Ku-band Geostationary Satellite Transponder Bandwidth

STATEMENT OF WORK Title: Ku-band geostationary satellite transponder bandwidth Date: 5 June 2026 I. BACKGROUND INFORMATION NIST is one of the official sources of time and frequency for the United States and for international coordination of time and frequency. The Time Realization and Distribution group maintains the primary frequency standards, the time scale, and the time transfer operations for the U.S. contribution to the International Bureau of Weights and Measures. The primary frequency standard for the U.S. is currently our cesium fountain standard, NIST-F4. The time scale is a weighted average of several atomic clocks whose frequencies and linear frequency drifts are regularly measured against primary frequency standards. Two-way satellite time/frequency transfer (TWSTFT) is the method for comparing our clocks with standards around the world for our participation in the generation of international atomic time (TAI and UTC). II. PURPOSE A network of nineteen national metrological laboratories (NMIs) and technical institutes (the Collaboration), including NIST, uses Ku-band geostationary satellite transponder bandwidth to enable high precision exchange of time signals using the two-way satellite time/frequency transfer (TWSTFT) technique. NIST uses the satellite link as the primary method of transmitting NIST’s realization of Coordinated Universal Time (UTC) to the International Bureau of Weights and Measures (BIPM) via European NMIs. The satellite TWSTFT technique is the only time transfer method capable of the required sub- nanosecond precision over trans-continental distances, free from dependence on Global Navigation Satellite Systems (GNSS) like GPS, and accepted by BIPM. Because the Collaboration’s TWSTFT network is currently operating with an installed base of equipment (here, “Earth stations”), several service parameters are fixed for compatibility. The purpose of this acquisition is continuation of the active network without interruption. PLACE OF PERFORMANCE A satellite transponder physically exists in geostationary orbit around Earth. Transponder service is provided by administrative activities at vendor’s place(s) of business. Once authorized, transponder service is highly automated and available with little to no interruptions over the entire period of performance. PERIOD OF PERFORMANCE From November 27, 2026, 00:00 UTC through November 26, 2027, 23:59 UTC. III. SPECIFIC REQUIREMENTS TASKS Task 1 – Provision of compatible Ku-band geostationary satellite bandwidth The contractor shall: -- 1 of 5 -- 1.1 Acquire and permit NIST and the network of laboratories listed in Table 1 below (the Collaboration) the use of non-preemptable (reserved) transponder bandwidth on a station- kept geostationary satellite. Additional requirements follow. 1.2 Ensure uplink carrier(s) are within the range 14.0 GHz to 14.5 GHz. 1.3 Ensure downlink carrier(s) are within the range 10.95 to 12.5 GHz. 1.4 Ensure the polarization type is linear and cross-polarized. Collaboration Earth stations must not be required to change polarizations or re-point antennas to communicate with any other Collaboration Earth station. Carrier frequencies may change to support “cross-strapped” transponders enabling communication links between North America and Europe. See attached document “2026_05_16_request_for_Ku_bandwidth_ROM” for additional details and examples. 1.5 Provide a transmission plan including a link power budget, availability estimate, and coverage for all Earth stations listed in Table 1 below. Note: the two North American stations need not communicate with each other but must be able to communicate with all European stations. All European stations must be able to communicate with each other and the North American stations. Roughly, based on public information, the required longitude of the satellite will be within 30°W through 45°W. 1.6 Ensure the transponder’s equivalent isotopically radiated power (EIRP) >= 42 dBW unless justified by the vendor’s transmission plan and link budget. 1.7 Ensure the transponder service is compatible with existing, already-deployed Earth station modems: make/model is TimeTech SATRE. The transmission mode is a pseudorandom noise (PRN) code at a 2.5 Mc/s symbol rate. Modulation is binary phase-shift keying (BPSK). The occupied bandwidth is approximately 4 MHz but should be accurately budgeted by the vendor’s transmission plan. Additional Earth station information needed to compute a transmission plan is listed in Table 1, below. 1.8 Ensure the Collaboration is permitted to use the transponder service over the full term of service, one year from November 27, 2026, through November 26, 2027. 1.9 Provide for a billing arrangement that allows for an existing cost-sharing arrangement between Collaboration members: 25% to NIST, 25% to U.S. Naval Observatory (USNO), 50% to Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig, Germany. 1.10 If not included in the transmission plan, vendor shall provide a signed letter of supply from the owner/operator of the proposed geostationary satellite transponder, guaranteeing availability of service over the specified term. IV. GENERAL REQUIREMENTS Include all requirements that are not specific tasks but are applicable to the overall contract and the work that will be performed. For example, IT Security, Government Property, Public Affairs Clearance, OMB clearance, printing, data rights, etc. Government Responsibilities NIST and each Earth station in the Collaboration, agree to perform transmission test and tuning to the satisfaction of the geostationary satellite transponder owner/operator prior to regular link operation. The Collaboration also agrees to abide by transmission control requirements issued by the transponder owner/operator. Government Furnished Property -- 2 of 5 -- All government furnished property required to enable use of the transponder link already exist at Collaboration Earth stations and shall remain t…