Fleet managers and shipowners can choose VSAT services that provide coverage shared between the fleet or are dedicated to individual vessels. The service they decide to take will depend on their bandwidth requirements for multiple vessels in a fleet, or for specific ships.
SCPC - Single Channel per Carrier
Single channel per carrier (SCPC) technology uses a dedicated carrier to each remote VSAT to receive information from a central site, and another dedicated carrier for each VSAT to transmit information back to that hub. SCPC was the first VSAT technology offered to the maritime and offshore sectors, enabling ship operators to provide high bandwidth to individual vessels.
TDMA - Time Division Multiple Access
Alternatively, shipowners can choose a time division multiple access (TDMA) network, where bandwidth is shared and segmented across several vessels. TDMA technology involves a single high speed time division multiplexing carrier transmitted from the central hub to the satellite, from which many VSATs can receive information in a shared network. To transmit data back in a TDMA network, the terminals are synchronised and transmit information in a burst mode within a series of short scheduled timeslots. Suppliers of TDMA services offer always-on high speed and flat rate VSAT connectivity, but with higher network contention ratios because the network is shared.