adding resilience and trust to gps

Adding Resilience & Trust to GPS

STL

Copyright Orolia January 2017

• New signal available today• Broadcast on the Iridium sats

• >30 dB stronger than GPS• Higher jamming and

interference resistance• Operates indoors

• Encrypted signal• Inherently anti-spoof• Subscription based service• Available for civilian use

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STL – Satellite Time & Location Signal

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The Ideal method for augmenting GPS to combat jamming and spoofing

Iridium STL

66 Iridium SatellitesGlobal coverage500 mile altitude1000x stronger

than GPS

24 GPS SatellitesGlobal coverage12,500 mile altitude25x further away

GPS

from


Signal Comparison to GPSGPS SPS L1 STL

Timing accuracy to UTC ~20 ns ~200 ns

Positioning accuracy ~3 meters 30-50 meters

Time To First Fix -- Timing ~100 seconds ~few seconds

Time To First Fix -- Positioning ~100 seconds ~10 minutes

Anti-spoofing No, only for military use Yes, encrypted signal

Coverage Global Global

Availability Outdoors With view of horizon to getaccurate position with low DOP

Limited view of sky lengthensconvergence time

Availability Indoors No Yes: 30 – 40 dB stronger

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• Re-purposed paging channels• 1620 MHz band, 25 KHz

channel, QPSK• Spread Spectrum coded

signal, 90 msec frame, ~1.4 sec burst on average

• UTC synchronized timing• +/- 500 nsec spec• 100-200 nsec typical

• Timing updates to a precision local oscillator for continuous time and frequency sourcing

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Timing signal - How it works


Sub-microsecond Timing Worldwide

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1 microsecond

STL Standard Deviation: STL Max Excursion:

0.057 microseconds0.332 microseconds


• Iridium: ~100 minute orbit• GPS: 12 hour orbit• Encrypted signal with

subscriber keys• Positioning determination

• Spot beam location (gross)• Range and Doppler updates• Convergence over minutes

• Geo-location security

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Low Earth Orbit (LEO) => Strong Signal with Spot Beams


Global STL Coverage


• Time Sync• Augment GPS with an independent

stronger signal• Anti spoof with subscriber

authenticationof encrypted signal

• Deep Indoor Penetration• No outdoor installation or cabling

required• 1000x stronger than GPS

• Trusted Location• Security based on geo-location

Benefits


Indoor Timing Solutions

• Network time synchronization currently requires GPS• Data Centers• Payment Card Compliance• Secure Facilities

• GPS roof antennas are a “nightmare”• Landlord permission / roof rights• Zoning restrictions in major cities• Building hazards (e.g. asbestos)• Outdoor equipment maintenance• Typical installation $10k + $1k/month

• Same needs apply to data centers

Building image from Greg Jacobs, Bicsi

GPS

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STL


STL – adding Resilience & Trust to GPS

GPSSTL

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A new service available from Spectracom

adding resilience and trust to gps

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