2. Functional Operation

7/30/2019 2. Functional Operation

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FUNCTIONAL OPERATION 1

Pasolink+ XPIC Training Course.

FUNCTIONAL OPERATION

CHAPTER 02




1. System Configuration (1/3)












2. General Signal Flow for 11-38 GHz OMT (1+0) (1/4)




2. General Signal Flow for 6-38 GHz feeder connection (1+0) (2/4)




2. General Signal Flow for 11-38 GHz using OMT (1+1) (3/4)




2. General Signal Flow for 6-38 GHz using hybrid (1+1) (4/4)




3. IDU Block Diagram for (1+0) (1/2)

*1 Optional.

*2 One of 150M INTFC, OPT INTFC or 10/100BASE-T

INTFC may be used.




3. IDU Block Diagram for (1+1) (2/2)

*1 Optional.

*2 One of 150M INTFC, OPT INTFC or 10/100BASE-T

INTFC may be used.




4. ODU Block Diagram




5. Alarm and Control (1/17)

The functions of the alarm and control circuit are as follows:

1. Alarm indication and reporting.

2. Performance monitoring/metering data reporting.

3. Automatic laser shutdown control (OPT INTFC module).

4. Automatic transmitter power control.

5. Loopback control.

6. Far-end link down control.

7. MS-AIS generation.

8. XPIC reset control.

9. Network Management (Optional).

10. Optional Interface Card.





1. Alarm and Control Block Diagram (for 1+0)





1. Alarm and Control Block Diagram (for 1+1)





5.1 Alarm Indication and Reporting





5.1 Alarm Indication and Reporting(Cont.)

Note: In 1 + 0 system, ALM LEDs are applied only No. 1 side.





5.2 Performance Monitoring/Metering Data Reporting

1. To monitor the transmission quality on the STM-1 transmission, the equipment is provided with the

performance monitoring and the metering functions.

2. The CTRL module, polls the different modules and gathers PM/Metering information.

3. A “invalid” displayed in the PM results screen indicates that the value is illegal.

4. When the equipment clock setting is changed or the power is turned on/off, the PM value is judged to be

invalid.

5. A “MAINT” is displayed if the PM results are obtained while the equipment is in maintenance mode.6. The monitoring items are as follows:

1. Out of Frame Second (OFS)

2. Background Block Error (BBE)

3. Error Seconds (ES)

4. Severely Error Seconds (SES)

5. Unavailable Second (UAS)

6. TX POWER7. RX LEVEL

8. ODU PS MON

9. Bit Error Rate (BER)





5.3 ALS (OPT INTFC Module).

1. The IDU is provided with the automatic laser shutdown (ALS) function that can be enabled or

disabled.

1. If the ALS function is enabled, the laser output is periodically turned ON and OFF when the optical

cable carrying the STM-1 signal is disconnected inadvertently, or intentionally during maintenance.

1. If the ALS function is disabled, the laser output is always ON even if the optical cable is

disconnected.

ALS System Functional Block Diagram





The automatic transmit power control (ATPC) function automatically

varies the TX output power according to path conditions. In the 6 to 38

GHz band, fading exerts heavy influences on propagation, causing thereceive signal level at the opposite station to vary. The ATPC function

operates by controlling the transmit output power of the opposite station

according to the variation of the received signal level at the local station.

ATPC provides the following advantages:

•• Improvement in up fading characteristics

•• Improvement in residual BER characteristics

•• Reduction of interference to intra system

•• Reduction of interference to inter system

ATPC improves the BER characteristics under adverse changes in

climatic conditions and reduces the possibility of interference. To

implement ATPC, the receiving level (RX IN LEV) is detected by the

receiver (RX) and passed on to the CPU in the CTRL circuit of the

MODEM module. The CPU then determines whether the transmit output

power needs to be controlled. This is based on the transmit output

power, the minimum and maximum values of the output control range,and the receiving threshold level that were previously specified using the

LCT or PNMT.

A control signal (POWER CONT), whose function is to maintain the RX

signal level by lowering or raising the TX output power of the opposite

station, is generated by the MODEM module through the CPU circuit. Thiscontrol signal is based on the result of comparison between the current

receiver input level and the preset receiving threshold level. Using RFCOH

bits, this control signal is sent to the opposite station to control its transmit

output power.

At the opposite station, this control signal is detected by the MODEM

module. The MODEM module, in accordance with this control signal,

produces a control that will either raise, lower or maintain the current TX

output power.

The ATPC Control System of Pasolink Mx transmits the information on the

receiving level to the opposite station and controls the transmission level of

its own station in accordance with the receiving level of the opposite

station. Transmission level control can be used not only for setting the same

operation (ATPC-ATPC) between own station and opposite station but also

for operation in combination of stations with different operation (MTPC-

ATPC, ATPC-MTPC) between own station and opposite station. The

station set in MTPC mode is not controlled by the information from

opposite station but is fixed in its transmitting output level.

Even if the station is set in the MTPC mode, the opposite station is likely to

be set in the ATPC mode. Therefore, setting the RX Threshold (Receiving

threshold level) is required for controlling the transmission level of the

opposite station. Between the stations that are respectively set in the MTPC

mode, however, the setting is disabled.

5.4 Automatic Transmit Power Control (ATPC).





ATPC setting parameters:-

1- TX max. = Nominal – (0 ~ 10dB)2- TX min. = Nominal – (0 ~ 20dB)

3- ATPC RX threshold (Reference ) = -30 ~-70dB

- ATPC will start with the TX min. power

- When the RX level of the opposite site is decreased to be below the reference RX

- The ATPC Will start increasing the TX power up to TX max. in one dB steps until increasing the RX level

of the opposite site to be over the reference level

- The ATPC will maintain the RX level within 5 dB over the reference level

5.4 Automatic Transmit Power Control (ATPC) Cont.




ATPC hysteresis(provisioning)ATPC Rx Threshold

(provisioning)

Min Tx Lev(Provisioning)

Max. Tx Lev(Provisioning)

Tx Out

Low

High

Rx Lev

Fading

Fading

High

Low

ShallowDeep

ShallowDeep

The ATPC Control transmits the information

on the receiving level to the opposite station

and controls the transmission level of its own

station in accordance with the receiving level

of the opposite station.

The ATPC Control can be used in several

configurations:

ATPC - ATPC

MTPC - ATPC

ATPC - MTPC


5.4 Automatic Transmit Power Control (ATPC) Cont.





5.5 XPIC Reset Control.

The XPIC RESET control is performed when the system is in following Conditions:-

1. Frame Synchronization is lost (FASYNC) at the DEM module in the Co-pol. channel.

2. At the DEM module in the Co-pol. channel, IF signal from X-pol. channel is lost.

3. The system is controlled in IF loopback (IF-LB) condition with the LCT, PNMS or PNMT.

4. The XPIC RESET control is executed from the LCT, PNMS or PNMT.

5. The XPIC RESET control is applied from the DEM module in the Xpol. channel.

XPIC Rest Remote Control





5.6 Loop Back Control.

The loopback function is provided for checking the system quality during maintenance and/or to quickly isolate a fault location.

The control is performed by the LCT, the PNMT or the PNMS.

Provided here is the control of the:-

A- STM-1 Near End Loop Back.

B- STM-1 Far End Loop Back.

C- IF Loop Back.

Loop Back Location





5.7 Far End Link Down Control.

1. Far-end link down control provides two kinds of functions for 10/100BASE-T INTFC.

2. One is to automatically stop the output from the LAN port to alert the equipment connected with the LAN port whenthe system has been disconnected by the fault in the radio section.

3. The other is to transmit the information for cutting the link interconnected with the LAN port in the opposite station

when the link between the LAN port and equipment is faulty.

4. This function can be selected by setting “Provisioning” on LCT to “Enable” or “Disable” .

Far End Link down Control





5.8 MS-AIS Generation.

When any fault occurs in the Pasolink+ equipment or radio section, or when STM-1 input signal

disappears. The function of MS-AIS Generation causes the STM-1 output signal from Pasolink+

equipment to be stopped and/or non-frame signal (all “1”) to be output, to detect the fault in the

MUX equipment of the opposite station.

This function can be selected by setting “Provisioning” on LCT to “Enable” or “Disable” . Normally,

this function is set to “Enable”. If this function is set to “Disable”, the function of MS-AIS

Generation is stopped.

MS-AIS Generation





5.9 Network Management System.

The pasolink network management system (PNMS) is connected to the PNMS V.11/LAN connector of

the IDU located at the designated maintenance center while the pasolink network management

terminal (PNMT) is connected to the PNMT connector on the IDU of remote stations.

The PNMT/PNMS provides real-time monitoring and control of the microwave link status and its

associated Pasolink equipment. Status information from and control signals to remote stations

are transmitted using RFCOH.

Note:

This DSC channel is multiplexed on the main signal for subsequent transmission to the opposite

station. If the IF loopback is executed the DSC channel of the station under maintenance willalso be looped back, thereby making it impossible to monitor or control the opposite and the

subsequent stations.

Network Management System.





5.10 Optional Interface Card..

The LAN Card and Cluster Alarm Interface Card are provided as optional Sub-interface cards. By

mounting the LAN Card in the IDU of the system, an auxiliary transmission channel can be

provided.

LAN Card

The LAN Card can provide an auxiliary transmission channel for an LAN signal using the following

overhead channel:

128 QAM system :- 64K, DSC or RSOH (E1/F1).

Assignment of LAN Card is selected from the “OH Assignment” menu under Provisioning.

The LAN Card has a bridge function, and it can store 10,000 Media Access Control (MAC) address,

which is updated in every 5 minutes.

ALARM INTERFACE

The Alarm Interface Card allows extension of two cluster alarm signals for internal/external alarms to

the remote station using 64K,

DSC or RSOH (E1/F1) overhead channel.

Assignment of Alarm Interface Card is selected from the “OH Assignment” menu under Provisioning.





5.10 Optional Interface Card (Cont.)

Example of Use Optional LAN Card.




Protection switching in Pasolink (1+1 ) system has several switching priorities.

Priority 1: Remote switching Control

TX switching

Switching is initiated from external equipment (LCT/PNMT)Priority 2: Automatic switching control

For any alarm in the online equipment, traffic will be switched to the standby equipment automatically.

TX and RX switchover are performed independently.

In the (1+1)HS system transmit

switching is carried out by setting

the standby ODU out put to off

by Muting it. The data signal istransmitted in parallel to both

CH1 and CH2.

RX switching

When the Online RX CH fails,

the ALM CONT circuit in the

SW Board initiate a RX SW

Control signal to switch to thestandby CH provided it is in

normal operating condition.

6. PROTECTION SWITCHING

When Hitless switch is used make sure that the difference between the two IF cable lengths are less than 50 meters

TX PWR ALM

TX LO APC ALM

ODU IF INPUT ALM

MOD ALM

TX DPU ALM

CPU ALM

RX LEV ALM

RX LO APC ALM

DEM ALM

FSYNC ALM

HIGH BER ALM

OPR ALM

CPU ALM

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2. Functional Operation