What is GISS?

2.4 Broadband Internet access and L-band interactive services

The main directions of achieving an effective (competitive) solution to this problem are:

• use of multi-beam receiving and transmitting onboard antennas SC based on APAA, with the possibility of creating as many narrow beams as possible; implementation of programmed control of AESA beams adaptively depending on the number and location of active and passive (registered in the network) subscribers, taking into account the movement of spacecraft and subscribers, the need to transfer subscribers from one spacecraft to another (“handover”); implementation of various types of terrestrial ATs with different types of antennas: mobile personal ATs with omnidirectional or weakly directional antennas, mobile or stationary ATs with directional antennas based on AESA; the use of signal-code structures based on effective error-correcting codes, which ensure reliable transmission of information through channels with interference, as well as through channels with multipath propagation (fading); use of various types of modulations (symbolic signal “constellations”) within a single signal-code structure, including high-order modulations with the ability to assign a type of modulation to each subscriber and switch modulation types without failures in data transmission;
• organization within the framework of a single signal-code structure of frequency and time division of subscribers with the ability to flexibly change the band, frequency position, time position and duration of the transmission occupied by each subscriber;
• implementation of a time-frequency resource control system within each spacecraft and the system as a whole with adaptive assignment of time-frequency positions, type of modulation and coding to each subscriber, depending on the network congestion, interference conditions, AT type, subscriber priority and other factors.

Depending on the implemented signal-code structure for signal transmission, which can adaptively change on demand, taking into account the directional properties of the AESA of the user terminal (AT) and the directional service mode from the spacecraft, the information flow on the downlink in each of 36, 72 or 144 territorial collective service zones can range from 40 Mbps to 100 Mbps and at least hundreds of kbps on AT with an omnidirectional antenna.

The subscriber access speed to territorial networks on the uplink can be implemented within the range of 0.1 - 1.0 Mbps for subscriber terminals with a low-directional antenna (3 dB) and up to 5.0-10.0 Mbps for terminals with a small-sized AESA (13-15 dB), providing tracking of the current position of the spacecraft.

To the address of ATs with directional antennas in the L-band, it is possible to provide a total information rate on the downlink from 150 to 180 Mbps in the transmitter's full power mode, which also provides the radar of the given service area (beam=12°) when choosing the appropriate band and signaling-code structure of the OFDM signal.

Such broadband access capabilities provided by the GISS exceed the capabilities of the existing Inmarsat-4, -5, Thuraya and Iridium SCSs.

A promising area for the provision of these services opens up when creating collective use stations on passenger railway transport,  airliners, fishing and river transport vessels, geological parties, etc. Of particular social importance is the equipment of ambulances in remote areas for remote consultations and emergency medical care, as well as the possibility of rapid deployment of small-sized mobile stations in places of disasters and emergencies.

The widest opportunities open up for providing television reportage, for example, from yacht races, rally-marathons such as Dakar, Silk Way, which require only a operator's video camera with a built-in small-sized terminal and a commentator. No redeployment and deployment of automotive satellite reporting stations is required.

A wide range of applications in military applications is provided, including for broadcasting video images and remote control of unmanned aerial, sea and ground vehicles of various bases.

In this note with a summary of the principles of GISS functioning, there is no need for a detailed analysis of possible options for the technical implementation

of a broadband access network, various types of signal-code structures used, access control modes and maintaining the “handover” mode when changing the used spacecraft and / or narrow beams of service, as well as possible options for the implementation of various terminal equipment.

Each of the specialists can give several options for their proposals, how he himself would implement the provision of any kind of communication services, which we all call on.