SATCOM Networks

SATCOM Networks - Broadband, mobility and innovation for government services. Washington D.C. - To be scheduled. Bruce Elbert, President ASTI, Instructor and Coordinator, and Andrew C. Oak, Chief Engineer, Communications and Network Systems Engineering Group, The Johns Hopkins Applied Physics Laboratory, Invited Expert.

Satellite networks are a core telecommunications resource for military forces and homeland security teams that must locate anywhere and anytime. Because of greater needs for bandwidth and portability, the large fixed earth stations of the past no longer meet demanding requirements of critical units as they deploy throughout the US and worldwide. This course reviews the current framework for using modern communications satellites and looks to the coming years regarding the potential for even more innovation. The approach to the course is at a system level and delves into sufficient technical detail to demonstrate what is feasible and likely to be applied in practice. A fundamental requirement is that broadband services be delivered to end points of demand, and that the service is up and running reliably when and where needed. Accomplishing this, while not trivial, is much easier today than ever before because there are more satellites and more options for ground-based systems that can be architected to meet many of these requirements.

The course reviews critical issues concerning cutting-edge SATCOM technology and services. Principle among these is the selection of the appropriate space segment in terms of the orbit and constellation, satellite architecture, and owner/provider. In achieving broadband access and mobility, the different frequency bands and supporting systems are compared – X, SHF, UHF and Optical wavelengths on the government side, and L, S, C and Ku on the commercial side. Applying satellite technology also requires that the potential user consider the security aspects of interception and harmful interference, both unintentional and intentional.

The enabling and emerging SATCOM technologies that we review assure that points of presence are served regardless of their location whether fixed, temporary or mobile. In the case of the latter, we address portable (including manpack) systems, vehicular mounted terminals, which may offer broadband access on the move, Blue Force asset tracking, and aeronautical platforms that can be either manned or unmanned (i.e., UAVs). These platforms must match the particular application, and the satellites involved with providing domestic coverage for homeland security or internationally for operations in a far-flung theatre.

Currently, SATCOM is the domain of the geostationary earth orbit (GEO) which contains more than 250 operating satellites. With most of these capable of broadband services, it is the primary focus of both users in general and this course in particular. Programs to be reviewed include the Wideband Global SATCOM (WGS), Global Broadcast System (GBS), Mobile User Objective System (MUOS), and the Transformational Satellite Communications System (TSAT). TSAT is particularly interesting as it has as its goal the exploitation of the optical spectrum for use in various defense scenarios.

Also reviewed are purchase of bulk commercial satellite capacity by the US government, notably the GSA Satcom II program and various efforts of the Defense Information Systems Administration (DISA). So that we cover all possibilities, a topic to be addressed is the potential for small, low cost satellites in a variety of orbits which could offer value on the battlefield and home-front of the future.

We discuss three areas that are likely to be very important for broadband SATCOM acceptance throughout commercial and government sectors; the fact that a majority of broadband use is via the TCP/IP Internet protocol family, we see that acceptable latency and throughput over a GEO or non-GEO satellite link is of prime importance. Topics such as TCP/IP acceleration and advanced protocol gateways, routing in space, and possible structural modifications will be covered in the current context. Greater throughput and higher speed are the promise of bandwidth-efficient modulation (BEM) and related waveforms and error-correcting coding schemes. Also, digital on-board processing will provide compact user devices with more flexibility and bandwidth.

To bring these topics together and to life, the course will examine a complete SATCOM requirement and solution involving a mobile broadband application. We will review the need, identify alternatives that can address those needs, and recommend the most suitable and cost-effective approach. The conclusion of the course will embody a review of future trends that will shape SATCOM in the next five to ten years. Central among these is the direction of technology and application at the higher (SHF) frequencies as compared to the opportunities in the optical realm. Also to be addressed is the extent that government users and commercial providers can share risk at a time when demands are great. Underlying the technical foundation is the question of which standards will continue and what new standards are likely to appear and take hold. Future innovations are certainly likely on the ground and so we address hybrid networks that integrate SATCOM with terrestrial wired and wireless systems

Andrew Oak is a member of the Principal Professional Staff at the Johns Hopkins University Applied Physics Laboratory, where he serves as the Chief Engineer for the Communications and Network Systems Engineering Group.  In this role, Mr. Oak has assisted in the architecture definition and development of satellite communications and other wireless systems for DoD and other U.S. Government customers.  He recently supported the U.S. Navy in the development of the Mobile User Objective System (MUOS).  Mr. Oak provided support from early MUOS architecture definition through the recent critical design phase, providing system performance assessments to help the community continually refine and improve the architecture as it progressed through development phases.  Mr. Oak received a B.S.E.E. from the University of Massachusetts at Amherst and an M.S.E.E. from the University of Virginia.