November 2005

Stephen Braham

Slide 1

doc.: IEEE 802.11-05/1132r0

Submission

Requirements for Taking 802.11 Into Space

Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.

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Date: 2005-11-14

Name Company Address Phone email Stephen Braham Simon Fraser

University PolyLAB, SFU Vancouver 515 W. Hastings St. Vancouver, BC Canada V6B 5K3

+1 604 268-7981

sbraham@sfu.ca

Authors:

November 2005

Stephen Braham

Slide 2

doc.: IEEE 802.11-05/1132r0

Submission

Abstract

It is increasingly believed that using COTS communications standards may lead to more capable and flexible space systems, at reduced development

costs. Adopting IEEE 802.11 and other IEEE standards could enhance future industrial participation in

spaceflight, while providing a standard upgrade path for future technologies and standards. However, for IEEE 802.11n to be a good candidate standard for

planetary exploration, certain features are required. These features, based on results from analogue

planetary exploration, and expected requirements in future missions to the Moon, Mars, and beyond, are

described.

November 2005

Stephen Braham

Slide 3

doc.: IEEE 802.11-05/1132r0

Submission

Human Planetary Surface Exploration

November 2005

Stephen Braham

Slide 4

doc.: IEEE 802.11-05/1132r0

Submission

Important Timing for IEEE 802.11

• Following groups have plans to send humans to the Moon:– US (NASA, under mandate from President)

– Europe (ESA, under their Aurora program, just about to seek next-stage mandate)

– China (CNSA, emerging plans)

– Japan (JAXA, recently announced plans)

– Russia (RKA, discussions with both ESA and CNSA)

• Roughly the same timeframe – approx 2020, with long-term lunar bases, followed by missions to Mars

November 2005

Stephen Braham

Slide 5

doc.: IEEE 802.11-05/1132r0

Submission

Present vs. COTS - Present

• Presently a standards process for spaceflight communications, CCSDS– Composed primarily of heritage solutions handmade for

spaceflight– Based on old, non-standard, physical layers, and non-

standard upper layers (data link, network protocols)– But can absorb and move to more modern approaches– Starting to absorb Internet Protocols, but less movement

on physical layer– Emerging pressures to change to meet the needs of

human missions to the Moon and beyond

November 2005

Stephen Braham

Slide 6

doc.: IEEE 802.11-05/1132r0

Submission

Present vs. COTS - COTS

• Data and Software technologies derived from COTS will allow the following:– Greatly reduced development costs as we make needed

moves to more flexible systems– Enable autonomy and future upgrade– Allow many-magnitude jumps in performance and reliability– Allow us to meet timelines for human lunar missions– Increase use of Communications Industry in these missions

• Seeing some of these technologies on Space Station already

November 2005

Stephen Braham

Slide 7

doc.: IEEE 802.11-05/1132r0

Submission

CSA Exploration Systems Operations Centre Project (ExSOC)

• Component of the Canadian Space Agency (CSA) Canadian Analogue Research Network (CARN)

• Lead by SFU, following on years of previous work• New Multiyear Funding (two years initial, two

years follow-on) – Supports CSA-funded Analogue Research Sites performing science and

testing concepts and technology for planetary surface exploration– Provides planetary surface exploration systems, mission operations, and

missions concept design engineering expertise and on-site logistics-type engineering support

– Links analogue activities to requirements of actual surface exploration missions

– Looks for potential links to possible future missions to sites

November 2005

Stephen Braham

Slide 8

doc.: IEEE 802.11-05/1132r0

Submission

Wide Range of Future Needs (ESA-Industry Wireless WG Scenarios)

• Several appropriate opportunities for IEEE Wireless

ESA Concept

SFU Concept SEA Ltd. Concept

SFU

ESA Concordia

NASA

ESA

ESA

ESA

ESA

November 2005

Stephen Braham

Slide 9

doc.: IEEE 802.11-05/1132r0

Submission

Human spaceflight EASIER

• Human Lunar missions often compared to other mission choices like, for instance, robotic Mars missions

• Not such a hard road to follow, to take humans to the Moon with COTS:– Having humans in the loop requires many systems that operate in human-survivable

environment. Easy environmental requirements, large masses allowed, only rad and safety to worry about. Makes it easier to use advanced technology, instead of just high-heritage.

– Systems can be cheap - some NASA suppliers spend less than $1M to fly hardware on ISS, using COTS options, with a few months development time (sensor networks)

– Lunar missions can be a lot shorter than robotic Mars missions: far smaller rad dose.

– Starting human lunar systems development early possible, and highly beneficial to many areas of spaceflight

– Benefit even more from analogue field testing and training

November 2005

Stephen Braham

Slide 10

doc.: IEEE 802.11-05/1132r0

Submission

SFU Study-Derived Lunar Communications Requirements

• Meeting the communications and data requirements for these missions will not be simple;– Complex topography on planetary surfaces

– Non-line of Sight required on surface and on spacecraft

– Multipath environment, inside and outside habitat and spacecraft (ISS, Kliper, and beyond)

– Complex On-board Spacecraft data requirements, during transit and on surface

– Quality of Service requirements

– Integrated, layered, systems

– Require appropriate protocols, computing, and commmunications solutions, lots of them, with well-understood behavior

– Multi-layered Systems architecture needed

• Believe that must meet requirements using COTS technologies

November 2005

Stephen Braham

Slide 11

doc.: IEEE 802.11-05/1132r0

Submission

Emerging Result - Need to Embrace COTS

• Space Internet Workshops becoming dominant - yearly discussions of next-generation space internet solutions

• CCSDS recently (September 2003) started integrating IP into standard as an alternative, and eventually preferred mode (for RSVP, Mobile IP, and more) - result of SIW and Goddard and SFU results on IP in space mission (Goddard) and Deep Space conditions (SFU).

• IETF standards already becoming important. Time for IEEE.

• ESA Wireless Data Onboard Spacecraft Working Groups looking at how wireless communications can generate a quantum leap in capabilities, with many COTS physical layer (and above) solutions looking very promising and easy to qualify for spaceflight

• Analogue testing demonstrating need for COTS to allow solution of complex integration tasks in rich human operations environment

November 2005

Stephen Braham

Slide 12

doc.: IEEE 802.11-05/1132r0

Submission

What’s COTS when it comes to Space?

• Any of the following:– COTS Hardware and Software - true off the shelf– KOTS - Modified for flight qualification– COTS Derived - Say IP from COTS + Space hardware + COTS or

Modified SW, etc, etc– COTS Standards - Adoption of family of supported standards, from small

to large (eg IEEE 802.15.4 to 802.11b, g, n… and on to 802.16, 802.20)

• Includes potential use of true COTS in ground tests, and easy compatibility with operational ground systems

November 2005

Stephen Braham

Slide 13

doc.: IEEE 802.11-05/1132r0

Submission

ESA-Industry Wireless Working Group and COTS

• Robust COTS technologies exist to support very low data rates to very high rates: 20Kbps to 100Mbps+, depending on the application

• Improved RF behaviour

• Extensive built-in error correction, packet error handling, and forward error correction

• Protocols are inherently Internet Protocol (IP) suite (or derivative) enabled

• Newer technologies are increasingly becoming immune to multipath effects due to selective fading (multi-reflections): OFDM and ultra-wideband (UWB) are key to the emerging terrestrial wireless grid

• Miniaturisation already very mature for COTS wireless: Rad-Tolerant ASICS and FPGAs for space possible today at moderate cost

Back to basics: Why spread spectrum wireless such as DSSS, FH, OFDM and UWB for space?

November 2005

Stephen Braham

Slide 14

doc.: IEEE 802.11-05/1132r0

Submission

Multipath on the Moon and Mars – Why We Need OFDM and UWB. Mars like a City

Downtown.

Nirgal Vallis, Mars, THEMIS Image

Satellite CommsNot Possible

Satellite Comms Possible

MultipathDominantBut Required

November 2005

Stephen Braham

Slide 15

doc.: IEEE 802.11-05/1132r0

Submission

Haughton-Mars Project: Testings Comms for Moon (and Mars!), on Devon Island

• Canadian High Arctic• Twenty km Crater, 23 Mya• Hostile, permafrost, barren, bears• Moon-like and Mars-like! • Astrobiology• Geology• NASA and other Exploration technology studies - Spacesuits, robotic rovers,

human rovers, greenhouses / autonomous life-support, mission operations comms and more

• Biggest Planetary Analog exploration project in the world – roughly 150 researchers per year

• Massive press coverage (CNN, BBC, National Geographic, Discovery Channel, Channel 4, Daily Mail, and more)

• Field Engineering Management by SFU and CSA, MarsCanada and ExSOC

November 2005

Stephen Braham

Slide 16

doc.: IEEE 802.11-05/1132r0

Submission

Moonbase-like Configuration driven by Arctic Exploration Needs

November 2005

Stephen Braham

Slide 17

doc.: IEEE 802.11-05/1132r0

Submission

Complex Desert Terrain on Devon Island – Multipath Dominated

November 2005

Stephen Braham

Slide 18

doc.: IEEE 802.11-05/1132r0

Submission

Large Reflectors in a Moon-like (and Mars-like) environment

November 2005

Stephen Braham

Slide 19

doc.: IEEE 802.11-05/1132r0

Submission

IEEE 802.11b Not For Moon (3km, Wi-Fi, Line of Sight, in Lunar conditions)!

NASA HMP 802.11b DS Spacesuit Tests

Failed due to Multipath

Worked

Target ScienceArea

PlanetNet 1 and 2 worked, even when b-mode WiFi failed

November 2005

Stephen Braham

Slide 20

doc.: IEEE 802.11-05/1132r0

Submission

OFDM-based COTS Leading the Way• 3 km multipath echo (100 kilosymbols per second) from a hill

gives max communication rates of:– SFU PlanetNet 2: 77 Mbps (future, but conservative, OFDM, close to 802.16)– IEEE 802.11b DS (“Wi-Fi” wireless LAN): 100 Kbps (1/4 the speed of a cable modem).

Worse: observed total failure of present implementation.– CCSDS Proximity-1 (present NASA standard for Planetary surface comms): Expected

total failure

• Same technology basis for the IEEE 802.11g and IEEE 802.16, and proposed IEEE 802.11n standards

• Purely a COTS solution, but can be space-qualified for about US$5M, expected. Would cost upwards of US$1B to reproduce a special space version as a purely CCSDS system

• Issue: OFDM PAPR often considered an issue for spaceflight, though we believe protocols and pre-whitening can handle this.

November 2005

Stephen Braham

Slide 21

doc.: IEEE 802.11-05/1132r0

Submission

Layered Networking Concept

• SFU-led proposal to NASA under (now defunct) BAA process

• Large Canadian and US team, including 3 NASA Centres

• Communication system for traverse-capable planetary operations

November 2005

Stephen Braham

Slide 22

doc.: IEEE 802.11-05/1132r0

Submission

Layered Networking Requirements from HMP

• Long-range Surface Networking (habitat to resources)

• Short-hop Wireless Networking (vehicle to suits, internal suit)

• Sensor Networking (spacesuits and instruments)

• Interplanetary Networking (link to Earth, including protocols)

• Integrated

• Closely matched with ESA Wireless WG and NASA SIW concepts

• Can only be implemented easily via COTS

• Too many layers and technologies required for small-team development at low space-agency budgets

• Can already be implemented via COTS, looks easy to space qualify

November 2005

Stephen Braham

Slide 23

doc.: IEEE 802.11-05/1132r0

Submission

Primary Benefits of COTS-based and derived solutions

• Cheaper to space-qualify new technologies than invent in-house technologies; IT now big enough, compared to early spaceflight, that spin-in is more important than spin-off. 1% to 10% of costs, expected.

• Utilize technologies implemented in millions to billions of operational units, not dozens

• COTS standards compatibility means COTS systems can be used in ground systems, including analogue testing; industry can easily provide, and compete

• COTS interoperability means commercial standard software and commercial quality programmers can be used, instead of non-competitive in-house programmers.

• COTS allows commercial grade testing techniques, off-the-shelf test gear, many, many, many trained experts in each specialist components

• Less in-house unstable software• Indeed, many NASA and ESA researchers are realizing that UWB and OFDM-based

IEEE standards may be the way to go for spaceflight, and are advocating adopting them in baseline mission concepts for human missions.

November 2005

Stephen Braham

Slide 24

doc.: IEEE 802.11-05/1132r0

Submission

Requirements for Space• Need to support at least vehicle to spacesuit and internal

spacecraft comms (say data rates of 100-200 Mb/s at max symbol rates of 5 MS/s)

• Must be able to fight ISI (traverses) and Selective Fading (spacecraft and spacesuit interiors)

• Would be nice if extended to medium range (same data rates, 1 MS/s or less, few km point-to-point range)

• Needs to be low power (10W electrical max), low mass, including supporting processor (when space-qualified)

• Needs to play nice with Bluetooth, ZigBee, etc.• 600 Mb/s rates not that useful, but 54 Mbps a little slow. In-

between is good.• If OFDM, must have enough carriers, low (or mitigated) PAPR.

Hopefully eventually harmonized with 802.16, where long-range comms are possibly going for spaceflight.

November 2005

Stephen Braham

Slide 25

doc.: IEEE 802.11-05/1132r0

Submission

What it could do

• Internal human-crewed spacecraft

• Internal robotic spacecraft

• Communications between instruments and spacecraft

• Outside orbiting / transiting spacecraft or between spacecraft in constellations

• Medium and short-range comms on lunar and planetary surfaces

• Supporting – high rate stereoscopic, multispectral, video, advanced control and dataapplications, and more.

November 2005

Stephen Braham

Slide 26

doc.: IEEE 802.11-05/1132r0

Submission

Conclusions• COTS wireless comms, and particularly multipath-

resistant IEEE standards enable us for the next generation of spacecraft, for human missions to the Moon and beyond

• Disruptive! Adopting IEEE standards will change the way we do spaceflight

• Any space agency that doesn’t adopt IEEE standards-derived technologies will have serious problems with meeting cost and timeline pressures

• IEEE 802.11n and onwards will allow increased interoperability with space agencies, as same lessons are being learned everywhere

• But need to ensure that the standards meet our requirements