VOICE AND AUDIO COMMUNICATIONS

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Draft
Recommendation for

Space Data System
Practices

VOICE

AND AUDIO

COMMUNICATIONS

DRAFT RECOMMENDED PR
ACTICE

CCSDS 000.0
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RED BOOK

May 2005

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AUTHORITY




Issue:

Red Book
,
Issue 0



Date:

October 2008



Location:

Not Applicable



(WHEN THIS RECOMMENDED
PRACTICE
IS FINALIZED, IT WILL CONTAIN
THE FOLLOWI
NG STATEMENT OF AUTHORITY:)

This document has been approved for publication by the Management Council of the
Consultative Committee for Space Data Systems (CCSDS) and represents the consensus
technical agreement of the participating CCSDS Member Agencies.

The procedure for
review and authorization of CCSDS documents is detailed in the
Procedures Manual for the
Consultative Committee for Space Data Systems
, and the record of Agency participation in
the authorization of this document can be obtained from the

CCSDS Secretariat at the
address below.



This document is published and maintained by:


CCSDS Secretariat

Space Communications and Navigation Office, 7L70

Space Operations Mission Directorate

NASA Headquarters

Washington, DC 20546
-
0001, USA


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STATEMENT OF

INTENT

(WHEN THIS RECOMMENDED
PRACTICE
IS FINALIZED, IT WILL CONTAIN
THE FOLLOWING STATEMENT OF INTENT:)

The Consultative Committee for Space Data Systems (CCSDS) is an organization officially
established by the management of its members. The Committee m
eets periodically to address
data systems problems that are common to all participants, and to formulate sound technical
solutions to these problems. Inasmuch as participation in the CCSDS is completely voluntary,
the results of Committee actions are terme
d
Recommend
ation
s
and are not considered
binding on any Agency.

This
Recommended Practice
is issued by, and represents the consensus of, the CCSDS
members.


Endorsement of this
Recommended Practice

is entirely voluntary. Endorsement,
however, indicates th
e following understandings:

o

Whenever a member establishes a CCSDS
-
related
practice
, this
practice should

be in
accord with the relevant
Recommended Practice
. Establishing such a
practice
does not
preclude other provisions which a member may develop.

o

Whenever a member establishes a CCSDS
-
related
practice
, that member will provide
other CCSDS members with the following information:


--

The
practice
itself.


--

The anticipated date of initial operational capability.


--

The ant
icipated duration of operational service.

o

Specific service arrangements shall be made via memoranda of agreement. Neither this
Recommended Practice
nor any ensuing
practice
is a substitute for a memorandum of
agreement.

No later than five years from

its date of issuance, this
Recommended Practice

will be
reviewed by the CCSDS to determine whether it should: (1) remain in effect without change;
(2) be changed to reflect the impact of new technologies, new requirements, or new
directions; or (3) be ret
ired or canceled.

In those instances when a new version of a
Recommended Practice
is issued, existing
CCSDS
-
related member
Practices

and implementations are not negated or deemed to be non
-
CCSDS compatible. It is the responsibility of each member to deter
mine when such
Practices

or implementations are to be modified.


Each member is, however, strongly encouraged to
direct planning for its new
Practices

and implementations towards the later version of the
Recommended
Practice
.

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FOREWORD

[Foreword text speci
fic to this document goes here. The text below is boilerplate.]

Through the process of normal evolution, it is expected that expansion, deletion, or
modification of this document may occur. This
Recommended
Practice

is therefore subject
to CCSDS document

management and change control procedures, which are defined in the
Procedures Manual for the Consultative Committee for Space Data Systems
. Current
versions of CCSDS documents are maintained at the CCSDS Web site:

http://www.ccsds.org/

Questions relating

to the contents or status of this document should be addressed to the
CCSDS Secretariat at the address indicated on page i.

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At time of publication, the active Member and Observer Agencies of the CCSDS were:


Member Agencies




Agenzia Spaziale Italiana (ASI
)/Italy.



British National Space Centre (BNSC)/United Kingdom.



Canadian Space Agency (CSA)/Canada.



Centre National d’Etudes Spatiales (CNES)/France.



China National Space Administration

(CNSA)/People’s Republic of China.



Deutsches Zentrum für Luft
-

und Raumf
ahrt e.V. (DLR)/Germany.



European Space Agency (ESA)/Europe.



Russian
Federal Space Agency

(RFSA)/
Russian Federation.



Instituto Nacional de Pesquisas Espaciais (INPE)/Brazil.



Japan Aerospace Exploration Agency (JAXA)/Japan.



National Aeronautics and Space Ad
ministration (NASA)/USA.


Observer Agencies




Austrian Space Agency (ASA)/Austria.



Belgian Federal Science Policy Office (
B
FSPO)/Belgium.



Central Research Institute of Machine Building (TsNIIMash)/Russian Federation.



Centro Tecnico Aeroespacial (CTA)/Brazil
.



Chinese Academy of
Sciences

(CAS)/China.



Chinese Academy of Space Technology (CAST)/China.



Commonwealth Scientific and Industrial Research Organization (CSIRO)/Australia.



Danish National Space Center (DNSC)/Denmark.



European Organization for the Exploita
tion of Meteorological Satellites
(EUMETSAT)/Europe.



European Telecommunications Satellite Organization (EUTELSAT)/Europe.



Hellenic National Space Committee (HNSC)/Greece.



Indian Space Research Organization (ISRO)/India.



Institute of Space Research (IKI)/R
ussian Federation.



KFKI Research Institute for Particle & Nuclear Physics (KFKI)/Hungary.



Korea Aerospace Research Institute (KARI)/Korea.



CSIR Satellite Applications Centre (CSIR)/Republic of South Africa.



Ministry of Communications (MOC)/Israel.



National

Institute of Information and Communications Technology (NICT)/Japan.



National Oceanic and Atmospheric Administration (NOAA)/USA.



National Space Organization
(NSPO)/Chinese Taipei.



Naval Center for Space Technology

(
NCST
)/USA.



Space and Upper Atmosphere Re
search Commission (SUPARCO)/Pakistan.



Swedish Space Corporation (SSC)/Sweden.



United States Geological Survey (USGS)/USA.

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PREFACE

This document is a draft CCSDS Recommended Practice. Its ‘Red Book’ status indicates that
the CCSDS believes the document to
be technically mature and has released it for formal
review by appropriate technical organizations. As such, its technical contents are not stable,
and several iterations of it may occur in response to comments received during the review
process.

Implemen
ters are cautioned
not

to fabricate any final equipment in accordance with this
document’s technical content.

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DOCUMENT CONTROL


Document

Title

and Issue

Date

Status

CCSDS
000.0
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[Document Title]
,
Draft
Recommended
Practice
,
Issue 0

October
2008

Current

draft











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CONTENTS

Section

Page



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1

INTRODUCTION

1.1

PURPOSE

The Recommended Practice
Voice

and Audio

Communications

specifies the
technolog
ies
,
services and service interfaces

for
voice

and audio
communications

among terrestrial
facilities in support

of the
mission
operations
of
human and robotic space flight
.

1.2

SCOPE

This document details t
he exchange of
voice and audio data
between
terrestrial facilities,
and
between t
errestrial and space borne facilities
.

1.3

APPLICABILITY

Applies to any terrestrial
and space
voice
and audio
communication
s

capability said to be
interoperable through adherence to CCSDS recommended practices

and for use in mission
operations
.

1.4

RATIONALE

Provide recommended practices to promote interoperability and development reuse via p
eer
-
to
-
peer and vertical standardization.

1.5

REFERENCES

The following documents contain provisions which, through reference in this text, constitute
provisions of this Recommended
Practice
. At the time of publication, the editions indicated
were valid. All
documents are subject to revision, and users of this Recommended
Practice
are encouraged to investigate the possibility of applying the most recent editions of the
documents indicated below. The CCSDS Secretariat maintains a register of currently valid
CC
SDS
Documents
.

[Only references required
as part of the
specification are listed in the References subsection.
See
CCSDS A20.0
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2,
CCSDS Publications Manual

(Yellow Book, Issue 2, June 2005)

for
additional information on this subsection.]


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2

OVERVIEW

As a first step in defining best practice in voice and audio
communication

support human
spaceflight, the following are being addressed herein:



The
exchange

of voice
data
among mission operations centers




The exchange of voice data

between mission operations centers and
space borne
vehicles




UHF
e
mergency
and proximity operations
voice
communications



Search and rescue (SAR) voice
communications

[Non
-
normative overview text appears in section 2. See
CCSDS A20.0
-
Y
-
2,
CCSDS
Publications Manual

(Yellow Book, Issue 2, June 2005)

for the contents of section 2.]


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3

VOICE AND AUDIO

COMMUNICATIONS

3.1

INTRODUCTION

Voice and audio communications among space transport vehicles, habitat, rover and Earth

requires the
exchange o
f voice data.

The quality of the voice rendered at the endpoints
reflects the coherent engineering
of the
propagation
of

voice data though the
interface
boundaries

that exists end
-
to
-
end
between

participants in voice communciations
.

The mixed
use of lossy and lossless codec
s through these boundaries
may result in less than desired
voice quality.





3.2

THE E
XCHANGE OF VOICE
DATA

AMONG MISSION OPERAT
IONS
CENTERS

Where voice data primarily consists of voice conferences or voice loops.

Mission Operations Cent
ers, or
MOCs employ
centralized,
high performance, high
availability and high capacity

voice conference systems to provide
voice communications for
flight ope
rations
and support
personnel
.
Th
e required
level of performance is
typically
achieved through
dedicated
TDM (Time Dimension Multiplex) based systems

and dedicated
E1/T1 cabling plants to keysets located in flight control rooms. E1/T1 provides

the necessary
interface to outside voice communications.


In order to bridge
selected voice conferences
among the various control and support
centers
,
the co
mmercial

telecom services
market provides
a
number of options such as leased E1/T1
circuits
, MPLS, ATM and WAN circuits.


The following context diagram illustrates:



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3.2.1

E
1/
T
1

CIRCUIT

Exchanging the voice data associated with a
single voice loop, or voice conference, between
any two
centers is accomplished through leased and dedicated toll quality voice circuits. The
following provide direction in regard to the specific configurations that provide the necessary
level of service.

3.2.1.1

Over
ATM

ATM circuit

3.2.1.2

Over
MPLS

MPLS circuit, where segments are encapsulated in MPLS
; ColCC has experienced clocking
issues with voice from DVIS (analog through T1 channel bank) but the problem does not
appear with MOVE to MOVE integration

3.2.1.3

Over
Circuit E
mulation

T1 or E1 over a WAN circuit through a T1/E1 over IP encapsulation service.

Reword this
sentence

3.2.2

VOIP

Vo
ice Over Internet Protocol
,
where the
originating voice codec
is maintained if possible

through wide area network
links,

an example would be
IP
/UDP/RTP/G.711 or
IP/UDP/RTP/
G.729
.

High performance voice conferencing systems typically are TDM with
G.711

-
law or

-
law voice encoding, re
-
encoding voice data into different VOIP encoding
may be required.

Where possible, v
oice quality should no
t

be sa
crificed
in deference to
bandwidth

usage and

in
this concern

the
end to end configuration must be considered.

L
ossy voice
codecs should be
employed carefully, and voice
e
ncoding should occur only once

(ideally) between end points.
Multiple encode/decode
cycles significantly affects voice quality.

Insert analog: transcoding,
space/ground issue


voice

summation…

Detail why one would choose the lossy or non
-
lossy codec, where and therefore why the selection of codecs exists in this book.

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3.3

THE EXCHANGE OF VOIC
E DATA BETWEEN MISSI
ON OPERATIONS
CENTERS AND SPACE BO
RNE VEHICLES.

The exchange of voice and audio

communications
between vehicles in space and earthbound
MOCs necessarily involves
the satellites and ground stations of
space and deep space
networks
.

It should be noted that
s
pace

transport

vehic
le
s
, habitat
s
,

rover
s, and or space
borne assets
may have the same
communications capabilities so as
to exchange voice data
through
a
common
set of
communications capabilities.


The following context dia
gram illustrates:




3.3.1

VOICE ENCODING:

G.729 AT 8 KHZ

3.3.2

VOICE DATA TRANSPORT

Voice data transport
includes the packet or packaging of voice data within the transport stack.



3.3.2.1

IP/UDP/RTP
/G.729

IP packet oriented transport of voice data.

It is necessary

to configure the header information
so that the receiving entity can process the exchanged data.

3.3.2.2

G.729
frame
s within dedicated virtual channel




Communication protocol or stack containing voice data.
External interface to

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Look CCSDS standards, analyze impact: Virtual Channel.

Probably

not?? Some
value in looking at other CCSDS standards; are there issues with how things are
stacked up? Unique issues with some CCSDS standard asynchronous data issues?

Pink sheet here. This could be follow
-
on work after this MB…



Consider codecs and vo
ice data exchange but stop at the comm. stack for this product.
This leaves vehicle, habitat and rover
comm.

between them, and back to earth. This
also leaves out
satellite

relay because that would be more into the comm. stack.

3.4

UHF EMERGENCY
AND PROXIMIT
Y OPERATIONS
VOICE
COMMUNCIATIONS


3.5

SEARCH AND RESCUE (S
AR) VOICE COMMUNICAT
IONS


[Normative specifications appear in sections 3 throug
h
n
. See
CCSDS A20.0
-
Y
-
2,
CCSDS
Publications Manual

(Yellow Book, Issue 2, June 2005)
.]


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4

SECURITY

4.1

INTRODUCTION

Encryption is part of the comm. layer…

4.2

SECURITY CONCERNS WI
TH RESPECT TO THE CC
SDS DOCUMENT

4.2.1

DATA PRIVACY

Virtual channel assignment

Meta data f
lags

IP/port configuration

4.2.2

DATA INTEGRITY


4.2.3

AUTHENTICATION OF CO
MMUNICATING ENTITIES


4.2.4

CONTROL OF ACCESS TO

RESOURCES


4.2.5

AVAILABILITY OF RESO
URCES


4.2.6

AUDITING OF RESOURCE

USAGE


4.3

POTENTIAL THREATS AN
D ATTACK SCENARIOS


4.4

CONSEQUENCES OF NOT
APPLYING SECURITY TO

THE

TECHNOLOGY



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ANNEX A


[ANNEX TITLE]


[EITHER NORMATIVE OR

INFORMATIVE]

[Annexes contain ancillary information.
Normative

annexes precede informative annexes.
Informative references are placed in an informative annex. See
CCSDS A20.0
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2,
CCSDS
Publications Ma
nual

(Yellow Book, Issue 2, June 2005)

for discussion of the kinds of
material contained in annexes.]