User Manual
Table Of Contents
- 1. Getting started
- 2. Introduction
- 3. Preparation
- 4. About the terminal
- 5. Mounting and installing the terminal
- 6. Connecting to the terminal
- 7. Managing the terminal
- 8. Configuring the terminal
- 9. Configuring the traffic interfaces
- 10. Cross Connections
- Embedded cross connect switch
- The Cross Connections application
- The Cross Connections system requirements
- Installing the Cross Connections application
- Opening the Cross Connections application
- The Cross Connections page
- Setting the terminal's address
- Management and user ethernet capacity
- Setting card types
- Getting cross connection configuration from the terminals
- Creating cross connections
- Sending cross connection configuration to the terminals
- Saving cross connection configurations
- Using existing cross connection configurations
- Printing the cross connection configuration
- Deleting cross connections
- Configuring the traffic cross connections
- Cross connection example
- Symmetrical Connection Wizard
- 11. Protected terminals
- 12. In-service commissioning
- What you will need
- Checking the antenna polarization
- Visually aligning antennas
- Accurately aligning the antennas
- Synchronizing the terminals
- Checking performance
- Checking the receive input level
- Checking the fade margin
- Checking long-term BER
- Bit Error Rate tests
- Additional tests
- Checking the link performance
- Viewing a summary of the link performance
- What you will need
- 13. Maintenance
- 14. Troubleshooting
- 15. Interface connections
- 16. Alarm types and sources
- 17. Country specific settings
- 18. Specifications
- Ethernet interface
- QJET Quad E1 / T1 interface
- Q4EM Quad 4 wire E&M interface
- DFXO Dual foreign exchange office interface
- DFXS Dual foreign exchange subscriber interface
- QV24 Quad V.24 asynchronous data interface
- HSS Single high speed synchronous data interface
- External alarm interfaces
- Auxiliary interfaces
- AC Power supply
- DC Power supply
- Power consumption
- MHSB protection
- Ethernet interface
- 19. Product end of life
- 20. Abbreviations
- 21. Acknowledgments and licensing
- 22. Commissioning Forms
- 23. Index

Configuring the terminal | 63
Modem Performance Settings
Select Local or Remote > Performance > Summary and Quick Links of Modem Performance Settings.
There are two Modem Performance Settings, Modem QPSK Coding and Modem Interleaver Mode.
Modem QPSK Coding
When the Modulation type is set to QPSK, the default QPSK Coding setting is ‘Non-Gray Coded’ but
the QPSK Coding can use ‘Gray Coded’ for interoperability with older hardware.
Modem Interleaver Mode
The Modem Interleaver improves modem bit error rate but increases the end to end link delay so the
Modem Interleaver should be enabled where a low bit error rate is required and disabled where a low
end to end link delay is required.
The ‘Default’ Modem Interleaver Mode setting is on for channel sizes of 250 kHz and greater and off
for channel sizes of 200 kHz and less. The specification of End to End Link Delay for both interleaver
on and off is given in “
System performance specifications” on page 238.
When you change the Modem Interleaver Mode in an operational terminal, traffic across the link will be
interrupted
Both terminals must be set to the same Modem Interleaver Mode.