Paradise Datacom Quantum, Инструкция по установке и эксплуатации

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Quantum and Evolution Series Installation and Operating Handbook
8-22
Each feature is given an acronym by which it is referred to on the user interfaces, etc. A
full list of modem SAF features available at the time of publication of this handbook is
shown in Section 6.3 (please contact your supplier or Paradise Datacom Sales for the
most up to date list). Please check with your supplier or Paradise Datacom whether a
particular feature requires a hardware option card to be fitted.
The SAF function keeps the initial cost of a modem to the minimum and allows simple
field upgrading at a later date, as required.
8.6 Software Upgrading
It is possible to update the software and firmware within the modem via the Remote M&C
Ethernet connection web user interface (upgrades via the serial M&C port are not
supported). See the section on Remote Software Upgrade within the Web User Interface
description.
8.7 Partial Insert and Multi-destinational Working
Partial Insert is only available if the Extended D/I feature is available. In a typical scenario,
there may be a 2048kbps incoming carrier, containing say 8 timeslots (512kbps) for this
destination. When set to
Normal
the full 2048kbps has to be received and passed to the
terrestrial. When set to
Partial
, only the 8 timeslots for this destination are selected and
inserted onto the insert mux bearer avoiding overwriting
all the data
on the bearer.
This technique can be applied to lower rate carriers also. For example, suppose four
destinations require mesh connectivity at 384kbps (6 x 64kbps, although asymmetric
operation up to any rate is possible). Each site has a modulator transmitting 1152kbps (3 x
384kbps), and three demodulators receiving the 384kbps from the other sites. The satellite
bandwidth requirement is for four 1152kbps carriers, not twelve 384kbps carriers (ie the
same aggregate rate, but possibly lower overall bandwidth when carrier spacing is taken
into consideration):
∋
A single T1 or E1 bearer is looped through three modems, one operating as Tx/Rx,
and two others in Rx only. In this example we will assume it is a T1 PCM bearer.
∋
The Tx data for all destinations arrives at the single Tx modem in each site on the T1
bearer in 18 timeslots. Note that the ability to re-order the Tx and Rx timeslots means
the data can be in
any
timeslots and in any order.
∋
Each of the four sites transmits a 1152kbps (3 x 384kbps carrier) and all four
destination sites receive the three carriers from the other destinations.
∋
At each site all three modems are configured for Rx Partial Insert, and the data for all
but this site is discarded leaving a 384kbps to be inserted onto the looped T1 bearer by
each Rx modem. In this way the data from each site for this destination can be re-
inserted into the original timeslot from which the Tx data was dropped.
Without
Partial Insert if each Rx modem inserts
all the received data
(18 timeslots) onto the
T1 bearer, then the second Rx modem could just about insert its 18 timeslots without