Early last week, Intelsat held a press event at the Satellite 2013 conference on the topic of high throughput satellite (HTS) development. HTS has the potential to transform the role of satellite communications in both commercial and government networks. As such, we wanted to share what we see as the core elements that make up HTS and the business decisions around how best to provide it.
So what exactly is HTS? A high throughput satellite is a satellite that has many times the throughput of a traditional FSS satellite using the same amount of allocated frequency on orbit. These satellites accomplish this by taking advantage of frequency reuse and spot beams. By doing so, they reduce the cost per bit delivered, regardless of spectrum choice.
To understand how HTS systems are developed, there are five core components to consider. These five components impact the business model for HTS and the enhanced service offerings it offers to customers. There are no hard and fast “right” answers to these components. They often balance sometimes conflicting goals, depending on variables like geographic region, customer architecture or specific applications.
The first component is Throughput itself. Throughput is made up of bandwidth, measured by megahertz (MHz), and efficiency, measured by bits per second per MHz. Think of it as bandwidth being the overall size of the pipe, and efficiency is how fast the content can travel through each individual connection. Deciding which to maximize for – aggregate bandwidth or greatest individual throughput – can often be conflicting technical goals.
Efficiency is also a component of its own for technical design. Spot beams drive efficiency up, but too many spot beams close together can result in interference which drives efficiency down. Putting greater distance between beams increases efficiency, but reduces frequency reuse, resulting in lower overall satellite throughput. Improved efficiency will enable carrier-grade services and performance, allowing users to expand their addressable markets.
Coverage is the third critical component of HTS. The size of the desired coverage area is a major variable, since the number of beams is constrained by satellite resources like power and mass. And the size of beams depends on the frequency selected. The ability to combine wide and spot beams will be critical in providing government users coverage when and where they need it.
Network Architecture is the fourth HTS component. HTS designs allow for open or closed network architectures. Open architectures are compatible with many common network topologies such as Star, Mesh or Loopback configurations. Applications commonly associated with a closed system include consumer broadband and trunking. Open architectures are optimal for network operators that need to maximize performance of their applications to specific locations.
Spectrum is the final HTS component to consider. HTS can be developed in any frequency band, driven by considerations like beam size, coverage, atmospheric conditions and ground technologies.
Obviously any of these components could be dealt with in far greater technical detail. We feel this is a useful framework with which to understand HTS. It’s an introduction, and one we hope helps users grasp how HTS will dramatically increase the power and utility of satellite communications.