LinkStar: Space Segment

The space segment for a LinkStar network is of the bent-pipe type, such as Ku-band and C-band transponders of any global or regional satellite system. The LinkStar space segment is made up of one or more broadband outbound links, and many inbound links.

Outbound Link

The outbound link - from the hub to the remotes - is a multi-megabit data stream that is compliant with the DVB-MPE format. Information is sent from the hub terminal to the large number of remotes over this common link, with the following operating parameters:

Transmission Rate: Selectable rate (5 to 42.5 Msps)
Format: Continuous (TDM)
Modulation/FEC: ETSI-compliant (EN-301210) modulation and FEC (forward error correction) formats:
(a) QPSK with concatenated coding (inner convolutional FEC and outer RS), or
(b) 8-PSK with concatenated coding (inner Pragmatic Trellis Coded Modulation (PTCM), outer RS)
Transport Stream: MPEG-2 and DVB Multi-Protocol Encapsulation (DVB-MPE) format for IP data.

Inbound Link

In the inbound direction - from the remotes to the hub - the LinkStar network uses multiple links that are shared by associated groups of remote terminals. The inbound link is compliant with a subset of the DVB-RCS standard, with the following operating parameters:

Transmission Rate: Selectable rate (156.2, 312.5, 625 or 1250 ksym/s)
Format: Demand assigned bursts over multiple TDMA (Time Division Multiple Access) carriers
Modulation/FEC: Burst QPSK with Rate 2/3 Turbo Code FEC.
TCP Acceleration: TCP "spoofing" support.