Application Technology Strategy, Inc., (ATSI), is the satellite consulting firm founded by Bruce Elbert, leading satellite expert and consultant, technologist, educator and author of standard industry books. We emphasize the how of developing satellite systems.

Ground Segment

The areas of our attention and expertise extend throughout the satellite system, comprised of the Space Segment and the Ground Segment. These are defined in the following figure.

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The Ground Segment, which is the domain of the earth station operator or network service provider, is potentially more complex because success requires that many factors be addressed correctly (or at least better than your competitor or opponent).

The Ground Segment in the first figure contains many user terminals - illustrated by very small aperture terminals (VSATs) - and a single hub earth station that ties the network together in the form of a star.  Likewise, this architecture may be used to deliver digital content such as television programs, audio services, web pages, and innovative forms of multi-media. Content Distribution Networks of this type should be designed as a consistent whole, based on the application requirements and existing and evolving standards for compression and efficient data management. Also to be considered are the satellites available vs. those to be developed to provide space segment service. Our systems approach to this process is described in a recent paper on broadband data communications using VSAT technology. The alternative to the star VSAT netwrork is to use a mesh architecture that allows direct communication between remote earth stations without passing through a hub.  Depending on the design of the space segment and air interface, other types of user terminals that could be employed include:  lap-top and hand-held satellite telephones, broadband data modems for PCs, TV receivers, and video teleconferencing terminals. Equipment for the ground segment is supplied by a variety of manufacturers and integrators, including specialists in satellite communications and, in some cases, more familiar communications and consumer electronics firms in the global marketplace. Selecting among these sources is perhaps the largest single challenge.

Important factors for the Ground Segment include:

  • Understanding the market and what customers want to achieve in their business
  • Offering a package of services that solves communications problems or deliver content to a hungry marketplace.
  • Having a solid technical platform that extends services to users on a straightforward and economical and reliable basis.
  • Delivering user equipment and service through effective channels of distribution and fulfillment.
  • Implementing appropriate operation and administrative systems, including customer care, accounting and billing.
  • Timely entry in domestic and international markets, taking account of regulatory, business and cultural barriers.

We are able to help define the ground segment architecture, technical specifications, organization structure, and management systems to address the application requirements. This is an every-changing landscape of technology (hardware and software) and management methodology. Currently, the most popular satellite network technology is the VSAT, now available in fixed and mobile installations.

Fundamental to the proper specification of satellite communications is the performance of the radio frequency (RF) link between earth and space. The link budget process, reviewed under our Education and Training tab, provides the most basic understanding of the earth station-to-satellite path. In addition, the distortion characteristics of non-linear amplifiers (TWTA, SSPA and klystron) impact different waveforms in different ways. Further complicating the study is the interaction of these properties on the ground and in space. The link budgeting process may have to be supplemented by computer simulation and hardware measurement in the laboratory or with a real satellite. The following article from RF Design magazine, co-authored with Dr. Maurice Schiff, provides realistic guidelines for this type of expanded effort.

Download RF Design Article, "Simulating the Performance of Communication Links with Satellite Transponders," by Bruce Elbert and Maurice Schiff.

Whether using video networks, VSATs or major gateways, the key to success is always to set the requirements early on, update those requirements as more is learned, and employ the right implementation methodology along a path of quick adaptation to evolving requirements, users and markets.

Examples of our services to space and ground segment clients