Aastra X Series, Руководство по установке и внедрению

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Page 8-147 10/2008 AMT/PTD/TR/0020/2/7/EN
8.2 Distributing DECT synchronisation to the base stations
8.2.1 Distribution by M bit
Here the synchronisation signal is distributed to the base stations by the M bit of the S0 frame
from the DECT interface card (LD4/LD4N cards for the M6501 L/R/RM IP PBX (F1), LD4/LD4NX
(LD4N or LD4X mode) for NeXspan S/L/D (F6), LDT card for NeXspan 50 (F4) equipped with
FPHBG2/CSI and LDT card for NeXspan 500 (F4) fitted with FPS/CSI.
In an F2 or F4 (equipped with FPHBG/FPS, CSH/CSI, LDS and/or LDT), a master LDS card (or
LDT card in an F4) synchronizes the slave LDS cards (and/or LDT card in an F4) through wiring
on the distribution frame. In this mode, multisite handover in an F2 and/or F4 network is possible
provided that bit synchronisation (2.048 Mhz clock) is carried out (by inter-site link).
8.2.2 Distribution by 3rd pair
The base stations of the different sites must be synchronised by wiring a third pair in the
following circumstances:
• if the installation has several PBXs not equipped with DECT synchronization ports
• configuration using integrated S0 accesses of the NeXspan S first-generation CPU card.
In this case, the synchronisation signal is distributed by a 3rd pair from a master base station to
the slave base stations. Between one and four slave base stations may be connected to the
master base station. If there are more than 5 base stations, a repeater is required to distribute
the clock synchronisation generated by the master base station.
Figure 7-1: Distribution by 3rd pair
Master RFP Slave RFP Repeater
third pair