Smart Gateways Concepts for High-Capacity Multi-beam Networks

The support of high capacity broadband multi-beam satellite networks requires the implementation of a large number of gateways to cope with the high feeder link throughput generated by the large number of satellite user beams. Although today the state-of-the-art satellite broadband systems exploit Ka-band for the feeder link, to further increase the system capacity Q/V-band exploitation will be required. When exploiting Ka or Q/V-band (the latter in particular) gateway site diversity becomes a must to ensure the required high feeder link availability. Conventional site diversity is too onerous when the number of gateways is large as it is doubling the number of system gateways. The novel Smart Gateway Diversity Concepts (SGC) described in the paper are representing possible ways to exploit the inherent presence of multiple physically separated gateways in high capacity systems to achieve the required feeder link capacity minimizing the number of required gateways. The key idea is to exploit the inherent presence of several spatially separated gateways to cope with the required large feeder link bandwidth to achieve the required fading link availability. This requires gateway interconnection and ad-hoc payload architectures allowing seamless user traffic hand-off from the faded gateway(s) to the unfaded ones. In current systems each gateway serves a distinct cluster of beams thus this approach is not possible. The proposed smart gateway schemes allow to significantly reducing the cost of the ground segment (number of gateway antennas and associated RF front-end). Depending on the SGC scheme, a certain level of the transparent payload complexity increase is required. Some payload reconfigurability will be in any case required to support the need for gateway switchover to a redundant one in case of failure. Furthermore, all the proposed payload architectures are all analogue and exploits technologies readily available. The paper provides a detailed description of the different Smart Gateway Diversity Concepts and associated architecture for the ground and space segment.