NASA Space Network Ground Segment Sustainment (SGSS) Schedule Request SMWG Boulder, CO 31 October – 4 November 2011 John Pietras GST, Inc

NASA Space Network Ground Segment Sustainment (SGSS)

Schedule Request

SMWG

Boulder, CO

31 October – 4 November 2011

John Pietras

GST, Inc.

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Agenda

Purpose

Background

Approach

Schedule Request Class Diagrams

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Purpose

To describe the (still evolving) NASA Space Network Ground Segment Sustainment (SGSS) Project requirements for a “schedule request message”

Compare the draft SGSS schedule request message with the SCCS-SM-B-1 Create Service Package invocation

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Background

The proposed Blue-2 refactoring approach provides a framework adding new managed services and extending the managed services already covered by Blue-1

NASA SGSS is to implement SCCS-SM Blue-1 “to the greatest extent possible”, but SGSS will have schedule optimization mechanisms that are not supported by Blue-1’s Create Service Package operation

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Approach

Develop SGSS Schedule Request class diagrams equivalent to that of the Space Link Session Service Package Request selection in the <<ServicePackageRequest>> of SCCS-SM-B-1

Based on draft SGSS schema of 6 September 2011 Class diagram view is easier to see “big picture” concepts than schema

details Easier to compare to <<ServicePackageRequest>> class diagram

Covers only those features of importance to SGSS No attempt (in this iteration) to add back SCCS-SM-B-1 features not

used by SGSS

SCCS-SM refactoring concepts applied where it seems appropriate

A few minor differences between classes and schema types for purposes of cleaner class diagram representation

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<<ServicePackageRequest>> Class Diagram

scenarioId

ServiceScenario

transferServiceProfileRef

SlsTsProfileRespecification

0..*

1

1

1..*

1

1..*

spaceCommunicationServiceProfileRefspaceCommServiceStartTimespaceCommServiceStartTimeLeadspaceCommServiceStartTimeLagminimumServiceDurationpreferredServiceDurationtransferServicesDeferred : BooleansequenceOfEventsDeferred: BooleantimeReference

SpaceCommunicationServiceRequest

spaceLinkEventsProfileRef

SpaceLinkEventsProfileReference

0..*

1

parameterDistinguishedNameparameterValue

RespecifiedParameter

1..*

1

SpaceCommunicationServiceProfileRespecification

0..1

1

handoversPermittedImportanceprimeScenarioRef

SpaceLinkSessionServicePackageRequest

acceptabilityConstraintsType

AntennaConstraints0..11

antennaRefconstraintType

Antenna

1

1..*

trajectoryRef

TrajectoryReference

1

1..*

1..*

1

antennaReftransferServiceProfileRefaccessStartTimeaccessStopTime

RetrievalServicePackageRequest

RetrievalTsProfileRespecification

0..1

1

1..*

1

<<ServicePackageRequest>>

1

1

{xor}

1

1

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SGSS Schedule Request (Top Level)

7

EventSpecification

1

1

SpecificTime

1

1

<<extensionPoint>>RecurrentTime

1

1

{xor}

timeleadTolerance (opt.)lagTolerance (opt.)

StartTime

isPreferred (opt.)windowStartPref (opt.)

StartTimeWindow-Constraints

1

1

1

1..*{xor}

isExcluded (opt.)

TimeWindow-Constraints

1

0..1

identifierfreezeInterval

SgssScheduleRequest

<<extensionPoint>> LinkedEvent

1

0..*

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SGSS Schedule Request Comparison with CSP

No alternate scenarios SN will implement only a single “scenario”

No explicit trajectory references SN uses maintains a single trajectory for each supported spacecraft

Freeze interval parameter regulates how long CM can modify a request

Request can be for a single (specific) service package or a recurring service package

The specific request as a whole has a start time that is requested In contrast with the CSP, in which the components of the request have start times and

the start time of the service package is result of what is scheduled The start time can be around a single (preferred) start time or within any of a set of start

time windows

The specific request can be constrained to be within one of a defined set of windows

The SN groups services (carriers) by Event (the group of services provided through a single TDRS), not by single antenna (as in SCCS-SM SCSP)

Antenna selection is addressed later

Multiple events can be specified within the request, but one is primary ands the others are “linked” to it

No reason to put multiple events in the same package unless they are somehow related

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Time Window Classes

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isPreferred (opt.)windowStartPref (opt.)

StartTimeWindow-Constraints

isExcluded (opt.)


<<extensionPoint>>TimeWindow

1

1

1

1..*

startTimeduration

DefaultTimeWindow

eventRefstartOffsetduration

EventTimeWindow

timeWindowSetRef

ReferencedTime-WindowSet

weekdaystartTimeduration

WeekdayTimeWindow

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Recurrent Time

10

startTimeduration

<<extensionPoint>>RecurrentTime

isExcluded (opt.)


<<extensionPoint>>TimeWindow

1

0..1

eventsPerOrbit

Orbit

eventRef

OrbitEvent

PeriodeventsPerPeriod

Periodic

minimummaximumpreferred

DurationMinMaxPref

TimeBetweenEvents

1

0..1

StartTimeOffset1

1

networkResource-Ref

Network-ResourceView

StartTimeOffset1

1

initialUtilizationutilizationDuringEventutilizationBetweenEvents

Resource-Utilization

minimummaximum

Capacity

1

1

Window StartTimeOffset1

1

11..*TimeBetweenEvents

0..1

1

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Event Specification

11

identifier

EventSpecification

ExplicitEventSpecification

SplittableEventConstraints

1

0..1

maximumNumberOfSegments

MaximumNumberOf-Segments


MaximumConcurrent-Segments

1

0..1

1

10..1{xor}

SegmentDuration

SegmentSeparationDuration

1

1

serviceIduserServiceProfileRef

ServiceSpecification

1

1..*

NetworkResourceConstraints

1

0..1

resourceRef

ResourceRef

1

1..* UserResourceConstraints

resourceRef

ResourceRef

1

1..*

1

0..1

eventSpecificationReference

ReferencedEventSpecification

1

1

1

1

1

1{xor}


DurationMinMaxPref

points to Event Specification Profile

points to User Service Profile

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Service Specification Comparison with CSP

In today’s SN, services (carriers) in an Event can be specified either individually, or grouped in a pre-defined Prototype Event

Service (carrier) configuration parameters can be respecified only when the services are explicitly defined in the request

The Prototype Event notion is carried in SGSS as the Referenced Event Specification

SCCS-SM provides for scheduling groups of services (via predefined Space Communication Service Profiles), and allows respecification of parameters within those groups

This leads to a more-complicated respecification mechanism Can/should Blue-2 adopt the simpler SN/SGSS approach?

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Service Specification

13

1 1



DiscreteTime-ServiceSpecification

offsetleadTolerancelagTolerance

RelativeTime-WithTolerance StartTime

Duration

Minimumpreferred

DurationMinPref

11

serviceRef

CoupledTime-ServiceSpecification

StartTime

Duration

11

11

serviceRef

BoundTime-ServiceSpecificationDuration

1 1

<<extensionPoint>>ServiceTimeSpecification

1

1

RespecifiableParameter

1

0..*

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Service Specification Comparison (continued)

Services can be related to each other Alternative Coupled Bound

In SCCS-SM, all carriers can only be offset by a fixed time from the scheduled start time of the Space Communication Service

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Event Specification Profile

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eventSpecificationIdentifier

EventSpecificationProfile

SplittableEventConstraints

1

0..1

maximumNumberOfSegments

MaximumNumberOf-Segments


MaximumConcurrent-Segments

1

0..1

1

10..1{xor}

SegmentDuration

SegmentSeparationDuration

1

1



1

1..*

NetworkResourceConstraints

1

0..1

resourceRef

ResourceRef

1

1..* UserResourceConstraints

resourceRef

ResourceRef

1

1..*

1

0..1

1

1minimummaximumpreferred

DurationMinMaxPref

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Linked Event

16

EventSpecification

eventRef

<<extensionPoint>> LinkedEvent

1 1

preference

AlternateEventConstrainedRelative-

Time

isRequired

CoupledEvent

1

1

isRequired

BoundEvent

0..*

1


StartOffset StartTime-Window-

Constraints

1

1

1

1..*{xor}


1

0..*

1

1

Documents

NASA Space Network Ground Segment Sustainment (SGSS) Schedule Request SMWG Boulder, CO 31 October – 4 November 2011 John Pietras GST, Inc