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ND
SatCom’s SkyWAN® MF-TDMA VSAT system to
enable maritime communication services for
construction and drilling shipsEnd customer
requirements
 Satellite
communication was the only option to link a leading
European oil producing company’s drilling and
construction fleet to its headquarters, to exchange
operational information and to provide onboard
personnel with private phone service. A suitable
VSAT platform focusing on the minimization and
reduction of communication cost in comparison to
existing Inmarsat services had to be designed and
implemented. Basic communication applications were
voice communication, file transfer and emails. The
end customer had a special requirement that a vessel
should have access to a world wide service with no
disruptions. In case a vessel left the coverage of
one beam and entered the coverage of another
satellite beam, the vessel needed to be able to
switch over and continue accessing the communication
service.
Based
on its SkyWAN® system using the latest MF-TDMA
DAMA technology, ND
SatCom provided a cost effective satellite network
solution. The required bandwidth per satellite
frequency channel could be exactly assigned per
network or station. Through the fully dynamic
bandwidth allocation scheme, space segment capacity
was automatically assigned to a ship requiring
transmission capacity.
Thus, ND
SatCom SkyWAN® reduced the overall bandwidth
consumption of the fleet
to a minimum, combined with high flexibility in
traffic allocation per station within a certain time
period, as well as supporting numerous applications.
Due to its low hub cost and integrated management
capabilities, very attractive small to medium size
star network solutions could be offered compared to
standard SCPC solutions.
In
addition, the following features with the resulting
benefits were supported:
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Combination of
different services such as voice, data and video
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Guaranteed
service quality for different service categories
such as voice, video, data
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Star, hybrid or
meshed topology depending on the network
requirements
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Bandwidth on
demand providing optimal bandwidth usage
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No single point
of failure due to master / back-up master
concept and redundancy
for every station as an option
The
Indoor Unit at an ND SatCom SkyWAN® station
comprises a satellite modem for
IP routing and FR switching capabilities. Together
with a stabilised antenna, the station is capable of
fulfilling all requirements for maritime
communication usage.
For TDMA
alignment, the Indoor Unit supports round trip time
auto adjustment, which is necessary to compensate
for timing differences which occur during ship
movement. Furthermore, every station has auto
acquisition of the timing range if a ship station is
switched off for a certain time and needs to
synchronise itself at another location. This
procedure can be accelerated using the ship’s GPS
system.
The
network provides worldwide coverage for all vessels
in operation in the Atlantic, Indian and Pacific
Oceans which are always linked to their headquarters
in Europe by a single hop. The whole network is
operated by the Italian satellite service provider
Telespazio who takes care of the control, management
and maintenance of the network. The
telecommunication service offered by Telespazio has
complete worldwide coverage by means of three
satellites (Atlantic, Indian and Pacific beams) with
C-band frequencies. The unique benefit of this
solution is that vessels are able to change from a
satellite beam to a different satellite beam without
any service disruption. This means that in case a
vessel leaves its “home” satellite
beam, it will automatically be taken over by the
next satellite beam and the communication link will
be preserved. Telespazio equipped 18 of the customer’s
vessels and delivered three two hub stations.
The
Telespazio teleport in Fucino (Italy) hosts the
network HUB/NMS and serves the Atlantic and Indian
regions. An Intelsat teleport serves the Pacific
region. This teleport is connected via a leased line
connection from California to Italy. Voice and data
from teleports are extended via terrestrial lines to
the end customer’s European headquarters. Each
vessel can support simultaneous multiple voice
channels and one IP data port. An FAD (Frame Relay
Multiplexer) combines both communication services
via a single IDU port. Currently, each vessel has a
sending data rate capacity of 300 kit/s. The
customer’s vessels are equipped with suitable
stabilized antenna systems. Transmitter sizes are
compact thanks to the huge teleport antennas. A big
crane vessel is equipped with two complete
transmission systems in the event that one antenna
receives no signal from the satellite when the
jackup rig is in the line of sight to the satellite.
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