Ericsson LBI-39224 manual T1/E1 Digital Site Configuration

LBI-39224

T1/E1 Digital Site Configuration

Networked Systems Considerations

Any system nodes that are connected using T1/E1 Interfaces must remain frequency locked at all times. The T1/E1 Interface design allows for total network synchronization by offering the following CEC/IMC Configuration options. Each of these options are selectable by configuration of both the Clock Boards and the T1/E1 Interface Cards.

1.Master - Redundant Clock Circuits generated by the Clock Board in a FREE RUN mode. This allows any CEC/IMC to become the master source of Network timing. All nodes connected to this CEC/IMC will be in the slave mode. This mode is established by setting the Clock Board DIP switches to "Master" mode and all the T1/E1 Interface Cards' Slave Clock option to "NONE."

2.T1/E1 Slave - Redundant Clock Circuits generated by the Clock Board synchronized to 1 (or 2 with redundancy) T1/E1 Interface into the CEC/IMC. The CEC/IMC can be slaved to an external node that is connected through a T1/E1 link, and no additional timing source is needed. Timing from the T1/E1 line is passed to the Clock Board from the T1/E1 Interface Cards through a redundant set of synchronization clocks named Slave A and Slave B. Each T1/E1 Interface Card can provide Slave A, B or A&B. This mode is established by setting the Clock Board DIP switches to "Slave to 8kHz" and 1 T1/E1 Interface Card Slave Clock option set to "SLAVE A," with another set to "SLAVE B" for redundancy, or 1 T1/E1 Interface Card set to "SLAVE A&B" for no redundancy.

3.Slave to external 1.544 MHz - Redundant Clock Circuits generated by the Clock Board synchronized to 1 (or 2 with redundancy) external clock source. Any CEC/IMC can be synchronized to the timing output from a T1/E1 multiplexer, microwave radio, fiber network, etc. Connect the external timing source to both Clock Boards in the CEC/IMC for redundancy. This mode is established by setting the Clock Board DIP switches to "Slave to Ext. 1544 kHz" and all T1/E1 Interface Cards' Slave Clock option to "NONE."

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