Putting that comparison aside, the only ubiquitous, fully global, Ka-band system – namely Inmarsat’s Global Service Beams – has a 19% hole in each “ubiquitous” coverage area. Per the blog’s terminology, each satellite stiches together 89 spot beams to provide ubiquitous coverage. However, per Inmarsat, at any one time, only 72 of those 89 beams can be active. In other words, at any given time, 19% of the beams are off, so 19% of the coverage area has no meaningful bandwidth available for use.Another key coverage difference, and advantage, of Ku- over Ka-band HTS is satellite depth and overlap. There are four Inmarsat I-5 GX satellites to cover the entire globe. Two thirds of all locations see only a single I-5 satellite and are thus covered by only a single Global Service spot beam. There is no overlapping satellite to provide additional and/or backup capacity. The Intelsat Epic constellation has five satellites worldwide which are designed to provide layered coverages in many areas, with a sixth one launching in 4Q18. In addition, these HTS overlays are backed up by Intelsat’s global constellation of wide-beam satellites. This depth of coverages provides end users with resiliency and redundancy unavailable in Ka-band. Switching between these Ku-band options is possible because of the open architecture compatibility between Intelsat EpicNG, Intelsat wide-beam and other Ku-band HTS and wide-beam satellites. This aspect of open architecture is a critical aspect of Intelsat Epic that is completely unaddressed in the Inmarsat blog post. An HTS offering can be either ‘open’ or ‘closed.’ Each type has common characteristics in terms of technologies used and services supported. Closed HTS architectures include ViaSat Exede, Inmarsat Global Xpress, Hughes Network Systems Jupiter, and Eutelsat KA-SAT. Open HTS architectures include Intelsat Epic, Telesat VANTAGE and SES Ku HTS, to name a few. On a closed-architecture HTS, a customer can use only operator-selected platforms and terminals. In addition, there is no switching between closed systems. An Inmarsat GX Ka-band terminal will not operate on ViaSat’s nor Hughes’ Ka-band systems. With Intelsat’s open-architecture Ku-band HTS, users choose their preferred ground equipment, be that an installed base or a newly selected platform. The ability to use existing ground equipment in open systems can lead to substantial cost savings while the ability to select a new platform now, or in the future, protects end users from the trap of proprietary systems where they do not have control. These end user platforms can operate on Intelsat’s and easily switch to others open-architecture Ku-band systems. In addition to requiring proprietary ground equipment, closed HTS systems offer only star topology networks. This means that all remote terminal traffic must route via a limited number of gateways or access stations. It is similar to commercial airline travel, where one must travel through an airline’s hub to reach a certain city even if that is not the shortest or fastest way to the final destination. Closed architecture HTS do not allow loopback within a single spot beam nor custom beam-to-beam connections. Both are possible with Intelsat EpicNG. This flexibility enables faster routing and, possibly more importantly, installation of all ground hardware at end user locations, not at third party facilities. One part of the Inmarsat blog with which I can agree is the call for increased industry and government collaboration in support of command, control, communications, computers, intelligence, surveillance and reconnaissance (C4ISR) operations. Towards that end, Intelsat is constantly innovating, improving the technology on each Intelsat Epic satellite. For example, the soon to be launched Horizons 3e will be the most advanced HTS satellite to enter service. Horizons 3e is the first satellite to feature an entire Ku-band payload utilizing multiport amplifiers that optimize power distribution across the satellite’s beams. With the multiport amplifier, if one spot beam is lightly utilized, its allocated power can be distributed to other beams to meet customer throughput demands. When you distill the facts from the claims and counterclaims, Ku-band SATCOM provides the most compelling HTS value proposition for customers requiring resilient, flexible and secure high-throughput global coverage.
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