XRT75VL00D datasheet(76/92 Pages) EXAR

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XRT75VL00D

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

REV. 1.0.3

9.5.5

87-3 Pattern

Figure 51 presents an illustration of the "87-3 Continuous Pattern" Pointer Adjustment Scenario per Telcordia

GR-253-CORE.

Telcordia GR-253-CORE defines an "87-3 Continuous" Pointer Adjustment pattern, as a repeating sequence of

90 pointer adjustment events. Within this 90 pointer adjustment event, 87 pointer adjustments are actually

executed. The remaining 3 pointer adjustments are never executed. The spacing between individual pointer

adjustment events (within this scenario) can range from 7.5ms to 10seconds.

Telcordia GR-253-CORE mandates that the Intrinsic Jitter, within the DS3 signal that is de-mapped from a

SONET signal, which is experiencing the "87-3 Continuous" pattern of Pointer Adjustments, must not exceed

1.0UI-pp.

9.5.6

87-3 Add

Figure 52 presents an illustration of the "87-3 Add Pattern" Pointer Adjustment Scenario per Telcordia GR-253-

CORE.

FIGURE 51. AN ILLUSTRATION OF THE 87-3 CONTINUOUS POINTER ADJUSTMENT PATTERN

Initialization

Measurement Period

Repeating 87-3 Pattern (see below)

Pointer Adjustment Events

87-3 Pattern

87 Pointer Adjustment Events

No Pointer

Adjustments

NOTE: T ranges from 34ms to 10s (Req)

T ranges from 7.5ms to 34ms (Obj)

XRT75VL00D 데이터시트(PDF) 76 Page - Exar Corporation