P300H
P300 Series Modem Installation and Operating Handbook
Page 29
[Drop /Insert Feature]
Bearer Types
T1-D4, T1-ESF, and G.732.
Timeslot Selection
Independent selection of arbitrary timeslots for both Drop and Insert.
Bearer Generation
The terrestrial bearer may be looped through the Drop mux then Insert
mux, or terminated after the Drop mux and a new blank bearer
generated by the Insert mux. The bearer generated within the Insert
mux provides full multiframe and CRC support and may be generated
from the Tx Clock, Station Reference, Satellite Clock or Internal
reference.
Bearer Backup
In the event that the Insert mux bearer clock is lost, or AIS is supplied,
then the Insert mux will switch temporarily to bearer generation mode
in order to preserve the receive traffic. The backup bearer may be
generated from the Station Reference, Satellite Clock or Internal
reference.
Terrestrial CRC
Fully supported, with front panel display of terrestrial error rate based
on CRC (T1-ESF and G.732) or Frame Alignment Word errors (all
bearer types)
Timeslot ID Maintenance
The IBS/SMS or Closed Net plus ESC overhead maintains the identity
of individual D/I timeslots for N=1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24,
30 (see Extended D/I Feature below).
[Extended Drop/ Insert Feature]
Timeslot Re-ordering
Selected timeslots may be independently re-ordered on both Tx and
Rx paths.
Timeslot ID Maintenance
The IBS/SMS or Closed Net plus ESC overhead is extended to
maintain the identity of individual D/I timeslots for
all values
of N from 1
to 31, including the previously unavailable values N=7, 9, 11, 13, 14,
17 - 19, 21 - 23, 25-29, and 31.
Multi-destinational working
All or only a subset of the received data may be inserted into the
terrestrial bearer on the receive path for multi-destinational working.
Signalling
Both Channel Associated Signalling (CAS), and Robbed Bit Signalling
(RBS) are fully supported:
For
E1
G.732 Drop/Insert, CAS signalling is extracted from
terrestrial TS16 and carried over the satellite in IBS/SMS TS16 and
TS48 before re-inserting into the distant terrestrial TS16
For
T1-D4
and
T1-ESF
RBS the IBS or Closed Net plus ESC
overheads maintain the identity of the in band signalling, and it is
re-inserted into the terrestrial multiframe in the correct positions to
maintain the RBS.
