9100-0001-01-OISL-Standard.pdf

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Space Development Agency Optical Intersatellite Link (OISL) Standard

Developed by the

Space Development Agency

Office of the Under Secretary of Defense, Research and Engineering (USD(R&E)) 3030 Defense Pentagon Washington, D.C. 20301

Email: OSD.SDA.Outreach@mail.mil

Date: 6/4/2020

Document ID: 9100-0001-01

This document is a draft of a proposed Space Development Agency Standards Document. As such, this document is subject to revision.

DISTRIBUTION STATEMENT A. Approved for public release: distribution unlimited.

Space Development Agency Optical Intersatellite Link (OISL) Standard

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Revision History Date Version Notes Status

5/1/2020 N/A Draft as issued for Transport Layer T0 RFP

HQ085020R0001

DRAFT

6/5/2020 1 This version incorporates editorial changes only. DRAFT

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Contents Revision History

SDA Draft OISL Standard

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SDA Draft OISL Standard Table 1 presents a notional baseline for interoperable design parameters. This process is expected to be iterative to refine the set of finalized parameters. Many protocol items in Table 1 are noted as “to be defined by PDR”. SDA expects the complete set of selected vendors to have agreed on the basic interoperability requirements by SRR, have defined the first draft of an over-the-air interoperability ICD by PDR, and have reached a second, implementable draft by CDR. SDA acknowledges that the Tranche 0 ICD will not be feature-complete regarding objectives for future tranches.

Table 1 – Draft OISL Standard

Parameter Threshold Objective Notes

A Wavelength: C-band 1553.33 nm (selectable) The center frequency of the optical carrier shall be tunable from 193.1 + n×0.1 THz, where n is an integer ranging from -30 to +30 corresponding to wavelengths in vacuum ranging from 1528.77 nm to 1577.03 nm with 100

GHz channel spacing consistent with ITU-T

G.694.1

ITU-T G.694.1

100GHz channel

N=-1.

The intent is for bidders to support two different frequencies in this range separated by at least 15 nm. The specific two wavelengths will be agreed upon between the winning bidders and SDA after award

(nominally by PDR).

Which wavelength is used for Tx and Rx must be switchable by command on orbit.

B Wavelength: C-band 1536.61 nm (selectable) ITU-T G.694.1

100GHz channel

N=+20

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Polarization Type (LEO SV to LEO SV link)

LHCP Receive (Rx) compatible LHCP Transmit (Tx) See ANSI/IEEE

Standard 149-1979, “IEEE Standard Test

Procedures for

Antennas”. Designs need to be compatible with both polarization-maintaining and non-polarization-maintaining designs.

It is acceptable to lose

3 dB due to mismatch if the threshold data rate is still met.

OISL Switchable TX/RX

Pairing

Yes

TX Power description Each respondent will propose their min and max flux at 1000, 3000, and 5000 km

Government required link margin

3 decibel (dB) Bidders are encouraged to propose a combination of techniques including power, aperture, forward error correction, and other coding techniques to contribute to this required minimum link margin while maintaining interoperability.

Terminal Field of Regard

(FOR) min. & max.

TBD

Modulation Format On-Off Keying (OOK) Non-

Return-to-Zero

(NRZ)

Coding LDPC-based forward error correction (FEC).

To be defined by PDR.

In-flight re-programmability to support evolution from

Tranche 0 experimental implementations to final objective interoperability standards.

Prior art includes

DVB-S2

(BCH+LDPC),

DOCSIS 3.1, 400ZR /

802.3ct, and CCSDS standards but OISLs are a distinct use case from existing standards.

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Bit Error Rate (BER) after

Forward Error Correction

(FEC)

10-6 10-9 SDA desires low

BERs because time-of-flight delays cause high retransmission latencies

Modem Latency 15 ms 5 ms Defined as time from photons at aperture to bits at data interface

Link Training None required. None required. Future higher-performance interoperability standards may require link training to enable higher data rate modes.

Physical Framing Point-to-point link. Includes sequence numbers and automatic repeat request data.

May include modulation/FEC rate signaling and/or management data.

re-programmability to support evolution from

Tranche 0 experimental implementations to final objective interoperability standards.

Prior art includes

IEEE 802.3 and

802.11, 3GPP

(LTE/LTE-A/5G),

DOCSIS 3.1, and various ITU-T and

CCSDS standards but

OISLs are a distinct use case from existing standards and require large (20+ bit) sequence numbers.

Payload Datagram

Encapsulation/Framing

Encapsulates/frames 802.3

Ethernet frames and possibly link management frames.

Supports payload fragmentation/reassembly across physical transmission frames.

re-programmability to support evolution from

Tranche 0 experimental implementations to final objective interoperability standards.

Prior art includes

ITU-T G.7041

Generic Framing

Procedure, CCSDS

Generic Framing

Procedure, and

HLDC

Link management Protocol feature / extension negotiation, error rate reporting, FEC and modulation rate control, tracking data exchange, ranging and synchronization data, future extensibility.

re-programmability to support evolution from

Tranche 0 experimental implementations to final objective interoperability standards.

Prior art includes

3GPP (LTE/LTE-

A/5G), IEEE 802.11,

and CCSDS standards.

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Coding and Modulation Re-programmability

Adaptive Coding and

Modulation (ACM)

TBD @ SRR

OISL terminal-to-terminal timing accuracy

10 nanosecond 1 nanosecond (rms)

OISL timestamping accuracy

10 nanosecond (rms) 1 nanosecond (rms) Path to 0.3 ns (rms)

OISL ranging accuracy 3 m (rms) 30 cm (rms)

OISL range rate accuracy N/A 1 cm / second

Point-ahead capability TBD TBD

Acquisition time 100 sec 10 sec Cold start. Proposers are required to be capable of acquiring without a beacon within the threshold acquisition time.

After selection, SDA will work with selected proposers on options for accelerating acquisition time.

Sun Exclusion Angle +/- 5 deg +/- 3 deg Operation with other bright objects (Earth, Moon, etc.) in the

FOR

User terminal orbital altitude regime

750 – 1250 km