A3344695_B AS_AJ Modem Specification.docx

A3344695 4 November 2020

4 November 2020 FOR OFFICIAL USE ONLY A3344695

GEN II

ANTI-SCINTILLATION / ANTI-JAM MODEM (AS/AJ)

MODEM SPECIFICATION

Specification No. A3344695 Revision B Date: 4 November 2020

EXPORT CONTROLLED - ITAR

THESE ITEM(S) / TECHNICAL DATA ARE CONTROLLED BY THE DEPARTMENT OF STATE, INTERNATIONAL TRAFFIC IN ARMS REGULATIONS (ITAR), 22 CFR PARTS 120-130, AND CANNOT BE EXPORTED FROM THE UNITED STATES OR SHARED WITH A FOREIGN PERSON WITHOUT PRIOR APPROVAL FROM THE U.S. DEPARTMENT OF STATE .

UNCLASSIFIED//FOR OFFICIAL USE ONLY

REVISION RECORD

UNCLASSIFIED

TABLE OF TBDs

Table of Contents

Table of Figures

Table of Tables

(U) SCOPE

(U) This document establishes the performance, design, fabrication, and test requirements for an Anti-Scintillation/Anti-Jam (AS/AJ) Modem Unit which is a component of the Protected Anti-Scintillation Anti-Jam Wideband Net-Centric System (PAAWNS) to provide the capability to communicate via a perturbed X or Ka-Band satellite link. Possible perturbations include the scintillation effects resulting from an exo-atmospheric nuclear event, intentional or unintentional RF signal interference (jamming), or both.

(U) APPLICABLE DOCUMENTS

(U) The following documents of the exact issue shown, or latest version if undated, form a part of this document to the extent specified herein. In the event of conflict between the referenced documents and the contents of this document, the contents of the higher level document will be considered a superseding requirement. The PAAWNS hierarchy is shown in Figure 2‑1.

Figure 2‑1 (U) PAAWNS Specification Hierarchy

(U) Government Documents

https://iase.disa.mil/stigs/Pages/index.aspx.

(U) Non-Government Documents

(U) CHARACTERISTICS

(U) The modem is designed to communicate via X-band and Ka-Band satellite transponders in a nuclear perturbed environment and in the presence of jamming. The modem uses a unique phase modulated waveform with Turbo coding and interleaving to combat the effects of nuclear scintillation. It also implements spread spectrum operation using frequency hopping to combat the effects of jamming. The nuclear perturbed environment, including the nuclear effect parameters that affect the communications error rates, is defined in Appendix B of the Specification for Protected Anti-Scintillation Anti-Jam Wideband Net-Centric System (PAAWNS), Generation II (A3344693). Detailed descriptions of the various types of jammers anticipated also are included in Appendix A of the same document.

(U) General

(U) Modem Communication Capabilities

(U) The modem shall be capable of communicating between its baseband interfaces to the KGV-90 to one or more distant end modems via host satellite communications (SATCOM) terminals and satellite links. [1MOD-17]

(U) The modem shall be capable of connecting each link processor to one or more transmit and/or receive carrier processors to provide the required link connectivity and throughput rate. [1MOD-20]

(U) The modem shall provide a single wideband IF interface to transport all modulated transmit carriers to the host terminal’s transmission electronics. [1MOD-21]

(U) The modem shall provide a single wideband IF interface to transport all modulated receive carriers from the host terminal’s receive electronics to the modem. [1MOD-1009]

USER DATA

PACKETS

(ETHERNET)

IF

OUT

NETWORK MGT

PACKETS

(ETHERNET)

TRANSMIT

CARRIER PROC

RECEIVE

CARRIER PROC

TRANSMIT IF

PROCESSING

IF

IN

RECEIVE IF

PROCESSING

TRANSMIT

LINK PROC

RECEIVE

LINK PROC

Figure 3.1.1‑1 (U) Communication Capabilities

(U) Link Processing

(U) Transmit Link Processing Functions

(U) The modem shall distribute data carried by multicarrier links evenly across the carriers. [1MOD-44]

(U) The modem shall support at least 49.152 Mb/s (benign environment) nominal aggregate transmit data rate for all links combined. [1MOD-45]

(U) Assignment of link processing input and output interfaces shall be in accordance with the modem configuration control inputs. [1MOD-46]

(U) Receive Link Processing Functions

(U) The modem shall support up to 49.152 Mb/s (benign environment) nominal aggregate receive data rate for all links combined, including the Network Timing Reference (NTR). [1MOD-51]

(U) Assignment of link processing interfaces shall be in accordance with the modem configuration control inputs. [1MOD-52]

(U) Link Processing Configuration

(U) The nominal data rate of each link will be the product of the number of carriers assigned to the link and the nominal carrier data rate.

(U) Subject to aggregate rate limits and the need to process an NTR signal, the link processing shall be configurable to support the following: [1MOD-55]

(U) Configuration selections for each link shall be independent of the other links. [1MOD-59]

(U) Transmit/receive link asymmetry shall be allowed. [1MOD-60]

(U) It shall be possible to activate or de-activate individual links without affecting other active links, provided the link and the network are configured to avoid interference. [1MOD-61]

(U) It shall be possible to enable or disable hopping of individual links without affecting other active links, provided the link and the network are configured to avoid interference. [1MOD-62]

(U) Carrier Processing

(U) The modem provides the turbo encoding/decoding, interleaving/deinterleaving, frame generation/synchronization, matched transmit/receive filtering, and transmit/receive IF signal center frequency selection (tuning) functions necessary to support 12 transmit and 12 receive carriers (see Figure 3.1.1.2-1).

Figure 3.1.1.2-1 (U) Carrier Processing

(U) Transmit Carrier Processing

(U) Each transmit carrier processing chain shall accept a data input, perform the subsequent processing necessary to generate a modulated IF output, and provide the tuning to control the carrier center frequency. [1MOD-68]

(U) Receive Carrier Processing

(U) Each receive carrier processing chain shall provide the frequency tuning necessary to select the frequency of the desired IF input, demodulate the IF input, and perform the subsequent processing necessary to reproduce the data input from the distant end. [1MOD-70]

(U) Carrier Processing Parameter Selection

(U) The output power of each transmit carrier and the center frequency of each transmit and receive carrier shall be individually configurable regardless of link assignment. [1MOD-72]

(U) The nominal data rate, interleaver or deinterleaver depth, hopping state, and modulation type selections for all carriers assigned to any multi-carrier link shall be identical. [1MOD-73]

(U) The Turbo encoding or decoding rate for each carrier shall be selected automatically as a function of the modulation type as shown in Table 3.1.1.2.3‑1. [1MOD-74]

(U) The nominal carrier data rate choices shall be as shown in Table 3.1.1.2.3‑1. [1MOD-75] Table 3.1.1.2.3‑1 (U) Turbo Code Rates and Nominal Carrier Data Rates Associated With Each Modulation Type

(Kbps)

Reserved

(U) IF processing

(U) The modem shall support all carriers via a single IF output interface (Transmit IF) and a single IF input interface (Receive IF) with the host terminal. [1MOD-92]

(U) The transmit IF interface shall support all transmit carriers simultaneously. [1MOD-93]

(U) The receive IF interface shall support all receive carriers simultaneously. [1MOD-1010]

(U) The IF operating range shall be 950 to 2000 MHz. [1MOD-96]

(U) The transmit and receive IF interfaces each shall be programmable to operate in selectable 500 MHz wide tuning bands within the IF operating range. [1MOD-890]

(U) The center frequencies of the transmit and receive tuning bands shall be independently selectable in 2.5 MHz increments or less. All transmit carriers must operate within the selected transmit tuning band, and all receive carriers must operate within the selected receive tuning band. [1MOD-97]

(U) If transmission is enabled, the user shall be warned that a requested change to the Tx tuning band will disable transmission. [1MOD-1036]

(U) Transmission shall be disabled upon confirmation by the user of a change to the Tx tuning band. [1MOD-1037]

(U) Timing and Frequency References

(U) Each modem in a network shall receive a 5/10 MHz frequency reference as well as 1 PPS and IRIG-B timing reference inputs from local external time and frequency reference devices. [1MOD-101] Reserved

(U) Network Timing

(U) If the modem and system to which it is connected is configured to receive one of its own carriers as the Network Timing Reference (NTR), the modem shall establish its transmit timing as necessary to acquire the NTR. [1MOD-107]

(U) After self-acquisition of the NTR, the modem shall maintain its transmit timing as necessary to support NTR acquisition and orthogonal frequency hopping by the modems in the network. [1MOD-108]

(U) If the modem and system to which it is connected are configured to use another modem’s carrier as its NTR signal, the modem shall be capable of acquiring the NTR. [1MOD-109]

(U) After acquisition of the NTR by using another modem's carrier, the modem shall maintain timing alignment of its transmit carriers as necessary to support orthogonal frequency hopping and establishment of links with the assigned distant end terminal(s). [1MOD-110]

(U) It shall be possible to assign the NTR function to any receive carrier processing chain. [1MOD-111]

(U) With the exception of receive self-loop, the communications capabilities of a receive carrier processing chain shall be retained if the NTR function is assigned to it. [1MOD-112]

(U) If the carrier receiving the NTR loses sync, the modem shall use the next receive carrier in devolution order that is in sync as the NTR. [1MOD-113]

(U) The devolution scheme shall allow for a minimum of four automated devolutions. [1MOD-1023]

(U) If sync is restored with a higher priority receive carrier, the modem shall use the higher priority receive carrier as the NTR. [1MOD-114]

(U) Frequency Hopping (U//FOUO) Each BPSK, QPSK, or 8PSK modulated link shall be capable of hop-in-place or frequency hopped operation. [1MOD-120] (U//FOUO) The hopping rate shall be configurable to either 1024 or 2048 hops per second. [1MOD-121]

(U) Frequency Hopped Operation

(U) The frequency hopping shall be time-synchronized. [1MOD-123]

(U) The frequency hopping shall be TRANSEC protected in a manner that supports orthogonal frequency hopping (OFH). [1MOD-1016]

(U) The modem transmit configuration inputs shall be used to allocate up to two sub-bands of the transmit IF tuning band for hopping operation. [1MOD-124]

(U) Each transmit carrier with hopping enabled shall use only one allocated sub-band for hopping operation. [1MOD-125]

(U) The modem receive configuration inputs shall be used to allocate up to two sub-bands of the receive IF tuning band for hopping operation. [1MOD-126]

(U) Each receive carrier with hopping enabled shall use only one allocated sub-band for hopping operation. [1MOD-127] Note that all the carriers assigned to the same link must also be assigned to the same hopping sub-band.

(U) Frequency Hopping Bandwidth

(U) The modem shall be capable of spread-spectrum operation using frequency hopping over a single contiguous programmable range of frequencies. [1MOD-129]

(U) The hopping bandwidth (BH) is determined by modem configuration inputs that establish the maximum and minimum center frequency limits of the hopped carrier signal(s). BH is the difference between the maximum and minimum center frequency limits (see Figure 3.1.1.6.2-1 and Figure 3.1.1.6.2-2). The spread-spectrum bandwidth (BSS) of each hopped carrier equals the sum of BH and RS, where RS is the carrier symbol rate.

(U) It also shall be possible to configure the modem such that the overall frequency hopping range includes regions from which the hopping signals are excluded (exclusion regions). [1MOD-131]

(U) It shall be possible to specify up to at least 12 exclusion regions. [1MOD-132]

(U) The result of including one or more exclusion regions is a hopping band consisting of multiple segments, each with its own minimum and maximum center frequency limits. The hopping bandwidth in this case is the total hopping bandwidth of the segments plus (N x RS), where N is the number of segments.

(U) The frequency of the exclusion regions shall be programmable in 100 Hz steps or less. [1MOD-133]

Figure 3.1.1.6.2-1 (U) Relationships Between Bandwidth of PSK Modulated Carrier, Hopping Bandwidth, and Spread-Spectrum Bandwidth

Figure 3.1.1.6.2-2 (U) Basis of Determination of the Spread-Spectrum Bandwidth of a Hopping Band that Includes Exclusion Regions

(U) Seamless Modem Configuration Changes

(U) A configuration change that is implemented with no loss of packet data is considered to be “seamless”.

(U) The modem shall support the ability to synchronize configuration changes at both ends of any packet data link as necessary to implement seamless configuration changes, provided the change parameters are chosen to avoid signal interference. [1MOD-140]

(U) The modem shall support the following seamless changes while operating with all hop-in-place links, all hopping links, or a mixture of hop-in-place and hopping links: [1MOD-141]

a. (U) [shall] Increase of link interleaver/deinterleaver delay settings [1MOD-966]

b. (U) [shall] Reassignment of fixed IF center frequencies of hop-in-place carriers [1MOD-143]

c. (U) [shall] Reassignment of relative IF center frequencies of hopping carriers [1MOD-144]

d. (U) [shall] Hop-in-place to hopping operation and vice versa for any or all links [1MOD-145]

e. (U) [shall] Modification of the transmit or receive hopping sub-band [1MOD-146]

f. (U) [shall] Link data rate in increments of one or more carriers [1MOD-147]

g. (U) [shall] Simultaneous link data rate and modulation format change such that the modulation symbol rate remains unchanged (e.g., one 8PSK carrier @ 4 Mb/s to one BPSK carrier @ 1 Mb/s) [1MOD-148]

h. (U) [shall] Simultaneous change of number of link carriers and modulation format such that the link data rate remains unchanged (e.g., one 8PSK carrier @ 4 Mb/s to four BPSK carriers @ 1 Mb/s) [1MOD-149]

(U) Functional Capabilities

(U) Built-in-Test (BIT) Capabilities

(U) Built-in test (BIT) capabilities shall be provided as necessary to support online fault/status monitoring and offline fault detection/diagnostic functions. [1MOD-152]

(U) BIT circuitry shall be provided as necessary to support the required BIT functions without reliance on external test equipment unless specified otherwise. [1MOD-153]

(U) Online Built-in-Test (BIT)

(U) The modem shall provide a continuously operating online fault/status monitoring function that detects fault conditions and modem hardware failures. [1MOD-155]

(U) Within 2 seconds of detection of a fault condition or hardware failure, the modem shall disable the TX IF output. [1MOD-157]

(U) An indication shall be provided to the Modem Status and Control Interface and displayed via the modem’s Local Operator Interface when a fault is recognized. [1MOD-158]

(U) Indications of the modem’s overall status shall be provided to the Modem Status and Control Interface and to the modem’s Local Operator Interface. [1MOD-159]

(U) Indications of the status of each link supported by the modem shall be provided to the Modem Status and Control Interface and displayed via the modem’s Local Operator Interface. [1MOD-160]

(U) Indications of the performance of each link received by the modem shall be provided to the Modem Status and Control Interface and displayed via the modem’s Local Operator Interface. [1MOD-161]

(U) Offline Fault Detection and Diagnostics

(U) The modem shall provide an offline fault detection and diagnostics function to assist with offline modem diagnostics, repair, maintenance and testing. [1MOD-163]

(U) The modem shall provide the ability to control and monitor the offline fault detection and diagnostics function via the Modem Status and Control Interface or the modem’s Local Operator Interface. [1MOD-164]

(U) The modem shall identify failures to the Line Replaceable Unit (LRU) with a 75% probability of detection. [1MOD-166]

(U) The modem shall provide a test capability to select an unmodulated (i.e., CW) IF output. [1MOD-167]

(U) The modem shall provide an IF loopback test mode to allow the modem to receive its transmit signal. [1MOD-169]

(U) The modem shall provide the ability to produce simultaneous independent BER measurements for up to twelve (12) independently configured carrier processing chains. [1MOD-172]

(U) The modem shall provide a notification if communication will be disrupted as a result of a requested configuration change or test. [1MOD-173]

(U) Configuration Retention

(U) Upon power-up or after loss of power, the AS/AJ Modem shall return to the previous configuration without manual re-entry of the configuration settings. [1MOD-175]

(U) Upon power-up or after loss of power, the IF output shall remain disabled until commanded to turn on. [1MOD-176]

(U) TRANSEC

(U) The KGV-90 will provide TRANSEC support to the modem.

(U) Spectral Inversion

(U) The modem shall support packet communications regardless of the mix of IF transmit and receive tuning bands involved provided only non-inverting up/down converters are used in the signal path. [1MOD-195]

(U) Information Assurance

(U) The modem shall be tested against the Oracle JRE 8 Unix Security Technical Implementation Guide (STIG) Version 1, Release 3.. [1MOD-961]

(U) The modem shall be tested against the Red Hat Linux 6 STIG Version 1, Release 21. [1MOD-1028]

(U) The STIGs are defined at the Information Assurance Support Environment (IASE) website.

(U) Performance Reserved Reserved

(U) Error Rate

(U) The energy per bit (Eb) of the signals that support data packets refer to carrier data bits and is based on nominal carrier data rate (see Figure 3.1.3.3-1).

(U//FOUO) The energy per bit to noise spectral density ratio (Eb/N0) of these signals as measured at the modem IF input is used to define the packet error rate (PER) performance when operating with AWGN only or with AWGN and fading as defined in Appendix B of A3344693.

(U) The term Eb /(N0 + PJ/BSS), where PJ is the jammer power at the IF input and BSS is the spread spectrum bandwidth, is used to define the packet error rate performance when operating with jamming.

(U) In either case, Eb will be corrected using the formula shown in Figure 3.1.3.3-1 to account for the additional energy required to support overhead symbols included in the signal. For hopped signals, the number of guard symbols should be set to zero.

(U) An Ethernet payload size of 188 bytes should be used to determine PER.

(U) The modem shall be capable of spreading the carrier signal spectra over a range of up to 500 MHz. [1MOD-232]

Figure 3.1.3.3-1 (U) Calculation of Overhead Correction Factor

(U) Carrier Performance with AWGN only

(U) The average BER performance at bit error rates ≤ 1.00E-1 shall be within 1 dB of that shown in Figure 3.1.3.3.1-1 for non-hopped BPSK, QPSK, or 8PSK modulated carriers or hopped BPSK, QPSK, or 8PSK carriers operating with AWGN, with no fading, with no jamming and with an IF offset within + 3.5 KHz (including Doppler). [1MOD-241]

(U) The average BER observed over an interval of 24 hours shall be ≤ 1.00E-8 for a signal operating at 2.4 dB (BPSK or QPSK) or 5.4 dB (8PSK) for a non-hopped BPSK, QPSK, or 8PSK modulated carriers or hopped BPSK, QPSK, or 8PSK carriers operating with AWGN, with no fading, with no jamming, and with an IF offset within + 3.5 KHz (including Doppler). [1MOD-242]

(U) For operation with AWGN only, the average PER performance at packet error rates < 1.00E-01 shall be within 1 dB of that shown in Figure 3.1.3.3.1-2 for a non-hopped BPSK, QPSK, or 8PSK modulated carriers or hopped BPSK, QPSK, or 8PSK carriers operating with AWGN, with no fading, with no jamming, and with an IF offset within + 3.5 KHz (including Doppler) [1MOD-987]

(U) See Appendix B for the data points used to generate the Figure 3.1.3.3.1-1.

Figure 3.1.3.3.1-1 (U) Reference Curve for BER Performance with AWGN Only

Figure 3.1.3.3.1-2 (U) Reference Curves for PER Performance with AWGN Only or AWGN with Jamming

(U) Carrier Performance with Jamming (U//FOUO) For operation with AWGN and jamming, the average PER performance with a worst case jammer type at error rates ≤ 1.00E-1 and ≥ (TBD-988A) shall be within 2.2 dB of the appropriate reference curve in Figure 3.1.3.3.1-2 for frequency hopped BPSK, QPSK, or 8PSK modulated carriers with an IF offset within + 3.5 KHz (including Doppler). [1MOD-988]

(U) Carrier Performance with Fading

(U) For operation with AWGN and fading, the average link PER performance at error rates < 1.00E-01 shall be within the limits given in Table 3.1.3.3.3-1 when compared to the appropriate reference curve in Figure 3.1.3.3.3-1 for frequency hopped or non-frequency hopped BPSK or QPSK modulated carriers with an IF offset within + 3.5 KHz (including Doppler). [1MOD-989]

(U) See Appendix B for the data points used to generate Figure 3.1.3.3.3-1.

Table 3.1.3.3.3-1 (U) Maximum Allowable Deviation from Reference Curves

Figure 3.1.3.3.3-1 (U) Reference Curves for PER Performance with AWGN and Fading, or with AWGN, Fading, and Jamming

(U) Carrier Performance with Jamming and Fading (U//FOUO) The average PER performance with a worst case jammer type at message error rates ≤ 1.00E-1 shall be within the limits consisting of the values in Table 3.1.3.3.3-1 plus 10 dB when compared to the appropriate reference curve in Figure 3.1.3.3.3-1 for frequency hopped BPSK or QPSK modulated carriers operating with AWGN, with fading, with jamming, and with an IF offset within + 3.5 KHz (including Doppler). [1MOD-990]

(U) Link Performance

(U) The modem shall support Ethernet frames consisting of an Ethernet payload of 42 to 1500 bytes, 14 byte header, 4 byte CRC, and optional 4 byte VLAN tag. [1MOD-258] Reserved

(U) Link Processing Delay and Jitter

(U) The modem end-to-end link processing delay is defined as the time from inserting a packet at the Ethernet interface to receiving the packet at the Ethernet interface while operating in an IF loopback configuration.

(U) The modem end-to-end link processing delay of any Ethernet frame with no interleaver/deinterleaver delay and without congestion shall be in accordance with Table 3.1.3.4.2-1. Note that the maximum delay values in Table 3.1.3.4.2-1 are inclusive of the peak to peak jitter. [1MOD-264]

(U) The modem end-to-end link peak to peak jitter of any Ethernet frame with no interleaver/deinterleaver delay and without congestion shall be in accordance with Table 3.1.3.4.2-1. [1MOD-1031] Table 3.1.3.4.2-1 (U) Performance Thresholds

Jitter (ms)

(U) Information/Traffic Throughput Rate (ITR)

(U) Information/Traffic Throughput Rate (ITR) is the maximum rate that Ethernet payload traffic can be transmitted over the modem.

(U) The ITR is presented as a percentage of the nominal link rate and shall be no less than shown in Table 3.1.3.4.3-1. For example, if using a single link with two carriers at nominal carrier rates of 1024 Kbps, the nominal link rate is 2*1024 = 2048 Kbps. With an average Ethernet payload size of 188 Bytes, the ITR is greater than 2048 * 85% ≈ 1740 Kbps. [1MOD-269] Table 3.1.3.4.3-1 (U) ITR as a Percentage of Nominal Link Rate

(U) Acquisition

Reserved

(U) NTR Signal Acquisition (U//FOUO) The modem shall synchronize to the pilot symbols of an NTR signal applied to the IF input, either looped back from itself through the satellite or transmitted through the satellite by another modem. [1MOD-290] (U//FOUO) The modem shall support NTR signal synchronization without any satellite range or Doppler information. [1MOD-291] (U//FOUO) The synchronization search range shall include the range uncertainty for satellites with inclinations < 7° and a leap second uncertainty of + 2 seconds. [1MOD-292] (U//FOUO) The probability shall be ≥ 90% that the interval between application of the NTR signal to the modem IF input and modem synchronization is in accordance with Appendix A of A3344693. [1MOD-293] (U//FOUO) These requirements for NTR Signal acquisition shall apply with AWGN only, with AWGN and fading, with AWGN and jamming, and with AWGN and fading plus jamming. [1MOD-294] (U//FOUO) The NTR signal acquisition requirement will be met under the following conditions:

a. (U//FOUO) Data rate: any specified data rate

b. (U//FOUO) Modulation: any specified modulation

c. (U//FOUO) IF center frequency offset: within + 3.5 KHz (including Doppler)

d. (U//FOUO) AWGN: with in all cases

e. (U//FOUO) Fading: with or without (BPSK or QPSK only)

f. (U//FOUO) Jamming: with or without (BPSK, QPSK, 8PSK)

g. (U//FOUO) Jamming plus fading: with or without (BPSK or QPSK only)

h. (U//FOUO) Eb/N0 or Eb/(N0 + PJ/BSS) for BPSK or QPSK: 3 dB (corrected using the formula in Figure 3.1.3.3-1)

i. (U//FOUO) Eb/N0 or Eb/(N0 + PJ/BSS) for 8PSK: 6 dB (corrected using the formula in Figure 3.1.3.3-1)

(U) Circuit Establishment (U//FOUO) Establishment of any of the circuits that support data packets must be preceded by acquisition of an NTR signal. The NTR signal may be transmitted over the satellite and looped back as in the case of the modem acting as a timing master or transmitted over the satellite from another modem as in all other cases.

(U//FOUO) Circuit establishment time is defined as the interval between application or reapplication of a single or multi-carrier signal to the modem IF input and appearance of data at the associated packet output at a packet error rate consistent with the signal power, signal path perturbations, and interference.

(U//FOUO) The probability shall be ≥ 90% that the circuit establishment time in excess of the selected interleaver delay is less than the maximum values shown in Table 3.1.3.5.4-1 for any specified data rate. [1MOD-308] (U//FOUO) All Eb/N0 and Eb/(N0 + PJ/BSS) values will be corrected using the formula in Figure 3.1.3.3-1 to account for the losses resulting from overhead symbols intentionally inserted into the modulated signals.

Table 3.1.3.5.4-1 (U//FOUO) Circuit Establishment Times

Eb/N0 > 6 dB 8PSK

*Eb/(N0 + PJ/BSS) > 6 dB 8PSK

*Greater of specified value or value resulting in PER < 1.00E-2.

(U) Sudden Delay Syndrome

(U) The probability of restoring packet communication after a sudden delay event shall be ≥ 90% when the Eb/No prior to the event is ≥13 dB (corrected using the formula in Figure 3.1.3.3-1). [1MOD-325]

(U) The event will include time varying signal attenuation sufficient to interrupt communications accompanied by a sudden change in signal path delay, time varying Doppler, and the onset of fast fading as described in Appendix B of A3344693.

(U) Network Timing

(U) Network Timing Accuracy

(U) All modems shall adjust the timing of all their transmit carriers such that the timing of each when observed at its distant end is aligned with the NTR within 6 µsec RMS. [1MOD-329]

(U) Loss of 1 PPS Input

(U) The modem shall maintain the ability to function (as defined in paragraph on Loss of Timing Reference, para. 3.1.3.8.4) for at least 24 hours after loss of the 1 PPS reference input signal. [1MOD-331]

(U) The modem shall automatically and seamlessly adapt to the return of the 1 PPS reference input signal if reapplied within the 24 hour period. [1MOD-332]

(U) Loss of NTR Signal (U//FOUO) The modem shall maintain the ability to function for at least 24 hours after loss of the NTR carrier signal, provided the modem has been tracking the NTR signal for at least 24 hours prior to the outage and assuming the satellite is not performing station-keeping adjustments. [1MOD-334] (U//FOUO) The modem shall automatically synchronize and seamlessly adapt to the return of the NTR input signal if reapplied within the 24 hour period. [1MOD-335]

(U) Loss of Timing Reference Inputs (U//FOUO) The modem shall retain the ability to function when the 1 PPS timing signal and the NTR timing signal are lost provided the modem has been tracking the NTR signal for at least 24 hours prior to the outage and the satellite is not performing station-keeping adjustments. [1MOD-116] (U//FOUO) Ability to function is defined as the ability to

· maintain network timing accuracy (Network Timing Accuracy, para. 3.1.3.8.1)

· execute seamless or non-seamless configuration changes

· provide the required error rate performance.

The definition of ability to function excludes execution of initial NTR acquisition.

(U) Loss of IRIG Input

(U) The modem shall use the IRIG-B input to establish the time of day whenever a self-test is commanded. [1MOD-337]

(U) Presence of the IRIG-B input shall be required only when the modem is executing a self-test. [1MOD-338]

(U) Interleaver/Deinterleaver Delay

(U) The interleaver/deinterleaver delay shall be programmable from 0 to at least 12 seconds with a resolution of 100 milliseconds or less. [1MOD-341]

(U) Interfaces

(U) Reference Signal Interfaces External Frequency Reference

(U) The modem shall derive its internal reference frequencies from an externally generated 5 or 10 MHz frequency reference signal. [1MOD-344]

(U) The modem shall automatically detect the reference frequency at power up and adjust operation accordingly. [1MOD-345]

(U) If the external frequency reference is lost for more than 5 minutes, the modem shall declare a fault condition. [1MOD-347]

(U) If the external frequency reference is re-applied after a loss exceeding 5 minutes, the modem shall be capable of responding to commands as necessary to restore operation without cycling power. [1MOD-348]

(U) 5/10 MHz Reference Input Characteristics

(U) The modem shall meet all performance requirements when provided 5 MHz or 10 MHz frequency reference inputs with the following characteristics: [1MOD-350]

a. (U) Waveform: Sine wave

b. (U) Frequency: 5 or 10 MHz

c. (U) Operating level: +13 dBm ±3 dB, into 50 ohms

d. (U) Phase noise in 1 Hz bandwidth: as shown in Table 3.2.1.1.1-1

e. (U) Accuracy: ±1.0E-11

(U) The modem shall have the following frequency reference input port characteristics: [1MOD-356]

a. (U) [shall] VSWR: ≤ 1.5:1 at 5 and 10 MHz [1MOD-357]

b. (U) [shall] Non-Damage Level: +20 dBm continuous [1MOD-358]

c. (U) [shall] Impedance: 50 Ohms [1MOD-359]

d. (U) [shall] Connector: Type SMA female, located on the front panel. [1MOD-360] Table 3.2.1.1.1-1 (U) Reference Signal Phase Noise

Internal Frequency Reference When the modem's external frequency reference is not available, an internal frequency reference shall keep the IF output carrier frequency stable to within 1 × 10−8 per day without frequency source adjustments. [1MOD-994]

(U) 1 PPS Reference Input Characteristics

(U) The modem shall meet all performance requirements when provided a 1 PPS signal with the following characteristics: [1MOD-364]

a. (U) Frequency: 1 Hz

b. (U) Accuracy: ±1 µsec relative to coordinated universal time (UTC) when referenced to the rising edge of the pulse.

c. (U) Level: +2.4 to +5.0 V when true, 0.0 to +0.4 V when false, into 50 ohms

d. (U) Width: 20 s + 1s

e. (U) Rise time: < 50 nanoseconds (ns), 10% to 90%

f. (U) Fall time: < 2 s, 90% to 10%

g. (U) Jitter, pulse-to-pulse: < 5 ns, rms

h. (U) Output impedance: 50 ohms + 25%

(U) The modem shall have the following 1 PPS Reference input port characteristics: [1MOD-373]

a. (U) [shall] Input impedance: 50 ohms + 25% [1MOD-374]

b. (U) [shall] Connector: Type micro USB located on the front panel. See Appendix C for pinouts. [1MOD-375]

(U) IRIG Reference Input Characteristics

(U) The modem shall meet all performance requirements when provided an IRIG time code signal IAW IRIG 200-04 with the following characteristics: [1MOD-377]

a. (U) Format: IRIG-B000 (pulse width code)

b. (U) Level: +2.4 to +5.0 V when true, 0.0 to +0.4 V when false, into 50 ohms

c. (U) Rise time: ≤ 1 s, 10% to 90%

d. (U) Jitter, pulse to pulse: ≤ 200 ns max

e. (U) Output impedance: 50 ohms + 25%

(U) The modem shall have the following IRIG Time Reference input port characteristics: [1MOD-383]

a. (U) [shall] Input impedance: 50 ohms + 25% [1MOD-384]

b. (U) [shall] Connector: Type micro USB located on the front panel. See Appendix C for pinouts. [1MOD-385]

(U) Intermediate Frequency (IF) Output

(U) Output Frequency

(U) The modem shall operate with an IF output within the IF operating range. [1MOD-388]

(U) The frequency of the IF carrier output for each carrier shall be programmable in 100 Hz steps or less. [1MOD-391]

(U) Output Stability

(U) The frequency stability of the IF carriers shall be the same as the external standard frequency stability. [1MOD-393]

(U) Output Accuracy

(U) The IF carrier frequency shall be within 0.1 ppm of the selected frequency, without a warm-up period. [1MOD-395]

(U) Spectral Confinement

(U) The IF output for each non-hopped packet carrier shall meet the power spectral density confinement mask shown on Figure 3.2.4.4-1. [1MOD-397]

(U) The IF output for each hopped packet carrier shall meet the power spectral density confinement mask shown on Figure 3.2.4.4-1 for frequencies below the minimum center frequency limit of the hopping sub-band (or segment) and above the maximum center frequency limit of the hopping sub-band (or segment). [1MOD-398]

(U) Modulation symbol rates for the carriers shall be as shown in Table 3.2.4.4-1 and Table 3.2.4.4-2. [1MOD-400]

(U) These spectral confinement requirements will be met with the output terminated into a 50 ohm load having a VSWR ≤ 1.5:1 measured with a single carrier at maximum transmit power for symbol rates below 1 Msym/sec.

(U) For symbol rates above 1 Msym/sec, the outer mask spec points (-61.5 dBr points) shall be increased by 10*log10(Rs/1e6) to make the outer mask points equivalent to the phase noise mask. [1MOD-402]

(U) The mask shall only apply to the extent allowable at the phase noise floor. [1MOD-403]

Figure 3.2.4.4-1 (U) Modulator Output Power Spectral Density Limit Mask Table 3.2.4.4-1 (U) BPSK Carrier Modulation Symbol Rates

Rate 1/2 Coded BPSK Symbol Rate (Ksym/s)

Table 3.2.4.4-2 (U) QPSK& 8PSK Carrier Modulation Symbol Rates

Rate 1/2 Coded QPSK Symbol Rate (Ksym/s)

Rate 2/3 Coded 8PSK Symbol Rate (Ksym/s)

(U) Phase Noise

(U) The IF output phase noise will be tested with a single carrier in the CW mode.

(U) Continuous Component The modem IF output single sideband phase noise shall not exceed the mask shown in 3.2.4.5.1-1 unless the SSB phase noise meets the conditions a) and b) below: [1MOD-415]

a) If the mask in Figure 3.2.4.5.1-1 is exceeded, then for all symbol rates supported by the modem, the following shall be true: [1MOD-995]

(1) The measured SSB RMS phase noise should be integrated over the limits of 0.0005 Rs to 0.5Rs away from the carrier center frequency.

(2) The spectral mask shown in Figure 3.2.4.5.1-1 should be integrated over the same limits, 0.0005 Rs to 0.5Rs away from the carrier center frequency

(3) The integrated measured phase noise shall not exceed the integrated phase noise limit mask. [1MOD-998]

b) If the mask in Figure 3.2.4.5.1-1 is exceeded, for all symbol rates supported by the modem, the calculated SSB continuous component RMS phase noise, integrated over the limits of 0.0005 Rs to 0.5 Rs, shall not exceed 2.25° given that the modem's highest order modulation format is 8-PSK. [1MOD-999]

Figure 3.2.4.5.1-1 (U) Phase Noise Spectral Density Limit Mask

(U) Discrete Component

(U) The following requirements shall apply when measuring the phase noise spectral density: [1MOD-423]

a. (U) AC power line. The fundamental and each spurious component at the alternating current (AC) line frequency shall be equal to or less than -36 dBc. [1MOD-424]

b. (U) Single sideband. The single sideband sum (added on a power basis) of all other individual spurious components shall be equal to or less than -42 dBc. [1MOD-425]

(U) Output Power Control Range, Step Size and Accuracy

(U) The absolute accuracy of each modem IF output carrier power shall be within 1.0 dB of the selected value. [1MOD-427]

(U) The relative accuracy of the modem IF output carrier power associated with the smallest step increment shall be within 0.1 dB. [1MOD-428]

(U) The modem IF output carrier power minimum step size shall not exceed 0.25 dB. [1MOD-429]

(U) When a power change is initiated, the power shall not deviate more than 0.5 dB from monotonic during the transition. [1MOD-430]

(U) When a power change is initiated, it shall not induce burst errors into the controlled carrier’s bit stream. [1MOD-1017]

(U) When a power change is initiated, it shall not induce burst errors into any other transmit carrier associated with the modem. [1MOD-1018]

(U) When a power change is initiated, it shall not induce burst errors into an adjacent carrier’s bit stream (adjacent carrier spaced at 1.2 Rs). [1MOD-1020]

(U) The modem IF output power shall be adjustable over the range from 0 to -40 dBm. [1MOD-431]

(U) The requirements for absolute accuracy, relative accuracy, and monotonicity shall apply only when the sum of all carriers is less than or equal to 0 dBm. [1MOD-432]

(U) When the transmission carrier output is set to OFF, no signal present at the output, from 0 to 4,000 MHz, shall be greater than −70 dBm across any 3 MHz bandwidth nor greater than −80 dBm across any 30 kHz bandwidth. [1MOD-433]

(U) IF Output Port Characteristics

(U) The modem shall provide an IF output port with the following characteristics: [1MOD-435]

a. (U) [shall] Impedance: 50 Ohms [1MOD-436]

b. (U) [shall] VSWR: 2.0:1 maximum over the supported tunable range when operating in the IF band. [1MOD-438]

c. (U) [shall] Connector: Type SMA female, located on front panel. [1MOD-439]

(U) Spurious Emissions

(U) At the modem's IF output, the spurious emission power in any 10-kHz bandwidth, exceeding -70 dBm, shall be controlled relative to total modulated carrier power shown in the formula in Figure 3.2.4.8-1. Note that the requirement excludes ±1.0Rs centered on the carrier. [1MOD-441]

Where:

is the threshold corresponding to a BER of 10-10 for the most spectrally efficient combination of modulation and coding supported by the modem;

If the threshold (or ) is not specified for a BER of 10-10, then the threshold for the next higher specified BER may be used;

The expression bounding is limited above by -51 dBc and below by -70 dBc.

Figure 3.2.4.8-1: (U) Spurious Emissions

(U) Harmonics

(U) At the modem's IF output, the power of any transmission carrier harmonic within the tunable band exceeding -70 dBm shall be controlled, relative to total modulated carrier power, according to the formula in Figure 3.2.4.9-1. [1MOD-443]

Where:

is as defined in section 5.5.5.3;

The expression bounding is limited above by -51 dBc and below by -70 dBc.

Figure 3.2.4.9-1: (U) Harmonics in the Tunable Band

(U) At the modem's IF output, the power of any transmission carrier harmonic outside of the tunable band shall not exceed -70 dBc. [1MOD-977]

(U) Isolation

(U) The modulator-to-demodulator isolation shall be such that with the demodulator operating with a distant modulator, there is less than 0.2 dB change in measured demodulator performance at 1.00E-5 BER from specified BER with the local modulator operating at any frequency and/or output power level, compared to the demodulator performance with the local modulator turned off. [1MOD-445] Transmission Thermal Noise The modem's IF output thermal noise density shall not exceed the greater of −135 dBm/Hz or −135 dBc/Hz over the full IF band. [1MOD-1003]

(U) Intermediate Frequency (IF) Input

(U) Carrier Frequency

(U) The modem shall operate with an IF input within the IF operating range. [1MOD-448]

(U) The frequency of the IF carrier input for each circuit shall be programmable in 100 Hz steps or less. [1MOD-451]

(U) Frequency Uncertainty

(U) The modem shall be able to acquire and demodulate signal carriers that are within ± 3.5 KHz (including Doppler) of the selected frequency. [1MOD-453]

(U) Desired Carrier

(U) The modem shall operate with a minimum carrier level defined by the formula in Figure 3.2.5.3-1. [1MOD-978] Pmin = -113 dBm/Hz + Es/N0 + 10 log Rs

Where:

Es/N0 (in dB) is the specified performance value for a BER of 1 x 10-8 Rs is symbol rate in symbols/second.

Where Es/N0 performance is not specified, then:

Es/N0 = Rd/Rs x Eb/N0 Eb/N0 (in dB) is the specified performance value for BER of 1 x 10 -8.

Rd is data rate in bits/second.

Figure 3.2.5.3-1: (U) Minimum Carrier Level

(U) The modem shall operate with a maximum carrier level defined by the formula in Figure 3.2.5.3-2. [1MOD-981]

Figure 3.2.5.3-2: (U) Maximum Carrier Level

(U) Composite Power

(U) The modem shall maintain its specified AWGN performance at 1.00E-5 BER for a desired carrier that is a single BPSK rate 1/2 Turbo coded carrier under all of the following conditions are met: [1MOD-462]

a. (U) The sum of all carriers within 10 MHz of the desired carrier is ≤ +30 dBc.

b. (U) The sum of all carriers is ≤ +40 dBc.

c. (U) The sum of all carriers is ≤ +10 dBm.

Noise Figure The modem's demodulator noise floor shall be less than -130 dBm/Hz. [1MOD-1005]

(U) Adjacent Carrier Interference

(U) Rs refers to the symbol rate of the desired carrier. The AWGN bit error rate performance when operating in the presence of two adjacent symmetrical carriers spaced at +/- 1.2 * Rs operating with the same modulation, data rate, coding, and power levels of +13 dBc shall be less than 1 dB from the ideal curve. [1MOD-468]

(U) The AWGN bit error rate performance when operating in the presence of two adjacent asymmetrical carriers spaced at +/- 1.8 * Rs at a symbol rate of 2.0 * Rs, and each with a power level of +13 dBc…