Optical Communications Green Book

Outline

Blue Book for Optical Communications

Physical Layer

Blue Book for Optical Communications

Coding & Synchronization

Green Book for Optical Communications

Concepts and Terminologies

Green Book for Real-Time Weather and

Atmospheric Characterization Data

Green Books are informational, non-normative, supportive documents to Blue/Magenta Books

CCSDSCONCEPTPAPER

MISSION DEPLOYMENT

CCSDSDraftStandard(“Red”, “Pink”)

EXPERIMENTALDEPLOYMENT

Hard Requirement

Hard Requirement Prospective Requirement

CCSDSInformationalReport(“Green”)

CCSDSHistoric(“Silver”)

DECOMMITTEDDEPLOYMENT

CCSDSRecord(“Yellow”)

CCSDSDraftInformational

CCSDSExperimental(“Orange”)

CCSDSDraftPractice(“Red”, “Pink”)

CCSDSProposedStandard(“White”)

NORMATIVE TRACK NON-NORMATIVE TRACK

CCSDSRecommendedPractice(“Magenta”)

CCSDSProposedPractice(“White”)

CCSDSRecommendedStandard(“Blue”)

• CCSDS INFORMATIONAL (GREEN BOOK)

• The “informational” document designation is intended to provide for the timely publication of a very broad range of general information for the CCSDS community.

• Informational documents are often published in support of an experimental specification, a Draft Recommended Standard, or a Recommended Standard.

• They may therefore contain overview or descriptive material, supporting analysis, requirements, descriptions of use, scenarios, etc., which are otherwise inappropriate for the contents of a normative technical specification.

From CCSDS “Boot Camp” presentation, Oct 2012

From CCSDS Optical Communications (OPT) Working Group Concept Paper

Title: Optical Communications Concepts and Terminologies

Document Type: Green Book

Description of Document: This Green Book will define common terminology and atmospheric models to be used in link and pointing budget calculations and define a basic concept of operations, including handovers from one location to the next. For glossary and terminology issues SANA will be consulted in coordination.

Contents of the Green Book:

Terminology Definition Atmospheric Models Link and Pointing Budget Calculation Examples of Concepts of Operations A)

Optical Communication Green Book Writing Philosophy

1. Description of parameters (terms) specified in our Blue Books– For example: Blue book may state requirement for modulation extinction

ration. This green book will provide definition of extinction ratio, how it can be measured, etc

2. Common Atmospheric Models recommended to support optical links selection during preparatory and handover planning

– Utilizing measured atmospheric parameters data defined in Atmospheric Green Book

3. Links Budgets template with an example– Defining common parameters to be used for links budgets generation for

various scenarios– Link Budget Example for one (or few) of the most common links

4. Typical ConOps stages description– Coordinated with ConOps normative specified in Blue Books

Details of Terminology Section

– Physical Layer Terminology• Clock Description (Rate, Jitter, Drift)• Communication Pulse (Shape,

Modulation Format and Rate)• Optical Characteristics (wavelength,

Polarization, Linewidth, etc)– Digital Domain Terminology

• Data Rates• Data Framing• Coding Description • Description of Interleaving Process• In-band Command and Telemetry

Processing

– Performance Metrics• EIRP • PFD • Implementation Penalties • Error Rates

– PAT Terminology• Beacon (configuration,

Spectrum, Power, Modulation)• Pointing (Ephemeris, Scanning)• Acquisition (Spatial, Clock and

Frame)• Tracking (Coarse, Fine)

List below is notional. It will include parameters matching those defined in Blue Books

“This Green Book will define common terminology. … ”

Atmospheric Optical Channel Models

– Measured parameters defined in Atmospheric Green Book are inputs to atmospheric models of this book

– Outputs of atmospheric models directly or indirectly define link budget parameters and support Concept of Operations (Optical Ground Station selection for link, communication data rates, etc.)

– Examples

“This Green Book will define … atmospheric models to be used in link and pointing budget calculations”

Input Statistics Model Type Output

Cloud coverage data CFLOSGround Location and timing selection for required operation

Photometer data Atmospheric Loss Data rates selection

Scintillometers data Turbulence Data rates selection

Photometer data Sky BackgroundGround Location and timing selection for required operation

Link and Pointing Budget Template

Defines common parameters to be used to construct various types of link budgets:

• Antennae Gain• Optical Losses• Transmit Power• Etc

And provides their description

Link Budget example from Optical Link Study Group’s (OLSG) Final Report:

“This Green Book will … be used in link and pointing budget calculations”

ConOps Example– Links Selection (t = t0 – x hours or even days)

• Laser Safety activities• CFLOS and Atmospheric Turbulence• Ephemeris Data Distribution• Elements preparations: performance and connectivity checks, etc)

– Links Establishment (t = t0 – y minutes)• Initialization (Pointing)• Acquisition• Tracking

– Links Operation (t = t0 )• Data Communication• Telemetry Exchange• Handover (scheduled and un-scheduled)• Laser safety interruptions and recovery

– Links termination and post operation (t = t0 + T)• Links Termination• Links Performance Correlation with Atmospheric Statistics/ Atmospheric Models updates • Post Operation Maintenance

t0 – start of communicationT – operation length

“This Green Book will … define a basic concept of operations, including handovers from one location to the next.”