Quantum and Evolution Series Installation and Operating Handbook
8-61
Q. Can I remotely control the
Paired Carrier
function?
A. Yes,
Paired Carrier
can be controlled remotely in the same way as any other modem
function via RS232, RS485, web browser or SNMP.
Q. Can I add
Paired Carrier
into an existing network?
A. Yes, bandwidth savings can be made with existing networks, but a link budget analysis
must be made to assess the suitability and benefits.
Q. Surely there is some disadvantage in using
Paired Carrier
?
A.
Paired Carrier
has a minimal impact on Eb/No for a desired BER but typically between
0.15dB and 0.5dB extra carrier power is required to be transmitted on satellite to
overcome the imperfections in the signal cancellation process. Also, of course, power is
needed for the second carrier.
Q. What prerequisites exist for using
Paired Carrier
?
A. It requires a full-duplex link where you must be able to receive your own uplink signal
off satellite. It works only with ‘bent-pipe’ transponders where there is no
demodulation/remodulation or cross-strapping between transponders. The transponder
must do no more than filter, frequency convert and amplify the signal.
Q. Is it difficult and time consuming to install and set up
Paired Carrier
?
A. No. The operator sets the satellite delay or alternatively the modem and satellite
positions to allow the satellite signal to be acquired. A few other parameters specific to
Paired Carrier
need to be set up. Set up takes less than 5 minutes in total.
Q. Is
Paired Carrier
available as a field upgrade?
A. Yes. All Quantum modems can be field upgraded to support
Paired Carrier
operation
to the desired cancellation bandwidth.