Transcript Cislunar Networking WG Overview

Consultative Committee
for Space Data Systems
Cislunar Networking
Working Group
Keith Scott
JPL Cislunar Workshop
16 June 2004
Pasadena, CA
© 2004 The MITRE Corporation. All rights reserved
Background

MITRE
– Not for profit, non-competitive, chartered in the public interest

Work in partnership with government, applying systems
engineering and advanced technology to issues of national
importance
– The MITRE corporation runs three Federally Funded Research
and Development Centers:

DOD

FAA

IRS
– Networking Center

Tactical military networks, Navy ForceNet, NCW, SATCOM, MobileIP,
…

Previous and current work with NASA/DoD on space
communications protocols and tactical applications
– Asked by Code-M to lead CCSDS working group on cislunar
and in-situ communications
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CCSDS

Consultative Committee for Space Data Systems (CCSDS)
– Members: Various nations’ space agencies

They fund people to work on CCSDS
– Develops international standards for communicating with and
among spacecraft

Standards enable (international) cross-support

Pool the small market for space communications hardware/software

Adopt, adapt, develop

Product: standards, some prototype implementations
– Six main areas within CCSDS:

System Engineering

Spacecraft On-board Interfaces

Space Internetworking

Space Link
Cross Support
- Cislunar Working Group


Mission Operations and
Information Management
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Cislunar Working Group

Kickoff meeting 14 May 2004 at Spring meetings
– International participation (ESA, BNSC, CSA, …)
– Presentations on:

Environment

Architectures

CCSDS and other protocols / capabilities
– Draft Charter

Current Status
– CCSDS has voted to form the working group
– In the process of allocating resources
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Cislunar WG Work Items

Define baseline communications architecture to support
lunar and in-situ communications
– Human and robotic
– Reuse (of existing technology, of this technology into future
environments, e.g. Mars in-situ)

Examine existing CCSDS protocols to determine how they
can be applied to the baseline architecture
– Centered on network, transport layers
– Update existing standards where appropriate
– Issues discovered related to link and application protocols will
be referred to relevant CCSDS areas (Space Link Services,
Applications)

Research new protocols for adoption by CCSDS*
– IETF standards (SCTP, LEMONADE, DCCP, and MIDCOM
working groups, …)
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*Probably not in time for 2008 lunar mission.
© 2004 The MITRE Corporation. All rights reserved
Lunar Communications Requirements

1969 Moon shot
–
–
–

Voice
Video
Minimal Data
2020 Moon shot
–
–
–
–
–
–
Voice
Videoconference
HDTV downlink
“Everyday” applications (email, web, …)
Operation in intermittently- connected
environments?
Tele-operation of robots
–
Lots of “stuff”

Networked architecture, not
a bunch of point-to-point
links
WASHINGTON (CNN) -- Saying "the desire to
explore and understand is part of our character,"
President Bush Wednesday unveiled an
ambitious plan to return Americans to the moon
by 2020 and use the mission as a steppingstone
for future manned trips to Mars and beyond.
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Networked Architecture

Efficient use of links, especially as the number of users
increases
vs.
f

f
Support for disconnected operations
– What if there’s no end-to-end path?

Simplified management: get away from “one spacecraft,
one (DTE) link”
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Communications Links
Lunar Surface
Lunar
Lander
Lunar
Rover
Surface
EVA(s)
Science
Inst.
Camera
Lunar Vicinity
Lunar
Orbiters
Earth
Earth
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Adapted from “LDRM Communication Operations Concept (Laura Hood, JSC)
© 2004 The MITRE Corporation. All rights reserved
End-to-End Networking Architecture
End-to-End
Space Applications
End-to-End
Space Applications
Space Application
Services
Space Application
Services
Space Transport
Services
Space Transport
Services
Networking
Services
Terrestrial Link
Services
Terrestrial Link
Services
Space Link
Services
Onboard Link
Services
Onboard Link
Services
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Gatewayed Transport / Networking
Architecture
End-to-End
Space Applications
End-to-End
Space Applications
Space Application
Services
Space Application
Services
Terrestrial Space
Transport Transport
Services Services
Terrestrial Transport
Services
Terrestrial Networking
Services
Terrestrial Link
Services
App
Space Networking
Services
Terrestrial Link
Services
Internet
Space Onboard
Transport Transport
Services Services
Space Link
Services
Ground
Station
Gateway
Space Link
Services
Onboard Transport
Services
Onboard Networking
Services
Onboard Link
Services
Onboard
Gateway
Onboard Link
Services
App
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End-to-End Space Applications
CFDP
Space Application
Services
Space Transport
Services
CCSDS Path
FTP, CCSDS FP
UDP
Space
Networking
Services
TCP
IPSec, CCSDS SP
IPv4, IPv6, CCSDS NP
CCSDS AOS, TM, TC
CCSDS Proximity 1
Currently Unspecified
CCSDS AOS/TM/TC Coding
CCSDS
Prox-1 Coding
Space
Networking
Services
Currently Unspecified
CCSDS RF & Mod
CCSDS RF & Mod
Currently Unspecified
Space Long Haul
Space Proximity
Space Surface
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Protocols
Lunar Surface
Lunar
Lander
Lunar
Rover
Surface
Proximity Link
Surface
EVA(s)
Science
Inst.
Camera
CCSDS Prox-1
CCSDS Advanced
Orbiting Sytems
(AOS), TC/TM
Lunar Vicinity
Lunar
Orbiters
Earth
Existing
Radios
Earth
Ground
Network
(NASA /commercial)
Space
Network
(TDRS)
Deep Space
Network (DSN)
Existing
Ground
Equip.
[CCSDS TC/TM
CCSDS AOS]
[CCSDS TC/TM
CCSDS AOS]
[CCSDS TC/TM
CCSDS AOS]
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Existing CCSDS Capabilities

Availability
– Commercial companies support CCSDS protocols

Speed
– CCSDS TC/TM/AOS Telemetry Processors available up to
400Mbps
– CCSDS Prox-1 implementation speeds?

Application support
– Support for streaming applications (voice)
– Support for applications built over IPv4, IPv6

Cross-Support
– Prox-1 cross-support demonstrated at Mars
image.gsfc.nasa.gov/publication/ document/dmr/image_dmr_5.html
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Related Technologies

Lemonade
– Enhancements and profiles of Internet email submission,
transport, and retrieval protocols to facilitate operation on
platforms with constrained resources, or communications links
with high latency or limited bandwidth

Datagram Congestion Control Protocol (DCCP)
– A minimal general purpose transport-layer protocol providing:


setup, maintenance and teardown of unreliable packet flows

congestion control of those flows.
Stream Control Transmission Protocol (SCTP)
– Think of it as “TCP+”: message boundaries, multiple streams,
support for multi-homing, …

Middlebox Communications (Midcom)
– How end hosts can discover and interact with proxies in the
middle of the network

IP-over-DVB (and other link technologies)
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Participation

CCSDS Information (participation, meeting schedule):
– http://www.ccsds.org

Cislunar WG mailing list:
– http://mailman.ccsds.org/cgi-bin/mailman/listinfo/sis-csi

Me:
– [email protected]
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© 2004 The MITRE Corporation. All rights reserved
Conclusions

Baseline architecture
– Looking at both end-to-end and gatewayed architectures
– CCSDS Protocol Suite


Flight-proven hardware and software

Supports target application set

CCSDS protocols installed and running in ground stations

Standards, interoperability, international cross-support
Lunar Relay Orbiter Recommendations
– Networked architecture. Go to at least layer 3 (network) in the
spacecraft


Because we want to get away from “one spacecraft, one DTE link”
If at all possible, provide the ability to experiment with technologies
like CFDP and DTN to support communications over disconnected
paths
– Support CCSDS AOS and Prox-1 protocols for Earth and Lunar
element comms., respectively

Existing commercial hardware, Software Defined Radio, …
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Strawman LRO Capabilities
Lunar Surface
Lunar
Lander
Lunar
Rover
Surface
Proximity Link
Surface
EVA(s)
Science
Inst.
Camera
CCSDS Prox-1
Lunar Vicinity
LRO
CCSDS Advanced
Orbiting Sytems
(AOS)
Earth
Earth
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Questions?
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Backups
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© 2004 The MITRE Corporation. All rights reserved
Some Data Points


Earth-Moon distance is 384,748 km (~1.28s one-way)
Earth-Mars distance varies between ~4 minutes and ~20
minutes (one-way)
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IETF Datagram Congestion Control
Protocol (dccp)

The Datagram Control Protocol working group is chartered
to develop and standardize the Datagram Congestion
Control Protocol (DCCP). DCCP is a minimal general
purpose transport-layer protocol providing only two core
functions:
– The establishment, maintenance and teardown of an unreliable
packet flow.
– Congestion control of that packet flow.
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© 2004 The MITRE Corporation. All rights reserved
IETF LEMONADE

Lemonade is tasked to provide a set of enhancements and
profiles of Internet email submission, transport, and
retrieval protocols to facilitate operation on platforms with
constrained resources, or communications links with high
latency or limited bandwidth. A primary goal of this work is
to ensure that those profiles and enhancements continue to
interoperate with the existing Internet email protocols in use
on the Internet, so that these environments and more
traditional Internet users have access to a seamless
service.
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© 2004 The MITRE Corporation. All rights reserved
IETF SCTP (RFC2960)

SCTP is a reliable transport protocol operating on top of a
connectionless packet network such as IP. It offers the
following services to its users:
– acknowledged error-free non-duplicated transfer of user data,
– data fragmentation to conform to discovered path MTU size
– sequenced delivery of user messages within multiple streams,
with an option for order-of-arrival delivery of individual user
messages
– optional bundling of multiple user messages into a single SCTP
packet
– network-level fault tolerance through supporting of multihoming at either or both ends of an association.

The design of SCTP includes appropriate congestion
avoidance behavior and resistance to flooding and
masquerade attacks.
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© 2004 The MITRE Corporation. All rights reserved
Middlebox Architectures

IETF midcom working group
– As trusted third parties are increasingly being asked to make
policy decisions on behalf of the various entities participating
in an application's operation, a need has developed for
applications to be able to communicate their needs to the
devices in the network that provide transport policy
enforcement. Examples of these devices include firewalls,
network address translators (both within and between address
families), signature management for intrusion detection
systems, and multimedia buffer management. These devices
are a subset of what can be referred to as 'middleboxes.'

SCPS-TP Gateways
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© 2004 The MITRE Corporation. All rights reserved
End-to-End Space Applications
Space Transport Services
Space Networking Services
Space Link Services
Space Long-Haul Data Link
Space Proximity Data Link
Space Surface Data Link
Space Long-Haul Coding
SpaceNetworking
Proximity Coding
Space
Services
Space Surface Coding
Space Long-Haul Channel
Space Proximity Channel
Space Surface Channel
SPACE PROTOCOL MODEL
Space Application Services
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Space Long Haul
Space Proximity
Space Surface
© 2004 The MITRE Corporation. All rights reserved
End-to-End Data Flow
Application Path
Services Service
Packet Transfer
Bitstream
Service
Virtual
Channel
Access
Service
Internet
Internet
Service
Internet
Packet Transfer
Path
Protocol
Virtual
Channel
Data
Unit
Internet
Insert
Service
Encapsulation
Service
IP
Encap.
Subnet
Subnet
Subnet
Subnet
Multiplexing
Bit
stream
Virtual Channel
Physical Channel
Onboard Network
Space Link Subnetwork
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© 2004 The MITRE Corporation. All rights reserved
CCSDS Multiplexing Service:
Switches packets in/out
of CCSDS Frames
CCSDS Virtual Channel
Access Service:
Relays a block of octets
across link via CCSDS Frame
CCSDS Path Service:
End-to-End
Data Flow
Provides efficient managed
end-end data transfer
CCSDS Encapsulation Service:
Wraps delimited data units
CCSDS Internet Service:
for
space link transfer
Email,
Provided IP or IP-like
Web, Chat
end-end data transfer
Application Path
CCSDS Bitstream Service:
Relays a stream of bits
across link via CCSDS Frame
CCSDS Virtual
Channel Data Unit
Service: Interleaves
CCSDS Frames
Bitstream
from different
Service
spacecraft
Virtual
Services Service
Packet Transfer
Channel
Access
Service
Internet
Internet
Service
Internet
Packet Transfer
Path
Protocol
Virtual
Channel
CCSDS
Insert
Data
Unit
Service:
Voice
Transfers
Insert
small
block
Service
Internet
of octets
isochronously
Encapsulation
Service
IP
Encap.
Subnet
Subnet
Subnet
Subnet
Multiplexing
Bit
stream
Virtual Channel
Physical Channel
Onboard Network
Space Link Subnetwork
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© 2004 The MITRE Corporation. All rights reserved