CHAIRMAN OF THE JOINT CHIEFS OF STAFF INSTRUCTION

CHAIRMAN OF THE JOINT CHIEFS OF STAFF INSTRUCTION J-6 CJCSI 6232.01 DISTRIBUTION: A,B,C,J,S DECONFLICTING JTIDS/LINK 16 OPERATIONS 1. Purpose. This instruction implements policy, ensuring the operational use of the Joint Tactical Information Distribution System/Multifunctional Information Distribution System (JTIDS/MIDS) does not exceed pulse density (time slot duty factor (TSDF)) limitations specified in National Telecommunications and Information Administration (NTIA) restrictions and subsequent Military Communications Electronics Board guidance. This instruction will be utilized by all JTIDS/MIDSequipped units operating in the vicinity of the United States, its territories, and possessions, or operating in a US-designed and managed JTIDS/MIDS network, regardless of geographic location subject to host nation restrictions as required. 2. Cancellation. None. 3. Applicability and Scope. This instruction applies to the Military Services, Joint Staff, combatant commands, and those activities and agencies reporting to the Chairman of the Joint Chiefs of Staff. This instruction also applies to any military units from other nations and/or coalition forces operating within 200 miles of the United States, its territories, and possessions, or as part of a US-designed and managed JTIDS/MIDS network. This instruction provides the policy, definition, procedures, and organizational responsibilities to manage JTIDS/MIDS pulse densities. These deconfliction procedures apply to all DOD JTIDS/Link 16 equipped systems (herein referred to as "JTIDS") or non-us MIDS/Link 16 equipped systems (herein referred to as MIDS ) using Tactical Digital Information Link J (TADIL J) and the Interim JTIDS Message Specification (IJMS). 4. Policy. The military forces of the United States, and other military forces operating in US-designed and managed networks, must ensure units operating JTIDS/MIDS do not interfere with navigational aids (NAVAIDS) operating in the same frequency band (e.g., Identification Friend or Foe [IFF] and TACAN). To 1

support this, JTIDS has been granted frequency assignments for specific operational areas. JTIDS/MIDS operations must be deconflicted where these geographical areas overlap and when operations are to occur: (1) that separately comply with their individual frequency assignment authorization, and (2) whose composite time slot duty factor (TSDF) may exceed the pulse density limitation as set forth by the NTIA. The individual units, where possible, must deconflict these operations and ensure there is no violation of NTIA restrictions. If the local units cannot deconflict themselves, a higher authority within the JTIDS/MIDS/multi-TADIL network design and management process (e.g., JTIDS Deconfliction Authority) must determine what methodology to use to ensure compliance with NTIA restrictions. The ultimate authority for deconfliction of JTIDS/MIDS operations is the Joint Staff. 5. Definitions. See Enclosure D. 6. Individual and Organizational Responsibilities. See Enclosure A. 7. Procedures. See Enclosure B. 8. Effective Date. This instruction is effective upon receipt. For the Chairman of the Joint Chiefs of Staff: \Signature\ CHARLES T. ROBERTSON, JR. Major General, USAF Vice Director, Joint Staff Enclosures: A--Individual and Organizational Responsibilities B--Procedures C--NTIA Restriction Letters D--Glossary 2

DISTRIBUTION Distribution A, B, C, and J plus the following: Copies Secretary of Defense... 10 President, National Defense University... 25 President, Armed Forces Staff College... 25 President, Industrial College of the Armed Forces... 25 Joint Interoperability and Engineering Organization... 10 i

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ENCLOSURE A INDIVIDUAL AND ORGANIZATIONAL RESPONSIBILITIES 1. The Joint Staff. The Director of C4 Systems, Joint Staff, is assigned primary responsibility for ensuring compliance with NTIA restrictions. The Joint Staff is also responsible for: (a) Specifying the final JTIDS Deconfliction Authority for setting policy and for deconflicting joint or combined day-to-day JTIDS/MIDS operations when conflicts occurring at lower levels cannot be rectified. (b) Monitoring the execution of policy to ensure all NTIA restrictions are met by JTIDS/MIDS-equipped units. (c) Acting as liaison with the FAA for the establishment and execution of policy regarding deconflicting JTIDS/MIDS operations, exercises, training, and tests. 2. Military Services and Defense Agencies, will: (a) Ensure JTIDS/MIDS-equipped units are aware of the NTIA restrictions. (b) Ensure JTIDS/MIDS equipped units have the resources to comply with established policies for deconflicting operations at the lowest level possible. (c) Act as the final authority for deconflicting individual service or defense agency JTIDS/MIDS operations within that service or defense agency. (d) Provide resources to support the Joint Network Design Library and JTIDS Deconfliction Authority in the execution of this policy. 3. JTIDS/MIDS Deconfliction Authority. The JTIDS/MIDS Deconfliction Authority is the senior joint operational commander, at the lowest level of command, common to both units. Should there be no common commander, e.g., conflicts arising between an operational unit and a test unit, the Joint Staff will act as the deconfliction authority and base a decision on technical advice and recommendations from the Joint Network Design Library authority. 4. The Joint Network Design Library. Acts as the single point of contact/ repository for all JTIDS/MIDS/Link 16 networks. Additionally, the facility will: A-1 Enclosure A

(a) Provide a 24-hour point of contact to address all JTIDS/MIDS/Link 16 network requirements who will provide an immediate response to all contingency network requests. (b) Receive, store, and catalog JTIDS/MIDS/Link 16 networks on behalf of the Joint Staff as they are developed. (c) Provide technical and operational support to CINC, Service, agency, and Joint Staff for pulse density deconfliction. 5. Assignment Controllers. Assignment controllers are unit office of primary responsibility for operations within a frequency authorization area. Assign-ment controllers are responsible for: (a) Ensuring all operations within the frequency assignment authorizations have been coordinated and satisfy NTIA restrictions. (b) Working with other units and assignment owners to satisfy operational requirements for JTIDS/MIDS use in their geographical area. 6. Communications Planners. Planners of existing and future operations, exercises, training, and tests will: (a) Coordinate use of existing JTIDS frequency assignment authorizations with the access controllers responsible for the authorized areas of use as part of the same process as coordinating airspace. The number of those access controllers affected increases with scope of operations. (b) If a JTIDS/MIDS frequency assignment does not exist or cannot support the mission for the desired area of operation, submit a temporary frequency request in accordance with existing frequency management directives. (c) Ensure all of the forces arriving to participate in JTIDS/MIDS operations are included in the coordination process. (d) Work with the access controllers to satisfy NTIA frequency assignment authorization restrictions using the above methods. A-2 Enclosure A

(e) Deconflict foreign military JTIDS/MIDS-equipped platforms under the operational control of US commanders for contingency operations, testing, exercises and unit training within the US and its territories and posses-sions, or within US-designed and managed JTIDS/MIDS networks, regard-less of geographic location subject to host nation restrictions as required. The logical organizational relationship is shown below in Figure 1. FIGURE 1 - Deconfliction Organization Relationships A-3 Enclosure A

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ENCLOSURE B PROCEDURES 1. General Approach. Deconfliction of JTIDS/MIDS operations can best be achieved by keeping the majority of the day-to-day coordination at the lowest level possible. This concept supports both near- and long-term solutions to the deconfliction problem as more assignments are approved and geographical overlap increases. In most cases, JTIDS/MIDS operational deconfliction can be treated the same as clearances for military operating areas (MOAs). Every MOA has a unit that is responsible for its control. Other units wishing to use that MOA must coordinate its use through the controlling unit. A similar approach to deconflicting JTIDS/MIDS operations involves assigning a controlling unit to each JTIDS/MIDS authorized operational area. If a unit wishes to operate JTIDS/MIDS anywhere within an area under the control of another JTIDS/ MIDS unit, it must be coordinated with the controlling unit. This coordination will take place well in advance of operations, via record traffic in the near-term and via an on-line data base in the long-term. For the remainder of this instruction, coordination will encompass the use of either voice or an on-line data base depending on the available capability. Options available to units with a requirement to deconflict operations include but are not limited to: a. Providing times to different units requiring the use of a single geographic area. b. Limiting the use of network capacity to all units so that the total pulse density in any given area complies with NTIA restrictions. c. Changing the geographical disposition of forces to reduce the pulse density in an area where JTIDS/MIDS use is particularly heavy. 2. Deconfliction Procedures. Communications planning offices of primary responsibility (OPRs) for operations, exercises, training, and tests and demonstrations are also the OPRs for ensuring NTIA restrictions are followed. Using the available options for deconflicting operations, communications planners will coordinate with controlling units for each frequency authorization area affected by the operation, exercise, training, or test and demonstration. This coordination will be done as part of the normal planning process of the exercise and should be accomplished at least as far in advance as coordination of airspace use. Planners will be provided with the constraints placed on JTIDS/MIDS use, and will incorporate those limitations into the JTIDS/MIDS B-1 Enclosure B

portions of the multi-tadil network. Any conflict between the planners and the controlling units not resolved at a local level will be elevated to the next higher echelon. For routine operations or training, a general policy should be established for an assignment to reduce the requirement for constantly coordinating the use of JTIDS/MIDS within that frequency authorization area. Only unique circumstances (e.g., operations beyond what that frequency authorization supports) should generate the need for additional coordination. B-2 Enclosure B

ENCLOSURE C NATIONAL TELECOMMUNICATIONS AND INFORMATION ADMINISTRATION (NTIA) RESTRICTION CORRESPONDENCE Doc. 28S43/1-1.14.10/6. 2 For Information Ref. 21167/1-1.14.10 UNITED STATES DEPARTMENT OF COMMERCE National Telecommunications and Information Administrations and Washington, D.C. 20230 USAF Frequency Management Agency (AFFMA) 4040 North Fairfax Drive, Suite #4 Arlington, VA 22203 Dear Colonel June 7, 1994 An interim certification of spectrum support for-360 low rate initial production (LRIP) JTIDS Class 2 terminals was approved by the NTIA in a letter to your office dated August 29, 1989. Since that time, a series of positive steps has occurred, including modification and/or reevaluation of some aspects of the terminal Electromagnetic Compatibility (EMC) Features, and demonstrations of those features for the Class 2, Class 2H with 1030/1090 MHz notch filtering, and Class 2M terminals. Furthermore, the principals of the Spectrum Planning Subcommittee Working Croup 1 (SPS WG-1) have reviewed and accepted the EMC Feature implementations. Based on this SPS WG-1 acceptance, spectrum support certification is approved for the Class 2/2H/2M terminals for operations at a 40/20 time slot duty factor (TSDF) as stipulated in IRAC Document 21167. It should be understood that only those JTIDS capabilities permitted by lrac Document 21167 are allowed for uncoordinated operations; that is: - 40/20 TSDF - 258 pulses per time slot (or RTT messages) - Dedicated access only - All access modes which could result in multiple transmissions in a time slot shall be prohibited (this includes the Enhanced/Repromulgation relay functions) - Single net (net 0 only) - No transmissions in adjacent time slots - Nominal 200 watts terminal output power In addition, the following specific limits are imposed for Class 1 and Class 2/2H/2M terminal collocated operations and operations in the vicinity of ground-based ATC equipment. Note that some modifications have been made to the limits specified in my August 29, 1989 letter. These changes reflect the separation distances specified in the expanded JTIDS certification (IRAC Document 27439) for JTIDS operations at 100/50 TSDF. C-1 Enclosure C

a. Blanking of the low-level-detector (LLD) EMC feature is permitted, if required, to ensure that JTIDS transmissions are not inhibited due to interference from collocated ATC transmitters. The duty cycle of this blanking function is limited to 6 percent. The blanking signal sources are limited to only ATC transmitters operating in the 1030/1090 MHz bands, that is, IFF, ATCRBS, Mode S and TCAS functions. b. Interference with the performance of onboard ATCRBS, Mode S or TCAS avionics is prohibited. Integration procedures used to achieve JTIDS compatibility with onboard ATC equipment shall not affect their operation. Specifically, the blanking of ATC equipment operating in the 1030/1090 MHz bands to provide compatibility with collocated JTIDS terminals is prohibited. c Ground-based JTIDS terminals shall be located such that TACAN and DME/N beacons will be protected from JTIDS signals that exceed a peak power level of -33 dbm at the beacon receiver input. d. Ground-based JTIDS terminals shall be located such that ATCRBS interrogators will be protected from JTIDS signals that exceed a peak power level of -20 dbm at the interrogator receiver input. e. Both ground-based and airborne JTIDS terminals shall, at this time, be prohibited from operating within radio line-of- sight (RLOS) or operational DME/P beacons or operational Mode S sensors. This RLOS restriction will be reviewed upon completion and documentation of the JTIDS EMC Test and Evaluation program and JTIDS report review process. If the FAA, through the normal frequency assignment process, requests operational status for either of these equipment, the implication of the RLOS restriction will be reviewed by the SPS WG-1 Coordination Procedures Subworking Group. f. Class 2H terminals shall be operated only in concert with an accepted 1030/1090 MHz notch filter assembly (NFA). An accepted NFA shall be defined as one whose-signal rejection characteristics have been provided to, and approved by, the SPS WG-1. C-2 Enclosure C

This approval of JTIDS Class 1 and Class 2/2H/2M terminals for 40/20 TSDF operations supersedes the approval of August 29, 1989. In addition, the constraints listed herein are subject to relaxation if future operational experience or test data, analysis and documentation indicate such relaxation is warranted. Sincerely, \Signature\ William Gamble Deputy Associate Administrator Office of Spectrum Management cc: R Hove, OSD/C 3 I G Markey, FAA/ASR-1 N Pollack, AFFHA R Seach, Convener, SPS WG-1 C-3 Enclosure C

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ENCLOSURE D GLOSSARY Specific definitions for this instruction are: 1. Joint Tactical Information Distribution System/Multifunctional Information Distribution System (JTIDS/MIDS). JTIDS and MIDS are high capacity, secure, jam resistant digital information transfer systems operating in the UHF band on 51 discrete frequencies between 960 MHz and 1215 MHz. MIDS is a technology insertion program to reduce component size and weight while maintaining all JTIDS functionality. The United States, France, Italy, Germany, and Spain are currently participating in the MIDS program. 2. JTIDS Network Design and Management Process. The process by which connectivity plans for JTIDS operations are designed and platform loads for an individual connectivity plan are developed and disseminated to all of the platforms participating in that plan. 3. Time Slot Duty Factor (TSDF). The percentage of time slots in which transmission occurs relative to time slots available in a 12 second JTIDS/MIDS frame. 4. Effective Time Slot Duty Factor. A calculation of time slot duty factor that incorporates normalizing Packed 2 Double Pulse and Packed Four Time Slots (444 pulses) to their Standard Double Pulse and Packed Two Single Pulse Packing (258 pulses) time slot equivalent. 5. Pulse Density. The total JTIDS effective TSDF resulting from the transmissions of all the JTIDS/MIDS terminals within a 200 mile radius circle. 6. JTIDS/MIDS Frequencies. Figure 2 shows the 960-1215 MHz frequency band and its use by civil and military aviation navigational systems. Chart A indicates the frequencies used by the Air Traffic Control Radio Beacon System (ATCRBS), Mode S systems, and Identification Friend or Foe (IFF) systems. These systems use 1030 MHz for interrogations and 1090 MHz for replies. Civil aviation Distance Measuring Equipment (DME) operates on frequencies from 962 MHz to 1213 MHz in 1 MHz increments. Each DME channel uses two frequencies, one for interrogations from aircraft for distance information, and one for DME beacon replies. Military Tactical Air D-1 Enclosure D

FIGURE 2 - JTIDS/MIDS Operating Frequencies D-2 Enclosure D

Navigation (TACAN) systems also use frequencies from 962 MHz to 1213 MHz in 1 MHz increments. Each TACAN channel uses two frequencies, one for interrogations from aircraft for TACAN distance (similar to DME), and one for replies to TACAN distance interrogations and TACAN azimuth information. Chart B shows the range of frequencies used by DME and TACAN systems. JTIDS Mode 1 operates on 51 frequencies within three subbands: 969-1008 MHz, 1053-1065 MHz, and 1113-1206 MHz. These subbands are shown in Chart C. Within these subbands, the JTIDS frequencies occur at 3 MHz interval. These 51 frequencies are shared with DME/TACAN equipment. JTIDS terminals are designed to exclude JTIDS transmissions between 1008 MHz and 1053 MHz and between 1065 MHz and 1113 MHz to prevent interference with ATCRBS/Mode S/IFF systems. In aircraft installations, the JTIDS terminal also provides the TACAN function. Therefore, airborne JTIDS terminals are capable of using the entire 962-1213 MHz range for TACAN functions, but restrict JTIDS transmissions to the three subbands described above. 7. Frequency Allocation. An authorization, from the recognized authority, by type of radio service for a system of equipment to be designed to use a particular band of radio frequencies under specified conditions. 8. Frequency Assignment Authorization. An approval from a recognized authority, based on specific situational descriptions, to transmit on specified radio frequencies. 9. Frequency Clearance. An authorization given by the responsible administration for the use of frequencies for a radio system to operate and provide a specified class of service, (i.e., temporary assignments, jamming exercises, etc.). 10. MOA. Military operating area. 11. US Department of Commerce, National Telecommunications and Inform-ation Administration (NTIA). NTIA was established in 1978 by Executive Order 12046. NTIA is the Executive Branch telecommunications policy advisor to the President and manager of Federal Government uses of the spectrum. D-3 Enclosure D

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