532.68

193.7

1547.72

195.7

1531.90

193.8

1546.92

195.8

1531.12

193.9

1546.12

195.9

1530.33

194.0

1545.32

196.0

1529.55

10.1.2 Ethernet Optical Interface

The performance of the GE optical interface of the OptiX OSN 7500 conforms to IEEE

802.3z, and that of the ME optical interface conforms to IEEE 802.3u, as shown in

Table 10-9.

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