The expanding demands for commercial satellite communications (SATCOM) services in support of military command, control and intelligence systems has b... Satellite communication - Certification - Military communication - Communication system control - Control systems - Intelligent systems - Intelligent control - Military satellites - Radio spectrum management - Antenna radiation patterns - installation - military communication - military equipment - certification - commissioning - telecommunication terminals - military standards - telecommunication standards - satellite communication - electromagnetic compatibility - collocated communications equipment - satellite communications terminal certification - military applications - commercial satellite communications services - military command and control systems - intelligence systems - EMC compliance - multiband terminals - DD Form 1494 - terminal performance certification - satellite service provider - administration - power spectral density - antenna radiation patterns - classification standards - terminal commissioning process - site survey - terminal alignment - frequency deconfliction - collocated communications systems
SATELLITE COMMUNICATIONS (SATCONI) TERMLNAL CERTIFICATION FOR MILITARY APPLICATIONS
Mr. Richard S. Wexler The MITRE Corporation
M i . Paul A. Major U. S. Army CECOM Space and Terrestrial Communications Directorate Overview
The recently expanding demands for commercial satellite communications (SATCOM) services in support of military Command, Control and Intelligence systems has been met with a plethora of multiband (typically C, X, and Ku triband) terminals. The rapid growth in military use of commercial SATCOM is due in part to a reasonably mature technology and an extensive commercial space segment offering worldwide coverage. The most significant transition towards the military use of commercial SATCOM to date has been demonstrated by the Army. The military's use of commercial SATCOM requires certification and subsequent commissioning of their terminals. Since the majority of the military's multiband terminals being developed are tactical, added demands are placed on the certification and commissioning process. The certification process includes the administration of the DD Form 1494 and terminal performance certification process administered by the satellite service provider. The administration of the DD Form 1494 is key to insuring that the allocated frequency is properly used (e.g., power spectral density and antenna radiation patterns) by the terminal. Terminal performance certification leads to the validation of a SATCOM terminal's performance capability against a defined standard resulting in the classification of the terminal. The classification standards are service provider specific. The commissioning process can include such things as site survey, terminal alignment, frequency deconfliction to ensure that the terminal being commissioned does not cause interference to other possibly collocated communications systems/ equipment. The paper addresses terminal certification, classification and commissioning. Terminal Certification
Terminal certification results in the following benefits: assurance that the allocated SATCOM portion 0-7803-2489-7195$4.00 0 1995 IEEE
of the frequency spectrum resource is properly used by the terminal; the terminal does not cause excessive adjacent satellite interference; and the terminal is Radio Frequency (RF) compatible with other SATCOM terminals or terrestrial communications-based systems. The certification process consists of a two-step process. The initial step involves a lengthy process that leads to approval of the DD Form 1494, which is the equivalent of terminal licensing. Terminal performance certification is generally administered by the satellite service provider (e.g., COMSAT Corp. for the International Telecommunications Satellite Organization [INTELSAT]) to validate the performance capability of the SATCOM terminal resulting in the classification of the terminal against a defined standard. Terminal performance certification (or type certification) relates to a separate process used by the service providers to categorize the performance of a SATCOM terminal for establishing transponder lease costs. When large terminal quantities are procured, often the first 3 to 5 terminals will be subjected to full certification testing and the balance of the production run terminals will be type classified. The requirements and prerequisites for type certification is satellite service provider specific. Terminal certification is required to (1) ensure that the satellite resources are properly utilized, (2) ensure terminal uniformity, (3) provide interoperability and compatibility, (4) guarantee minimum performance, ( 5 ) minimize the potential for generating or receiving unacceptable interference to and from adjacent satellites and other users of a shared transponder, and (6) facilitate intersystem coordination in case unacceptable interference occurs. Terminal certification is accomplished through terminal performance verification testing that includes such things as: antenna testing (e.g., transmit antenna cross-polarization isolation, transmit antenna sidelobe patterns); E1R.P stability; transmit carrier frequency stability, intermodulation test; and measurement of spurious signal frequency and level. The second step, which is referred to as terminal commissioning (and is synonymous with the authority to operate) is briefly 704
providers (typically, the host country's Post, Telegraph, and Telephone (PTT) organization), which may assist in the terminal commissioning process. DITCO is the DOD agent for leasing commercial SATCOM service. The military departments (MILDEPs) have the right to lease commercial SATCOM circuitshervices directly from the service provider, in lieu of using DITCO, as the acquisition agent. At the time of writing this paper, DITCO typically procures commercial satellite bandwidth on a per channel basis; with the pending award of the Commercial Satellite Communications Initiatives (CSCI) Phase I1 effort, DITCO will bundle bandwidth requirements and purchase large bandwidth blocks (e.g., full transponders) to obtain the associated economy of scale. DITCO's Headquarters is located at Scott Air Force Base, Illinois and has three field offices in Fort Shafter, Hawaii (DITCO-Pacific); Elmendorf Air Force Base, Alaska (DITCO-Alaska); and Sembach Air Base, Germany (DITCO-Europe).
discussed in general terms since universal commissioning procedures, which will be deployment scenario dependent, do not exist. The commissioning process typically involves the near-term active coordination that must take place to ensure that the terminal does not generate disruptive Radio Frequency Interference (RFI). Terminal commissioning is based on the results of a site interference analysis. Authorizing a certified terminal to transmit comes about with the successful completion of the commissioning process.
Background The Communications Act of 1934, with amendments, establishes the management of the frequency spectrum resource for all US-based communications. This act partitioned responsibility between federal and non-federal communications users. Responsibility for spectrum management within the Federal sector (including the military) is under the office of the president (recognized to have the constitutional powers to use frequencies that are determined to be in the national interest). Regulation of non-government interstate and foreign telecommunications is vested by Congress with the Federal Communications Commission (FCC). The administration of the use of the radio frequency spectrum for telecommunications is delegated by the president to the Department of Commerce (DOC). Within the DOC is the National Telecommunications and Information Administration (NTIA). Within NTIA, the Interdepartment Radio Advisory Committee (IRAC) is responsible for implementing spectrum management policy. The IRAC is the principle committee that links the federal to nonfederal programs (i.e., coordination between NTIA and the FCC).
DD Form 1494 The DD Form 1494 is used in support of general coordination within the NTIA, application for foreign spectrum support and application for equipment frequency allocation. A separate portion of the form is used to coordinate frequency allocation with the DOD, the NTIA, and the foreign nations. Figure 1 functionally describes the multi-step process flow leading to frequency allocation approval. The terminal approval process is based on the parallel coordination and subsequent successful completion of all three objectives. The process starts with the preparation of a draft DD Form 1494. The DD Form 1494 will typically evolve during the process from an initial draft version to a complete form that includes applicable test data. This form captures the key SATCOM terminal parameters that will branch out for use by the NTIA, the Commander-In-Chief (CINC), and the U.S. Military Communications-Electronics Board (MCEB). The DD Form 1494, which is used to coordinate the frequency allocation application both nationally and internationally, exists as a multi-page form (the minimum page count is typically six pages). The administration process associated with the DD Form 1494 is known as the Joint Frequency Allocation for Equipment Process or the J-12 Process. These three branches in the flow process shown in Figure 1 for frequency allocation often occur concurrently. The minimum time for frequency allocation is four months; however, more typically, the process requires 8 to 12 months (this does not include the Host Nation
Another organization with significant responsibility for the military use of both commercial and defense-based satellite communications is the Defense Information Systems Agency (DISA). Within the DISA organization is the Defense Information Technology, Contracting Office (DITCO). DITCO is chartered with a centralized acquisitiodleasing function to meet the satellite and other various telecommunications requirements of Army, other DOD services, and other government users. Although DITCO does not play a direct role in the terminal certification process, a discussion of the role of their role is in order. DITCO maintains an active relationship with most foreign SATCOM service
exceeding 5 meters, are routinely licensed by the FCC (FCC Declaratory Order, adopted April 1, 1987). Earth terminals that do not conform to the FCCimposed standards must restrict the Effective Isotropic Radiated Power (EIRP), so that their off-axis EIRP is no greater than that of a fully-compliant terminal. For example, the FCC routinely licenses C-band terminals larger than 4.5 meters which fail compliance with Part 25.209 when the "feed" power density does not exceed -2.7 dBWI4 kHz for digital single channel per carrier (SCPC) signals with data rates up to 4.839 Megabits per second (Mbps). The antenna sizes refer to a circular parabolic main reflector for non-circular antennas; the FCC Declaratory Order allows the diameter of the noncircular antenna to be taken as the diameter of a circular antenna which provides a surface area equivalent to the effective area of the non-circular antenna. In other words, the FCC typically approves the terminal on a conditional basis subject to limiting the terminal's off-axis EIRP to a power spectral density that is less than or equal to the spectral density that would typically be allowed for a fully compliant terminal. For example, a terminal with antenna sidelobes which exceed the Part 25.209 requirements by 5 dB may be given conditional authorization to operate as long as the feed power spectral density does not exceed -7.7 dBW/4 kHz. Outside the US, the sidelobe requirements become more relaxed since the sidelobe requirements are based on 3-degree satellite arc spacing. This translates to a relaxation of 3 dB of the antenna's transmit sidelobe envelope rolloff. For example, to limit adjacent satellite interference within the US, the antenna must exhibit a sidelobe roll-off of 29-25 log 10 8 dBi, in the case of international-based locations, the antenna's sidelobe rolloff is relaxed to 32-25 log 10 8 dBi, for angles of 8 between 1 and 7 degrees where 8 is the angle formed between the antenna's main beam axis and the direction considered. Also, to limit interference to US-based terrestrial communications systems, the antenna roll-off is taken as 32-25 log 10 8 dBi (which reflects a 3 dB relaxation). Satellite terminals that do not meet the 29-25 log 10 8 dBi rolloff and were put into service prior to the FCC's 1987 or 1990 revisions of antenna sidelobe performance requirements may be "grandfathered", if these terminals do not cause unacceptable levels of interference.
Agreement (HNA) approval time). Terminal's antenna size, planned deployment location(s), and traffic requirements (e.g., data rate and modulation scheme) will influence the processing duration. DOD directive 4650.1 requires frequency guidance be obtained prior to contractual obligation in regard to either the development or procurement of telecommunications equipment, which is designed purposely to radiate or receive electromagnetic energy. At a minimum, the MILDEP should obtain RF spectrum guidance for communications electronics systems early in the program's development cycle. This early start is of particular importance when the equipment will be deployed in foreign locations where the MCEB is required to coordinate with the hosting nation. Generally, host nation coordination must be administered by the MCEB, prior to executing the fullscale development contract to ensure that all of the agreements will be in place, in time for initial deployment. The US has HNAs for active frequency coordination with select industrialized world nations. Generally, agreements in the form of primary treaties and other international agreements exist among the English speaking nations. The HNAs are typically established through the CINC which may be permanently located in the foreign nation or through the MCEB. The administration of a HNA can be a very lengthy process ranging from 3 months up to 2 years. The HNA can be accomplished in tandem with the foreign spectrum support process. Antenna Performance
A key concern in both terminal certification and operation is the antenna's transmit sidelobe envelope. Due to the ever decreasing orbital spacing of satellites, particularly those parked in the longitudinal region above the equator that covers North America, strict antenna sidelobe and off-axis emission standards have been imposed for C- and Ku-band operation to limit interference to adjacent satellites. Orbital spacing of satellites which serve the US, have been reduced to 2 degrees in 1987 (for Ku-band operation) and in 1990 (for C-band operation). The Code of Federal Regulations, Title 47, Part 25.209 defines the antenna performance standards for both C- and Ku-band, based on the 2-degree arc spacing. Military terminals placed into U.S. domestic service are subject to the FCC requirements. Terminals operating at C-band with antenna diameters larger than 9 meters and terminals operating at Ku-band, having antenna diameters
Terminal certification is accomplished when both the terminal successfully passes the test validation requirements established by the service provider (e.g.,
SATCOM terminal (including all transmit and receive equipment from the modem to the antenna), 2) standard line(s) of off-the-shelf antennas only, or 3) standard line(s) of complete antenna systems (including the Low Noise Amplifier [LNA]). Type approval is subject to manufacturing restrictions, which guarantee manufactured tolerances and control over design changes. For purposes of repeatability, antenna models, for which type approval is sought, need to incorporate reasonable margins in all critical parameters to allow for normal variances expected during manufacturing. The benefits of type certification include a reduction in the efforts, the time, and expense in bringing terminals on-line. Organizations such as INTELSAT, through COMSAT, periodically releases updates to expand their running list of antennas that have been granted type approval.
INTELSAT, PANAMSAT, EUTELSAT) and the DD Form 1494 is approved. During the certification pending phase, a terminal is often granted temporary authorization to operate within a prescribed set of restrictions. Approval to access the Space Segment can be granted to an earth station applicant in a few days to a few months, depending upon the equipment used, completeness of test data submitted, the availability of the service provider's test facility and the supporting personnel, and the outcome of the verification tests. For a SATCOM terminal, which uses equipment that has received prior approval in terminals previously approved by the service provider, the review and evaluation cycle can be shorter and move on to the verification test phase and take only a few hours to complete.
The commissioning process varies widely based on both service provider and host nation requirements. Universal commissioning procedures do not exist. It is important to note that terminal certification is a necessary but not sufficient prerequisite to authorize a terminal to transmit. The commissioning process can include such things as site survey, local frequency management coordination, terminal alignment (for example following the INTELSAT Satellite System Operations Guide [SSOG] procedures), frequency deconfliction (or EMC compliance verification) to ensure that the terminal under test does not cause interference to other possibly collocated communications systems/ equipment, a co-site interference analysis needs to be performed. Compucon, Comsearch and others provides a for profit service and investigates the likelihood of co-site interference to other communications systems, as well as potential susceptibilities to the SATCOM terminal. Compucon and Comsearch maintain an extremely large database with emphasis on C-band communications systems, since C-band is shared between terrestrial and SATCOM-based users. These databases are recognized as valid by the FCC. However, the use of SATCOM terminals by the military (i.e., Federal Government entity) is outside the jurisdiction of the FCC. The commissioning process can also be assisted by the Joint Spectrum Center (JSC - formerly designated the Electromagnetic Compatibility Analysis Center [ECAC]) located in Annapolis, MD.
The typical earth station's access md approval procedure consists of the ollowing steps: Application for approval to access the space segment, A review and evaluation of the application, Earth station verification testing, Earth station service initiation procedures, and Service cut-over.
The terminal contractor will typically submit the applications and the antenna range data to the service provider (or signatory in the case of INTELSAT). The service provider will review the application and the antenna range test data and may grant antenna (or terminal) approval on a "type basis," rather than on a single, unique antenna (or terminal) model basis if adequate performance statistics for the antenna's (or terminal's) production run are available and consistency is adequately demonstrated in the manufacturing process. It is worth noting that certification by the satellite service provider can be applied to just the antenna assembly. Satellite service provider certification is applicable to the following antennahermina1 configurations; 1) the complete
Certain countries may have additional rules and regulations governing the import of communications equipment, including transportable SATCOM terminals. Such local rules and regulations may vary from country to country and are outside the jurisdiction of the service provider. As a minimum, a transportable terminal may have to obtain a new certification from the second country's Postal Telephone and Telegraph (PTT) organization before that transportable terminal is allowed to operate. The HNA procedure should be sufficient to allow transportable terminals to move from one country to another, provided the HNA has been prearranged with the country the terminal is moving into. However, the use of these terminals in a foreign nation may invoke an up front fee to the host nation (this fee is independent from the satellite service provider's fee for service) commonly referred to as "landing rights."
t Concepts of
Performance Characteristics Derived f r o m On-Going C o n t r a c t
DD Form 1494
AMC - MACOM -
HQDA DISC4 Review
DoD V e r s i o n J-12 Working Group CINC MCEB
Corrective Action Missing Information Coordinate w i t h Host
P r e p a r a t i o n Guide
DD o r m 1 4 9 4 V e r s i o n s
Foreign V e r s i o n
IRAC S p e c t r a l Planning S u b c o m m i t t e (SPS) International Notification GrOUD (ING)