User's Manual

Table Of Contents

24 LEDR Series I/O Guide MDS 05-3627A01, Rev. D

3.8 Transmit Clock Selection (Subrate Radios Only)

For a subrate radio, transmit clock arrangement must be set by the user.

Clocking arrangements for fullrate radios is automatically handled by

the LEDR radios.

It is essential that there be only one master clock in a subrate radio net-

work. The master clock can originate from the radio or from the Cus-

tomer Premises Equipment (CPE).

LEDR radios are capable of several different clocking modes. Refer to

Figure 14 and Figure 24 for typical system clocking arrangements.

Refer to the CC

screen description on Page 35 for setting the

radio transmit clocking from the front panel. Refer to the

clkmode

description on Page 55 for setting the radio transmit clocking mode from

the front panel

CONSOLE Port.

NOTE: When customer premises equipment (CPE) is operated in

looped clock mode, it is recommended that the radio not be set

to line clock mode. To do so may cause the transmitting

radio’s PLL to be pulled out-of-lock, especially when oper-

ating at 4E1 data rates.

Table 11. Fullrate Bandwidth vs. Modem Selection Code

Radio

Bandwidth

Configuratio

n Code

Data

Rate(s) Modulation

500 kHz C7 E1 32-QAM

1000 kHz B7 E1 16-QAM

C7 E1 32-QAM

C8 2E1 32-QAM

2000 kHz A7 E1 QPSK

B7 E1 16-QAM

B8 2E1 16-QAM

C8 2E1 32-QAM

C10 4E1 32-QAM