Power to Scale to HTS Networks

Denis SutherlandBy Denis Sutherland, Sr. Manager, Sales System Engineering

In my last blog, I discussed how ground infrastructure providers like iDirect have a tricky job keeping their technology at the pace of change of developments in space.  Much has been said about the exciting changes in the VSAT industry, not least with the many High Throughput Satellites (HTS) launched or planned.

The reality is that there is no common way to build an HTS satellite. O3B is exceptionally different from the other constellations, but we have also seen many other differences in terms of numbers of beams, size of transponders, polarization, onboard process and many other factors. I talked about some of the different business models here.

One thing they have in common is that HTS brings many more beams to cover a similar geographical area. For example, a typical Ku satellite beam could cover Europe, but with an HTS Ka satellite, you may require 30 or more beams.  This multi-beam frequency reuse is obviously one of the key advantages of an HTS architecture, but I will not talk about that here. Intelsat do a very good job on the “teach in video” you can view: http://www.intelsat.com/blog/intelsat-presents-a-high-throughput-satellite-teach-in/

Let’s consider how this change impacts the ground vendors or service providers using a TDMA platform like iDirect.  With a non-HTS Ku satellite, from a design perspective, we would assume for Europe wide coverage that a single DVB-S2 outbound would sufficiently cover the continent,  up to a limited amount of total IP traffic, and we can run some sophisticated modeling to work out numbers of terminals contention ratios, SLA, rain fade with resultant ACM impact. Easy!

On the terminal to earth station side, we have a well-established design methodology here, too, and we grow the numbers of inbound carriers as the IP demand increases, based on similar factors to the outbound. 

What is different with HTS?

Well, for example what if you still want to cover that whole geography (Europe), you now may need 30 outbound carriers and multiple inbound line cards for each beam as well.  A factor of 30 increase – I am sure you can see that carrier density on ground station equipment becomes very important.

How will iDirect help me improve my carrier density?

The good news is that iDirect products have always been very modular and scalable, so accessing multiple satellites from one system has been a differentiator for us during the 10 years I have been at iDirect, using the Series 15000 Universal 5IF hub.

The 5IF universal hub would let you access five spots from one chassis, so five DVB- S2 outbounds.  But our XLC-M line cards could be used in a. M= 8 configuration, 100+ inbound carriers for a single chassis is a realistic possibility.

Wow, that is a lot of carriers! 

The situation continues to improve dramatically with iDX 3.2 and Adaptive TDMA, producing more IP through your inbound capacity. So to make this work, we also improved the chassis itself: we introduced the 15100 to deliver more physical power to each of the  line cards, and support the much increased current draw, basically to facilitate a much better port density.

So is iDirect done there?

No, we are not. We continue to see HTS satellites planned with 90 plus beams, and with multi-satellite constellations that will add up to a lot of carriers. In the future you will see us further increase the carrier density of our hub and line card systems to address these needs.

Will iDirect match developments in Space?

51002Not always but we are working hard to keep up with the diverse deployments across the satellites industry. NSR believes that there will be two main types of HTS networks, one with integrated Ground / Space infrastructure and second with Open space segments.  In both cases and to gain the most value, ground and space architecture will need to be aligned. The one important aspect is to have the carrier density on the ground match the amount of beams you will use in space; in some models that may not be the full spacecraft’s capability! iDirect has solutions to light up a full HTS satellite or just a couple of beams.

iDirect continues to adapt our plans to meet the needs of the evolving Ecosystem that is HTS VSAT.

Please contact me if you want to talk more about how iDirect can power your HTS networks.

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