User's Manual

Table Of Contents
Installation and Administration
c05_ikon.fm
Synchronisation over air concept
A31003-C1010-S100-2-7620, 08/2010
62 HiPath Cordless IP, Service Manual
5.2.1 Overview of reserved networks
192.168.1.1 and 192.168.2.1 are used for factory defaults of BSIP Only and
BSIP IWU
192.168.123.x (.222) for BSIP Local on BSIP Iwu and (.111) corresponding
host ip
169.254.222.x (CSP) and 192.168.123.x (MSP) for internal LINUX communi-
cation
5.3 Synchronisation over air concept
In contrast to a line based synchronisation mechanisms (or a network based
one), synchronisation via air requires special requirements.
Synchronisation signal
Both synchronisation partners are syncing by air. This means that the
synchronisation signal received by the synchronisation client from the
synchronisation master has to have a minimum signal strength. The minimum
signal strength for the synchronisation signal is -85 dB.
Synchronization sequence
For the operation of several synchronized Base Stations the synchronization
sequence shall be configured as a "chain", (chain topology) i.e. the second
Base Station synchronizes to the first, the third Base Station to the second,
the fourth to the third and so on.
If all Base Stations synchronize to one single "Master" Base Station (in a star
topology) a much longer period of time will be needed for the reconstruction
of the system wide synchronization, because of the "Burst" behavior.
In addition to that the distance of a "Sync Slave" to the topmost "Sync Master"
in the synchronization chain shall not be more than 2 hops (Base Stations)
else the "Slip" will be to big and if a Base Station looses synchronization it will
only be (automatically) resynchronized when there are no longer active calls
at this Base Station.
For some topologies it is possible to mix the star topology with the chain
topology.
Avoid using a chain topology which is physically arranged as a circle. In such
a scenario, the drift between the first and the last base station maybe too
large to ensure proper handover between these two basestations.