System Description

WipLL System Description
4-10 of 4-10 Marconi Communications Ltd. MCIL -WIPLL-SDN_R2_00
4.2.5. Unsynchronized vs Synchronized Operation
(Not for North America only for ETSI countries).
In unsynchronized mode, BSRs use random frequency tables. As such signal
collision is quite possible leading to frequent retransmission. Using orthogonal
tables helps to reduce this to a limited extent.
In synchronized mode, all BSRs use the same frequency table. A signal received
from the BSDU restarts the table phase. Up to 4 BSDUs may be daisy chained
together, in which case each BSDU will be assigned as Sync Ring Id and the master
BSDU will be the one to send the restart signal.
The GPS is designed to synchronize across base stations. 1 GPS can support upto 4
co-located BSDUs. If only one of the BSDUs has a GPS, that BSDU will
automatically be assigned as the master. If each BSDU has its own GPS or if there
are no GPSs installed on any of the BSRs, WipLL will assign a master BSDU Id to a
Sync Ring Id.
Figure 4-3: Sync/Unsync BS Capacity Comparison