Aastra X Series, Installation And Implementation Manual

Page: 146 / 217

AMT/PTD/TR/0020/2/7/EN 10/2008 Page 8-146
Chapter 8- Multi-site synchronisation
(before R5.1)
Note:
The use of the DECT system in a heterogeneous environment (R4.2 and/or earlier) with
Aastra X series R5.1 sites is not handled in this chapter.
8.1 Principle
8.1.1 Contiguous multi-site configuration
In a contiguous multi-site configuration, the base stations of site 1 can "hand over" to base
stations of site 2. The base stations of the different sites must therefore be synchronised with a
single 800 ms clock.
If the configuration allows it, it is preferable to synchronise the remote site(s) via the inter-site
link(s) and NOT via the external accesses (France Telecom) to obtain 2.048 MHz bit
synchronisation.
For F4 multi-site configurations with a link (T2 or QSIG)
• For a device equipped with an FPHBG back plane and CSH, LDS and/or LDT cards: with two
inter-site links, when the USB is duplicated, the clock of the first link synchronises the first
card of the USB (CSH, CUH or CUS card) of the slave PBX, and the clock of the second inter-
site link synchronises the second card of the USB of the slave PBX.
If the USB is not duplicated (single CSH, CSI, CUH or CUS card), the clock of the second
inter-site link must be connected to the same CSH, CSI, CUH or CUS card as the clock of the
first link.
• For a device equipped with an FPHBG2/FPS back plane and CSI, LDT card: the BCSI card,
connected to the RHMIC/RHMIC2 card, synchronises the USB cards in NeXspan 50/500 to
provide a synchronous multisite DECT network offering DECT mobiles the inter-site handover
function. The BCSI board sends or receives the DECT synchronization and the 2.048 MHz bit
synchronization to/from another PBX; it determines the compensation to make on the DECT
clock received according to the distance of the transmitting PBX and retransmits the clocks
received to the CSI card.
8.1.2 Non-contiguous multi-site configuration
In a non-contiguous multi-site configuration there is no overlap between the radio coverage of
the different sites. It is not therefore necessary to synchronise the base stations of the different
sites, nor the sites themselves.
Note:
Before setting up a DECT multi-site network, particularly if the network uses multiplexers
or modems in the inter-site links, contact the manufacturer's pre-sale services.