SDH Presentation

-SDH Basics-Alcatel SDH Systems-Alcatel 1662SMC Introduction-SDH Link No.17

SDH Basics

What are SDH & PDH ?

Advantages of SDH over PDH.

SDH Data rates.

SDH Multiplexing Structure.

SDH Basic Frame Structure.

SYNCHRONOUS DIGITAL HIERARCHY

SDH Basics What are SDH & PDH ?

SDH stands for Synchronous Digital Hiararchy.In SDH each and every signal is synchronized exactly to the single (container) defined for that particular signal ( like C11,C12,etc).The techniques like bit stuffing and bit justification are adopted in SDH to achieve the synchronization.

The signal used for SDH transmission is known as Synchronous Transport Module (STM). The various STM rates are illustrated below STM-1 (155.52 Mbps)

STM-4 (622.08 Mbps)STM-16 (2488.32 Mbps)

STM-64 (9953.28 Mbps)STM-256 (39813.12 Mbps)

SDHMUX

SDHMUX

SDHMUX

SDHMUX

STM-1

STM-1

STM-1

STM-1 STM- 4

STM- 4

STM- 4

STM- 4

STM- 16

STM- 16

STM- 16

STM- 16

STM- 64

STM- 64

STM- 64

STM- 64

STM- 256

PLESIOCHRONOUS DIGITAL HIERARCHY

Plesio means = similar

Chronous means= Timing

Plesiochronous – “almost synchronous”,

because the digital signals being multiplexed together are not

at quite the same frequency

PDH (Plesiochronous Digital Hierarchy)

SDH Basics What are SDH & PDH ? (continues…)

PDH stands for Pleisynchronuous Digital Hiararchy.The PDH contains the signals having similar data rate signals (like E1,E 2,E3,T1,T2,etc.) but with slight timing differences as shown below.E1 – 2.048 Mbps [32 x 64 kbps (DS0)]E2 – 8.448 Mbps [4 x E1]E3 – 34.368 Mbps [4 x E2]E4 – 139.264 Mbps [4 x E3]

PDHMUX

PDHMUX

PDHMUX

E1(2.047990 Mbps)

E1(2.048001 Mbps)

E1(2.047992 Mbps)

E1(2.048000 Mps)

E2(8.447997 Mbps)

E3(34.367998Mbps)

E3(34.367990Mbps)

E3(34.368000Mbps)

E3(34.367989Mbps)

E2(8.447991 Mbps)

E2(8.448000 Mbps)

E2(8.447989 Mbps) E4(139.264000Mbps)

SDH Basics Advantages of SDH over PDH

High Transmission Rates:The highest data rate that can be achieved with PDH technologies is 140 mbps, whereas the transmission rates up to 10Gbps (STM-64) can be achieved with SDH technology.

Easy Add & Drop Functionality:Compared to the older PDH system, low bit rate channels can be easily extracted from and inserted into the high-speed bit streams in SDH. It is now no longer necessary to apply the complex and costly procedure of demultiplexing then remultiplexing the plesiosynchronous structure.

High Availability and Capacity matching:With SDH, network providers can react quickly and easily to the requirements of their customers. For example, leased lines can be switched in a matter of minutes. The network provider can use standardized network elements (NE) that can be controlled and monitored from a central location via a telecommunications management network (TMN) system.

Reliability:Modern SDH networks include various automatic back-up circuit and repair mechanisms (like Automatic Protection Switching (APS) and Equipment Protection Switching (EPS) which are designed to cope with system faults and are monitored by management. As a result, failure of a link or an NE does not lead to failure of the entire network .

Integrated Services:SDH is the ideal platform for a wide range of services including POTS, ISDN,mobile radio, and data communications (LAN, WAN, etc.). It is also able to handle more recent services such as video on demand and digital video broadcasting via ATM.

Changing from one hierarchical level to another requires additional equipment.For Add/drop of individual channels from the higher order stream we have to disassemble / reassemble it Redirection (cross-connection) of channels must be done by hand on DDFs. Administrative connections require separate equipment to support Supervision, EOW and protection switching. Compatibility of transmission and administrative signals between different vendor may give trouble.

Disadvantages of PDH

SDH Basics

SDH Data rates:

STM-0 (51.84 Mbps)STM-1 (155.52 Mbps)STM-4 (622.08 Mbps)STM-16 (2488.32 Mbps) STM-64 (9953.28 Mbps)STM-256 (39813.12 Mbps)

Note: The STM-0 is not widely used in the telecom network except for some Microwave Links.

SDH Basics SDH Multiplexing Structure:

C11VC11TU-11

C12VC12TU-12

C2VC2TU-2TUG-2

C3VC3AU-3STM-0

TU-3 VC3

C4

TUG-3

VC4AU-4AUGSTM-N

T-1(1.544Mbps)OrATM(1.6Mbps)

E-1(2.048Mbps)OrATM(2.144Mbps)

T-2(6.312Mbps)OrATM(6.874Mbps)

T-3(44.736Mbps)OrE-3(34.368Mbps)OrATM(48.384Mbps)

E-4(139.264Mbps)OrATM(149.760Mbps)

x1xN

x4

x3

x1

x7

x3

Containers

Virtual Containers (Containers + POH)

Tributary Units/Administrative Units(Virtual Containers + Pointers)

Tributary Unit Groups/Administrative Unit Groups(Multiplexed structures of lower signals)

AlignmentMultiplexing

SDH Multiplexing Structure:

KLM DETAILS K-TUG 3 L-TUG 2 M-TU 12

First KLM combination is 1 1 1 Last KLM combination is 3 7 3

• E1 = 32 bytes/frame• C12 = 34 bytes/frame (E1 +2 stuffed bytes)• VC12 = 35 bytes/frame (C12 + 1 POH byte )• TU12 = 36 bytes/frame (VC12 +1 pointer byte) M So, one TU12 occupies 4 columns(36 bytes) in an STM1 frame

• TUG-2 = 3 X TU12 = 12 columns /frame L• TUG-3 = 7 X TUG-2 = 86 columns /frame K

(7 X 12 + 2 stuffed columns are added)

• VC4 = 3 X TUG-3 = 261 columns /frame(3 X TUG-3 + 2 stuffed columns + 1 POH)

• STM1 = VC4 + SOH = 261+ 9 = 270 columns /frame.

Mapping of 63 E1s into STM1

1.Container Cn, where C=Container,n=Index of the container(n=11,12,2,3,4) The rate of the container depends on the signal which is transported.

2.Virtual container VCn,It is made up of Cn and Poh Vcn=Cn+Poh,where Poh is path over head Pathover head contain Payload content

3.Tributary unit TUn=VCn+PTR n=11,12,2,3 lower oder VCn Where Pointer is an addittional rate used to locate its Vcn with in the TU

4.Tributary unit Group TUG-k=m*TU-n, where k=2,3 n=11,12,2,3 TUG ,the Tug-2/Tug-3 can consist of several types of capacity payloads with different sizes.

5.Adminitrative Unit(AU),it is made up of higher order VCn(n=3,4) and a pointer AUn=VCn+PTR n=3,4 AUG=1*AU-4 or 3*AU-3

SDH Basics SDH Basic Frame Structure (STM-1):

Each cell represents a single byte indicating a 64 kbps channel.RSOH :- Regenerator Section Overhead (27 bytes )MSOH :– Multiplexer Section Overhead (45 bytes)Total Section Overhead (SOH) :– RSOH + MSOH AU-4 Pointer :- 9 bytesPayload :- 261 x 9 = 2349 bytesSTM -1 Data rate = (270 x 9) bytes

= 2430 bytes = 2430 x 64 kbps = 155520 kbps = 155.52 Mbps

RSOH(3 x 9 Cells)

PAYLOAD (261 x 9 Cells )AU-4 POINTER

MSOH(4 x 9 Cells)

11

9 10

3

4

5

9

270

270 Colomns

9 Rows

SDH Basics SDH Basic Frame Structure (STM-1) (Continues….):

Section Overhead (SOH )

X – Bytes Reserved for national use.* - Media Dependant Bytes

A1 A1 A1 A2 A2 A2 J0 X X

B1 * * E1 * F1

D1 * * D2 * D3

AU-4 Pointer

B2 B2 B2 K1 K2

D4 D5 D6

D7 D8 D9

D10 D11 D12

S1 M1 E2 X X

SDH Basics SDH Basic Frame Structure (STM-1) (Continues….): Overhead Bytes Functions

Overhead Byte Functions

A1,A2 Frame Alignment

B1,B2 Quality Monitoring , parity bytes

D1,D2,D3 Qecc Network Management

D4,………..,D12 Qecc Network Management

E1,E2 Voice Connections

F1 Maintenance

J0 Trace Identifier

K1,K2 Automatic Protection Switching (APS) Control

S1 Clock Quality Indicator

M1 Transmission Error Acknowledgement

Alcatel SDH SystemsAlcatel SDH Systems

1662SMC 1642 1660SM

Version 2(R2)Version 1(R1) Version 5(R5)Version 4(R4)

SupportsUpto STM-4

SupportsUpto STM-16 Supports

Upto STM-16Supports

Upto STM-64

Supports Upto STM-1

Alcatel 1662 SMC Introduction

Features

Shelf View

Commonly used cards

Technical Specifications

Features: It complies with the Synchronous Digital Hierarchy (SDH) defined in ITU-T

Recommendation G.707.

Compatible with existing plesiochronous systems as well as with the installed SDH networks,

The 1662SMC is transmission equipment operating at 155.520 Mbit/s (STM-1) , 622.080 Mbit/s (STM-4) and 2488.320 Mbit/s(STM-16).

It can be configured as a Multiple Line Terminal Multiplexers or as a Add/Drop Multiplexers or as a Mini local cross-connect for applications in linear links, network rings and meshed networks.

Equipment (EPS) and network (MSP) protection mechanism

Matrix capacity 96*96 stm-1 equivalent matrix(HO) 64*64 stm-1 equivalent matrix(LO) Network interfaces: Stm-1/4/16 Customer interfaces: 2Mbps,34/45Mbps,140Mbps,ethernet,gigaethernet

Alcatel 1662 SMC Introduction

PONDICHERRY CUDDALORE CHIDAMBARAM KUMBAKONAM

TANJORE TRICHY

ALCATEL SDH LINK-17 PONDY TO TRICHY: STM 4 LINK

26km 49km 65km

50km 54km

Total Pondy – Trichy : 244 KMS

Fiber Owner : BTSOL

Fiber allotted for vsnl/Ttsl : F no 39 – F no 48

Fiber used for SDH : F no 43&44

Link name & no : SDH LINK No 17

Alcatel 1662 SMC Introduction Shelf View:

- Total Slots : 20- Access Area 1: Slot 1-5 ( Hosts Access Cards like A63E1, A4S1, Congi ,etc).- Access Area 2: Slot 16-20 ( Hosts Access Cards like A63E1, A4S1, Sergi ,etc).- Port(Basic area)Area: Slot 6-15 (Hosts Port Cards like SYNTH, P4S1, P63E1, etc).

ACCESS AREA-1 PORT AREA ACCESSAREA-2

CARDS USED IN THE ALCATEL SDH LINK-17

1. Congi card : It the used to control the whole SDH system. It consists of power supply&house keeping unit. the congi card is in slot no1

2. Synth4Card: It is card used to insert the optical signals from the fms.It consists the Optical module it is named as IL- 4.2,IL-1.2,IS- 1.1.- these are called Optical modules. There are two synth cards its inserted in slot no 6&15.

3. P4S1N card: P indicates Port ,S1N indicates STM1. card

4. P63E1 card : P indicates port, 63 E1 indcates Electical signals.

5. A63E1-120 : it’s a card corresponding to P63E1 card.A indicates access area.

6. LSPORT/HSPROT: Its is a Low Speed/High speed protection Card. It is used to implement EPS protection.(i.e)it implements the connection between the access and spare card.These cards receive the signal coming from the access card via back panel.

7.SERGI CARD: Used as a stand by card for the CONGI CARD8. IL- It indicates LONG HAL it should in corresponding SYNTH CARD.9. IS- It indicates SHORT HAL .

Note: 1. For All cards corresponding stand by cards are used.2. Inserting a port card we have to insert a corresponding acess card in the particular slot.3. Port area : Corresponding Acess area Slot No-7 : No-2 Slot No-8 : No-3 Slot No-9 : No-4 Slot No-10 : No-5 Slot No-11 : No-16 Slot No-12 : No-17 Slot No-13 : No-18 Slot No-14 : No-194. Congi card in Slot no- 15. Sergi card in Slot no-206. Synth card in slot no:6,15

Alcatel 1662 SMC Introduction Commonly Used Cards:

P63E1 processes 63 2Mbits/s signals whose accesses are on the relevant Access cards A21E1,A63E1 P4ES1N handles four electrical STM-1 Signals.All four accesses are on the relevant access card(A4ES1).It is one of the board that can be EPS protected. P3E3T3 Prt card is a bi-directional interface from/to three PDH streams at 34Mbits/s or at 45Mbits/s Switchable and the STM-4

(1) Multicolor LED: Red led . local unit alarm Green led . in service unit Orange led . unit in stand-by (EPS schema)

ACRONYM SLOTS

P63E1N 7,8,9,10,11,12,13,14

P4ES1N 7,8,9,10,11,12,13,14

P3E3T3 7,8,9,10,11,12,13,14

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

P4ES1N handles four electrical STM-1 signals.All the four accesses are on the Relevant Access card(A4ES1).It can be EPS protected.

P4E4N it describes the same features of P4S1N. Two STM-1 electrical modules(Electricl or optical )can be hosted on the board. Two further STM-1 modules can be hosted on the Access card A2S1

LEGEND: (1) Channel #1 (N.B.) (2) Channel #2 (N.B.) (3) Bicolor LED: Red led . local unit alarm Green led . in service unit

ACRONYM SLOTSP4ES1N 7,8,9,10,11,12,13,14P4E4N 7,8,9,10,11,12,13,14

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

1662SM-C houses two congi card(i.e)congi-A and congi-B CONGI-A hold the Equip MAC(media access control) address

LEGEND:(1) Power(2) Housekeeping and remote alarm(3) Rack lamp (not used in slot 20)(4) QMD Q2 (not used in slot 20)(5) I/O BNC Q3 10base2 (not used in slot 20)(6) RJ45 Q3 10baseT (not used in slot 20)(7) Bicolor LED:Red led . local unit alarmGreen led . in service unit

ACRONYM SLOTSCONGI 1, 20

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

Sergi card Provides reduced combination of congi and service card functions It has Power interface,Auxillary interface,I/p o/p clock interface for NE synchronization

LEGEND:(1) Power(2) Auxiliary channels:2 channels G.7032 channels RS2322 channels V.11(3) Aux and Sync. 2Mbit/sJ1 . 2MHz Input (T3) or 2Mbit/s Input (T6)J2 . 2Mbit/s Input channelJ3 . 2MHz output (T4) or 2Mbit/s output (T5)J4 . 2Mbit/s output channel(4) Four wire telephone extersion point (RJ11)(5) Z1-Z4 EOW zone selection LEDs (N.B.1)(6) L1-L2 LEDs status for selective and multiplecall (N.B.2)(7) Telephone jack(8) Line seizure Key(9) EOW zone selection Key(10) Reset command Key(11) Bicolor LED:Red led . local unit alarmGreen led . in service unit

ACRONYM SLOTSSERGI 20

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

SYNTH16 can be EPS 1+1 Protected Slot no:6 is main card Slot no:15 is spare card Synth16 card is equipped with two parts for modules 1*STM-16 signals can be processed by the SYNTH 16 card Synth 16 card performs several fns like shelf controller,Equip controller, Performance monitoring collection,remote inventory Synth 16 cards have a 96*96 stm-1 Matrix capacity. It is also called as Compact ADM16 Card

LEGEND(1) Reset command key(2) Channel #1 (N.B.)(3) Lamp test pushbutton(4) Personal Computer Connector (F interface)(5) Red LED . Urgent Alarm (Critical or Major)(6) Red LED . Not Urgent Alarm (Minor)(7) Yellow LED . Alarm storing (Attended)(8) Yellow LED . Abnormal condition(9) Yellow LED . Indicative Alarm (Warning)(10) Green LED . when on it means active unitwhen off it means standby unit(11) Bicolor LED:Red led . local unit alarm (INT)Green led . in service unit(12) Alarm storing pushbutton (Attended)

ACRONYM SLOTSSYNTH16 6,15

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

A63E1 is the access card for the P63E1 63*2Mbit/s Access card(A63E1)Provides the connections from backpanel to the external line and vice versa for the 63 PDH signals. Three different type of connectors available: A63E1/A:75 ohms unbalanced A63E1/B:120 ohms balanced A63E1/C:75 Ohms unbalanced with coax(3 slot wide) LEGEND(1) Channel #1-7(2) Channel #8-14(3) Channel #15-21(4) Channel #22-28(5) Channel #29-35(6) Channel #36-42(7) Channel #43-49(8) Channel #50-56(9) Channel #57-63

ACRONYM SLOTSA63E1B (120Ohm)

2,3,4,5,16,17,18,19

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

A2S1 is the access card for the P4S1N and P4E4N port cards. A2S1 can host upto 2modules(optical stm-1) in the front panel.

LEGEND(1) Channel #3 (N.B.)(2) Channel #4 (N.B.)(3) Bicolor LED:Red led . local unit alarmGreen led . in service unit

ACRONYM SLOTSA2S1 2,3,4,5,16,17,18,

19

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

A3E3 Provides 3*34Mbit/s accesses for the P3E3T3 A3T3 Provides 3*45Mbit/s accesses for the P3E3T3 For each P3E3T3 One A3E3,A3T3 is necessary

LEGEND(1) Channel #1(2) Channel #2(3) Channel #3(4) Bicolor LED:Red led . local unit alarmGreen led . in service unit

ACRONYM SLOTS

A3E3 2,3,4,5,16,17,18,19A3T3 2,3,4,5,16,17,18,19

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

A4ES1 Provides 4 STM-1 Accesses for the P4ES1N. For each P4ES1N one A4ES1 is Necessary

LEGENDA(1) Channel #1(2) Channel #2(3) Channel #3(4) Channel #4(5) Bicolor LED:Red led . local unit alarmGreen led . in service unit

ACRONYM SLOTSA4ES1

2,3,4,5,16,17,18,19

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

MODULEACRONYM

EQUIPEDON PORTS

S-1.1 P4S1N,P4ES1ATM4X4,A2S1SYNTH4

L-1.1L-1.2

S-1.1S-Stands for short haul1-stands for stm-11-stands for representing 1310nm

L-1.1L-Stands for Long haul1-stands for stm-11-stands for representing 1310nm

Module types:Stm-1 and stm-4 Optical module:SC-PC Type and Fc-Pc Type are availableStm-1 & stm-4 Optical modules are available and it physically different140Mbit/s-STM-1 Electrical module.

Alcatel 1662 SMC Introduction Commonly Used Cards ( continues..):

LEGENDA(1) Multicolor LED:Red led . local unit alarmOrange led . temperature major than 55° CGreen led . in service unit(2) Battery A connector(3) Battery B connector(4) Alarms connector for 1662SMC on the Left side of the Rack(5) Not used(6) Alarms connector for 1662SMC on the Right side of the Rack (6)

PSC front view

HWF

POWER

+ VBATT (male)

GND (female)

-VBATT (male)

Alcatel 1662 SMC Introduction Technical Specifications:Safty First-The optical interfaces which have HAZARD LEVEL 3A (see Table A below ) carry the following hazard symbol label:

Caution : Invisible Laser Radiation may be present inside the optical interfaces carrying the above label ,hence NEVER directly view into the beam.Doing so may result in the permanent damage to the eyesight.

UNIT/PORT OPTICAL INTERFACE HAZARD LEVELSTM.1 S.1.1 (short haul) 1STM.1 L.1.1 (long haul) 3ASTM.1 L.1.2 (long haul) 3ASTM.4 S.4.1 (short haul) 1STM.4 L.4.1 (long haul) 3ASTM.4 L.4.2 (long haul) 3ASTM.16 S.4.1 (short haul) 3ASTM.16 L.4.1 (long haul) 3ASTM.16 L.4.2 (long haul) 3A

CLASSIFICATION OF ALARMS SEVERITY ALARMS SYNTHESIS 1.Critical Alarms 2.Major Alarms 3.Minor Alarms 4.Warning Alarms 5.Intermediate Alarms

DOMAIN ALARMS SYNTHESIS 1.Synchronization Alarms 2.External points(House keeping Alarms) 3.Transmission Alarms 4.Equipment Alarms

MANAGEMENT ALARMS SYNTHESIS 1.Supervision 2.Alignment 3.Local access 4.Operating system 5.Managed by Nm & RM 6.Abnormal condition

Power -48V DC, 6A

MCB Rating used in the TRU unit is 16A

The max current consumed by the Equipment is less than 4Amps

A/C environment with temperature, humidity and dust control

Fire safety by centralised monitoring and automatic operation of extinguisher

LCT access through Q interface for NMS access through the LAN card

Tools: Power source, power meter, OTDR (Optical Time Domain Reflectometer) and OSA (Optical Spectrum Analyser)

Technical Specifications (Continues…):Electrical Interface Characteristics-

Alcatel 1662 SMC Introduction

Interface Charaterisitics

P63E1 Bit rate 2048 Kbit/s ±50 ppmNo. of channels 63Line Code HDB3Signal amplitude 2.37 Vp on 75 Ohm

unbalance/ 3 Vp on 120 Ohm balance.

P3E3 Bit Rate 34368 Kbit/s ±20 ppm

No. of tributaries 3

Line Code HDB3

Signal amplitude 1Vp/75ohms

P3T3 Bit rate 44.736 Kbit/s ± 20ppm

No. of tributaries 3

Line Code B3ZS

P4S1E Bit rate 155 520 Kbit/s ± 20 ppm

Line Code CMI

P4E4 Bit rate 139264 Kbit/s ±15 ppm

Line Code CMI

Alcatel 1662 SMC Introduction Technical Specifications (Continues…):Optical Characteristics –

STM-1 S 1.1 L 1.1 L 1.2

Trans Power -15 to -8dB 0 to - 5dB0 to - 5dB

Receiver Sensitivity -28dB -37dB -37dB

Receiver Overload -8dB -10dB -10dB

Optical Connectors – FCPC/SCPC

STM-4 S 4.1 L 4.1 L 4.2

Trans Power -15 to -8dB 2 to -3dB2 to -3dB

Receiver Sensitivity -28dB -28dB -28dB

Receiver Overload -8dB -8dB -8dB

Optical Connectors – FCPC/SCPC

STM-16 S 16.1 L 16.1 L 16.2

Trans Power 0 to -5dB 2 to -2dB2 to -2dB

Receiver Sensitivity -18dB -27dB -28dB

Receiver Overload 0dB -8dB -8dB

RS232 Pin Assignments (DB9 PC signal set)

Pin 1 Received Line Signal Detector(Data Carrier Detect)

Pin 2 Received Data

Pin 3 Transmit Data

Pin 4 Data Terminal Ready

Pin 5 Signal Ground

Pin 6 Data Set Ready

Pin 7 Request To Send

Pin 8 Clear To Send

Pin 9 Ring Indicator

The connector on the PC has male pins, therefore the matingcable needs to terminate in a DB9/F (Female pin) connector

PROTECTION TYPES

EPSEquipment Protection Switching

MSPMultiplex Section

Protection

1:1 1:N

MSP-LINEARMS-SP RINGSNCP/NSNCP/I

EPS:Protection against the equipment failure MSP:Protection against the equipment failure And the Line Failure

EPS(Equipment Protection Switching)

EQUIPMENT 1

EQUIPMENT 2

1.The 1+1 EPS Protection type means that one working equip is Protected by One Redundant Equip

2.The mode of 1+1 EPS Protection is Non Revertive.

1+1 Type

EPS(Equipment Protection Switching) 1:N Type

EQUIPMENT 1

EQUIPMENT 1

EQUIPMENT N

EQUIPMENT P

LINE 1

LINE 2

LINE N

1)1:N Type protection means that N working Pieces of equip are protected by just 1 Portecting Equivalent.

2)The mode of 1:N Eps protection is revertive.

MSP(Multiplex Section Protection)

MSP(linear) is also called as APS(Automatic Protection Switching)NE-A NE-B

1+1Protection

1:1Protection

1:N Protection

TXRX

RX

RX

TX

TX

WORKING

PROTECTION

HIGH PRIORITY LINE WORKING

LOW PRIORITY LINE WORKING

TX

TX

RX

RX

WORKING

WORKING

PROTECTION