The goal for operators of spot-beam High Throughput Satellite (HTS) is clear: to improve the economics of satellite communications by increasing the supply and efficiency of capacity. However, the very nature of spot-beam architectures introduces a challenge to achieving this goal.
Achieving a high utilization rate
Here’s the issue: Launching a satellite is a 20-year bet on where customer demand will be located and how big that demand will be. With a traditional wide-beam satellite, the geographic target could be set fairly large. There was broad flexibility to allocate bandwidth to where it was needed on the ground as demand changed over time. And satellite operators could commonly maintain a capacity utilization rate of 90%.
Capacity allocation is much less flexible with a spot-beam satellite. Operators need to determine beam how much bandwidth and power is required for each and where each beam should be pointed. Once an operator has designed the beam pattern, it cannot easily be adjusted. As a result, operators lose much of the flexibility to sell out capacity in the ways they are used to with wide-beam satellites. And the risk is much greater that an operator could underestimate or overestimate demand on the ground.
Any cost equation is a factor of both supply and demand. While spot-beam satellites will add abundant new capacity to the sky, selling out that capacity is the key to better economics. The cost of HTS capacity will likely not come down until it matches utilization rates of fixed satellites. If capacity is locked up in the wrong beams, an operator would only be able to monetize a lower portion. And that would keep costs high.
Steerable beams and channelizers
The industry has begun to address the situation. We are now seeing steerable beams and channelizers onboard satellites to shift underutilized capacity across beams to where it’s needed. This allows for a partially processed payload. However, the timeframe for adjusting capacity allocation is slow. It can be a month-long process to plan and approve a change to the payload configuration, which significantly limits overall flexibility.
Steerable beams and channelizers represent a step forward in satellite design, but the next phase on innovation must focus on a fully processed, intelligent payload.
Satellite manufacturers are now beginning to push for a design that enables bandwidth to be moved across beams based on real-time, dynamic demand. This creates an intelligent payload. The satellite can process the signal in the sky, handling modulation, demodulation and routing based on dynamic demand.
An intelligent payload enables satellite operators to better utilize and sell capacity. Operators regain the flexibility inherent in a wide-beam architecture, while being able to leverage fully the performance advances of spot beams.
With HTS, operators are placing a new round of long-term capacity bets. Securing a high return on investment is not automatic. It requires a solid business case and the flexibility to adjust capacity based on both real-time demand and long-term changes to that demand. In the end, affordable bandwidth will come only when there are enough customers to pay for it.