XRT75VL00D datasheet(74/92 Pages) EXAR

74 / 92 page

XRT75VL00D

E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER

REV. 1.0.3

NOTE: All of these intrinsic jitter measurements are to be performed using a band-pass filter of 10Hz to 400kHz.

Each of the scenarios presented in Table 18, are briefly described below.

9.5.1

DS3 De-Mapping Jitter

DS3 De-Mapping Jitter is the amount of Intrinsic Jitter that will be measured within the "Line" or "Facility-side"

DS3 signal, (after it has been de-mapped from a SONET signal) without the occurrence of "Pointer

Adjustments" within the SONET signal.

Telcordia GR-253-CORE requires that the "DS3 De-Mapping" Jitter be less than 0.4UI-pp, when measured

over all possible combinations of DS3 and STS-1 frequency offsets.

9.5.2

Single Pointer Adjustment

Telcordia GR-253-CORE states that if each pointer adjustment (within a continuous stream of pointer

adjustments) is separated from each other by a period of 30 seconds, or more; then they are sufficiently

isolated to be considered "Single-Pointer Adjustments".

Figure 48 presents an illustration of the "Single Pointer Adjustment" Scenario.

Telcordia GR-253-CORE states that the Intrinsic Jitter that is measured (within the DS3 signal) that is

ultimately de-mapped from a SONET signal that is experiencing "Single-Pointer Adjustment" events, must

NOT exceed the value 0.3UI-pp + Ao.

NOTES:

Ao is the amount of Intrinsic Jitter that was measured during the "De-Mapping" Jitter portion of this test.

Testing must be performed for both Incrementing and Decrementing Pointer Adjustments.

9.5.3

Pointer Burst

Figure 49 presents an illustration of the "Pointer Burst" Pointer Adjustment Scenario per Telcordia GR-253-

CORE.

Continuous Add

1.3UI-pp

Includes effects of Jitter from Clock-Gapping, De-Map-

ping and Pointer Adjustments.

Continuous Cancel

1.3UI-pp

Includes effects of Jitter from Clock-Gapping, De-Map-

ping and Pointer Adjustments.

FIGURE 48. ILLUSTRATION OF SINGLE POINTER ADJUSTMENT SCENARIO

TABLE 18: SUMMARY OF "CATEGORY I INTRINSIC JITTER REQUIREMENT PER TELCORDIA GR-253-CORE, FOR DS3

APPLICATIONS

SCENARIO

DESCRIPTION

SCENARIO

NUMBER

TELCORDIA GR-253-CORE

CATEGORY I INTRINSIC

JITTER REQUIREMENTS

COMMENTS

Initialization

Cool Down

Measurement Period

>30s

Pointer Adjustment Events

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