6/1531-ANF 901 14 Uen F1 2013-11-29
15
P
REPARATIONS
Figure 4: A synchronization ring is needed between the first board in
all media gateways (the rest of the boards in mgw get sync
from backplane) to achieve external hand over between
those base stations which are connected to different boards.
Figure 5: A synchronization ring is not needed between the boards
when there is no radio coverage between them.
server 1
server 2
mgw 2B
mgw 2A
mgw 1B
mgw 1A
Ring Synchronization
cabling
Base
station
Base
station
Base
station
Coverage area
Synch
ro
nizatio
n so
urce
/- 5 PP
M accuracy
(PSTN)
NTU
o
r
CPE
+/
- 2
5
PPM
Optional
Base
station
Base
station
Base
station
MGW B
Server 1
MGW A
MGW B
Server 2
MGW A
Ring Synchronization
cabling
Coverage area
Synch
roniza
tio
n source
Within
+/- 5 PPM
accurac
y
(PSTN)
Coverage area
ELU31
NTU o
r CPE
+/- 25 PPM
NTU or CPE
+/- 25
PPM
Optional
