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V100 Versatile Multiplexer Technical Manual Version 2.2
Page 10 of 231
1.2
Capabilities
1.2.1
Analogue Voice/FAX
A wide range of ITU-standard algorithms may be individually selected according to
bandwidth and quality requirements, with bit rates from 5.3Kbps up to 64Kbps. All
channels support Group 3 FAX at 2400-14400bps, V.22, V.22bis and V.32bis modem
relay and provide G.168 echo cancellation. Bandwidth may be permanently assigned or
used on-demand to optimise link use, when it may be redistributed among data
channels using the Dynamic Bandwidth Allocation feature. Comfort Tone Generation and input/output gain
adjustment allow the voice channels to be optimised for all situations.
The analogue voice cards are available in 2-, 4- or 8-channel form and provide FXO, FXS and 4-wire E&M
(Tie-line) interfaces for connection to private analogue circuits. DTMF, MF and E&M signalling standards
are supported.
1.2.2
Secure Voice Relay
With the addition of the optional Secure Voice Relay card, the analogue voice/FAX
card is able to support data relays for STU-IIb and STU-III secure telephone units.
This demodulates the encrypted traffic and passes it as data to the remote unit,
where it is remodulated for the secure telephone at that end. The key benefit is that
the encrypted traffic can then pass through a low-speed compressed voice channel, thereby saving
valuable bandwidth. At no time is the sensitive traffic decrypted.
1.2.3
Data
The V100 chassis has two dedicated data ports in the chassis and further ports are
available by adding 4-channel option cards, to yield a maximum of ten channels per
chassis. Any port may be synchronous or asynchronous, at speeds up to 2Mbps and
may be used as an aggregate or a tributary. It is possible to assign any tributary
channel to be multiplexed over any aggregate channel, or to pass via the HSC to a port
on any other unit, subject to bandwidth restrictions.
Ports configured as aggregates may be operated in fixed-carrier mode (for example over VSAT SCPC
links) or in switched-carrier mode (for example in DAMA, Inmarsat-B or SCADA networks).
Data ports are implemented on 15-way ‘D’-type connectors and support a wide range of software–
selectable interface standards. Each port has two independent Phase-locked Loops (PLLs), which permit
the RX and/or TX clock to be locked to any other port in the system, thus permitting onward-linking and
asymmetric bandwidth operation if required.