1.	Proposed revisions to Recommendation 0.9 (former Recommendation O.121)

MEASURING ARRANGEMENTS TO ASSESS THE DEGREE OF IMBALANCE ABOUT EARTH

Replace § 2.5 with the following:

"2.5	Input Longitudinal Interference Loss (ILIL)

The measurement of this parameter is applicable to receiving devices (e.g., amplifiers, level meters, etc.). ILIL is a measure (a ratio expressed in dB) of the sensitivity of a receiving device to longitudinal disturbances. It is measured as shown in Figure 5a and 5b/0.121. In principle, it is similar to the longitudinal conversion loss (LCL) measurement. However, since the measurement is performed internally (using a built-in indicating device) or at the output

of the item under test, not only the impedance balance at points a/b but also the effect of common-mode rejection is measured. (See § 4.4.1 of Recommendation G.117 [1].)"

Measurements in accordance with Figure 5b/0.121 are also applicable to devices which perform a signal conversion (e.g., VF/CF side of channel translating equipment, A/D side of PCM multiplex equipment, etc. See § 2, point f of Recommendation G.117). In this case the measurement at the output of the item under test requires an appropriate analyzer; namely a selective level meter for measurements at channel translators or a digital analyzer (see Recommendation 0.133) for measurements at PCM multiplexers. In the equation in Figure 5b/0.121 it is assumed that Vo is measured at a 0 dBr point. The quantity X, is the relative level at port a/b.

ii)	Replace § 2.7 with the following:

2.7	Output signal balance (OSB)

This measurement (a ratio expressed in dB) is applicable to signal outputs. OSB is a measure of unwanted longitudinal signals at the output of a device. It is measured as shown in Figure 7/0.121 (see § 4.3.1 of Recommendation G.117 [1]).

The signal source G shown in Figure 7/0.121 can be internal or external to the device under test. OSB measurements are also applicable to devices which perform a signal conversion (e.g., CF/VF side of channel translating equipment. D/A side of PCM multiplex equipment, etc. See § 2, point f of Recommendation G.117). In this case an appropriate external signal source, namely a signal generator for measurements at channel translators or a digital signal generator (see Recommendation 0.133) for measurements at PCM-multiplexers is required.